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Remove skb linearization #1

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planetA opened this issue Jul 24, 2020 · 0 comments
Open

Remove skb linearization #1

planetA opened this issue Jul 24, 2020 · 0 comments

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@planetA
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planetA commented Jul 24, 2020

Function rxe_udp_encap_recv is responsible for receiving the RoCE packets. For each packet, it linearizes the skb:

if (skb_linearize(skb)) {

This operation hurts performance a lot and must be removed from the critical path. Unfortunately, it requires non-trivial changes through the whole driver code, as accessing packet becomes less trivial.

planetA pushed a commit that referenced this issue Feb 10, 2023
Current imc-pmu code triggers a WARNING with CONFIG_DEBUG_ATOMIC_SLEEP
and CONFIG_PROVE_LOCKING enabled, while running a thread_imc event.

Command to trigger the warning:
  # perf stat -e thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/ sleep 5

   Performance counter stats for 'sleep 5':

                   0      thread_imc/CPM_CS_FROM_L4_MEM_X_DPTEG/

         5.002117947 seconds time elapsed

         0.000131000 seconds user
         0.001063000 seconds sys

Below is snippet of the warning in dmesg:

  BUG: sleeping function called from invalid context at kernel/locking/mutex.c:580
  in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 2869, name: perf-exec
  preempt_count: 2, expected: 0
  4 locks held by perf-exec/2869:
   #0: c00000004325c540 (&sig->cred_guard_mutex){+.+.}-{3:3}, at: bprm_execve+0x64/0xa90
   #1: c00000004325c5d8 (&sig->exec_update_lock){++++}-{3:3}, at: begin_new_exec+0x460/0xef0
   #2: c0000003fa99d4e0 (&cpuctx_lock){-...}-{2:2}, at: perf_event_exec+0x290/0x510
   #3: c000000017ab8418 (&ctx->lock){....}-{2:2}, at: perf_event_exec+0x29c/0x510
  irq event stamp: 4806
  hardirqs last  enabled at (4805): [<c000000000f65b94>] _raw_spin_unlock_irqrestore+0x94/0xd0
  hardirqs last disabled at (4806): [<c0000000003fae44>] perf_event_exec+0x394/0x510
  softirqs last  enabled at (0): [<c00000000013c404>] copy_process+0xc34/0x1ff0
  softirqs last disabled at (0): [<0000000000000000>] 0x0
  CPU: 36 PID: 2869 Comm: perf-exec Not tainted 6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  Call Trace:
    dump_stack_lvl+0x98/0xe0 (unreliable)
    __might_resched+0x2f8/0x310
    __mutex_lock+0x6c/0x13f0
    thread_imc_event_add+0xf4/0x1b0
    event_sched_in+0xe0/0x210
    merge_sched_in+0x1f0/0x600
    visit_groups_merge.isra.92.constprop.166+0x2bc/0x6c0
    ctx_flexible_sched_in+0xcc/0x140
    ctx_sched_in+0x20c/0x2a0
    ctx_resched+0x104/0x1c0
    perf_event_exec+0x340/0x510
    begin_new_exec+0x730/0xef0
    load_elf_binary+0x3f8/0x1e10
  ...
  do not call blocking ops when !TASK_RUNNING; state=2001 set at [<00000000fd63e7cf>] do_nanosleep+0x60/0x1a0
  WARNING: CPU: 36 PID: 2869 at kernel/sched/core.c:9912 __might_sleep+0x9c/0xb0
  CPU: 36 PID: 2869 Comm: sleep Tainted: G        W          6.2.0-rc2-00011-g1247637727f2 torvalds#61
  Hardware name: 8375-42A POWER9 0x4e1202 opal:v7.0-16-g9b85f7d961 PowerNV
  NIP:  c000000000194a1c LR: c000000000194a18 CTR: c000000000a78670
  REGS: c00000004d2134e0 TRAP: 0700   Tainted: G        W           (6.2.0-rc2-00011-g1247637727f2)
  MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  CR: 48002824  XER: 00000000
  CFAR: c00000000013fb64 IRQMASK: 1

The above warning triggered because the current imc-pmu code uses mutex
lock in interrupt disabled sections. The function mutex_lock()
internally calls __might_resched(), which will check if IRQs are
disabled and in case IRQs are disabled, it will trigger the warning.

Fix the issue by changing the mutex lock to spinlock.

Fixes: 8f95faa ("powerpc/powernv: Detect and create IMC device")
Reported-by: Michael Petlan <[email protected]>
Reported-by: Peter Zijlstra <[email protected]>
Signed-off-by: Kajol Jain <[email protected]>
[mpe: Fix comments, trim oops in change log, add reported-by tags]
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
planetA pushed a commit that referenced this issue Feb 10, 2023
When a match has been made to the nth duplicate symbol, return
success not error.

Example:

  Before:

    $ cat file.c
    cat: file.c: No such file or directory
    $ cat file1.c
    #include <stdio.h>

    static void func(void)
    {
            printf("First func\n");
    }

    void other(void);

    int main()
    {
            func();
            other();
            return 0;
    }
    $ cat file2.c
    #include <stdio.h>

    static void func(void)
    {
            printf("Second func\n");
    }

    void other(void)
    {
            func();
    }

    $ gcc -Wall -Wextra -o test file1.c file2.c
    $ perf record -e intel_pt//u --filter 'filter func @ ./test' -- ./test
    Multiple symbols with name 'func'
    #1      0x1149  l       func
                    which is near           main
    #2      0x1179  l       func
                    which is near           other
    Disambiguate symbol name by inserting #n after the name e.g. func #2
    Or select a global symbol by inserting #0 or #g or #G
    Failed to parse address filter: 'filter func @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.
    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    Failed to parse address filter: 'filter func #2 @ ./test'
    Filter format is: filter|start|stop|tracestop <start symbol or address> [/ <end symbol or size>] [@<file name>]
    Where multiple filters are separated by space or comma.

  After:

    $ perf record -e intel_pt//u --filter 'filter func #2 @ ./test' -- ./test
    First func
    Second func
    [ perf record: Woken up 1 times to write data ]
    [ perf record: Captured and wrote 0.016 MB perf.data ]
    $ perf script --itrace=b -Ftime,flags,ip,sym,addr --ns
    1231062.526977619:   tr strt                               0 [unknown] =>     558495708179 func
    1231062.526977619:   tr end  call               558495708188 func =>     558495708050 _init
    1231062.526979286:   tr strt                               0 [unknown] =>     55849570818d func
    1231062.526979286:   tr end  return             55849570818f func =>     55849570819d other

Fixes: 1b36c03 ("perf record: Add support for using symbols in address filters")
Reported-by: Dmitrii Dolgov <[email protected]>
Signed-off-by: Adrian Hunter <[email protected]>
Tested-by: Dmitry Dolgov <[email protected]>
Cc: Adrian Hunter <[email protected]>
Cc: Ian Rogers <[email protected]>
Cc: Jiri Olsa <[email protected]>
Cc: Namhyung Kim <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Arnaldo Carvalho de Melo <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
…kernel/git/kvmarm/kvmarm into kvm-master

KVM/arm64 fixes for 6.2, take #1

- Fix the PMCR_EL0 reset value after the PMU rework

- Correctly handle S2 fault triggered by a S1 page table walk
  by not always classifying it as a write, as this breaks on
  R/O memslots

- Document why we cannot exit with KVM_EXIT_MMIO when taking
  a write fault from a S1 PTW on a R/O memslot

- Put the Apple M2 on the naughty step for not being able to
  correctly implement the vgic SEIS feature, just liek the M1
  before it

- Reviewer updates: Alex is stepping down, replaced by Zenghui
planetA pushed a commit that referenced this issue Feb 10, 2023
[BUG]
There are some reports from the mailing list that since v6.1 kernel, the
WARN_ON() inside btrfs_qgroup_account_extent() gets triggered during
rescan:

  WARNING: CPU: 3 PID: 6424 at fs/btrfs/qgroup.c:2756 btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs]
  CPU: 3 PID: 6424 Comm: snapperd Tainted: P           OE      6.1.2-1-default #1 openSUSE Tumbleweed 05c7a1b1b61d5627475528f71f50444637b5aad7
  RIP: 0010:btrfs_qgroup_account_extents+0x1ae/0x260 [btrfs]
  Call Trace:
   <TASK>
  btrfs_commit_transaction+0x30c/0xb40 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]
   ? start_transaction+0xc3/0x5b0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]
  btrfs_qgroup_rescan+0x42/0xc0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]
   btrfs_ioctl+0x1ab9/0x25c0 [btrfs c39c9c546c241c593f03bd6d5f39ea1b676250f6]
   ? __rseq_handle_notify_resume+0xa9/0x4a0
   ? mntput_no_expire+0x4a/0x240
   ? __seccomp_filter+0x319/0x4d0
   __x64_sys_ioctl+0x90/0xd0
   do_syscall_64+0x5b/0x80
   ? syscall_exit_to_user_mode+0x17/0x40
   ? do_syscall_64+0x67/0x80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
  RIP: 0033:0x7fd9b790d9bf
   </TASK>

[CAUSE]
Since commit e15e9f4 ("btrfs: introduce
BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting"), if
our qgroup is already in inconsistent state, we will no longer do the
time-consuming backref walk.

This can leave some qgroup records without a valid old_roots ulist.
Normally this is fine, as btrfs_qgroup_account_extents() would also skip
those records if we have NO_ACCOUNTING flag set.

But there is a small window, if we have NO_ACCOUNTING flag set, and
inserted some qgroup_record without a old_roots ulist, but then the user
triggered a qgroup rescan.

During btrfs_qgroup_rescan(), we firstly clear NO_ACCOUNTING flag, then
commit current transaction.

And since we have a qgroup_record with old_roots = NULL, we trigger the
WARN_ON() during btrfs_qgroup_account_extents().

[FIX]
Unfortunately due to the introduction of NO_ACCOUNTING flag, the
assumption that every qgroup_record would have its old_roots populated
is no longer correct.

Fix the false alerts and drop the WARN_ON().

Reported-by: Lukas Straub <[email protected]>
Reported-by: HanatoK <[email protected]>
Fixes: e15e9f4 ("btrfs: introduce BTRFS_QGROUP_RUNTIME_FLAG_NO_ACCOUNTING to skip qgroup accounting")
CC: [email protected] # 6.1
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Signed-off-by: Qu Wenruo <[email protected]>
Signed-off-by: David Sterba <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
Patch series "mm/hugetlb: uffd-wp fixes for hugetlb_change_protection()".

Playing with virtio-mem and background snapshots (using uffd-wp) on
hugetlb in QEMU, I managed to trigger a VM_BUG_ON().  Looking into the
details, hugetlb_change_protection() seems to not handle uffd-wp correctly
in all cases.

Patch #1 fixes my test case.  I don't have reproducers for patch #2, as it
requires running into migration entries.

I did not yet check in detail yet if !hugetlb code requires similar care.


This patch (of 2):

There are two problematic cases when stumbling over a PTE marker in
hugetlb_change_protection():

(1) We protect an uffd-wp PTE marker a second time using uffd-wp: we will
    end up in the "!huge_pte_none(pte)" case and mess up the PTE marker.

(2) We unprotect a uffd-wp PTE marker: we will similarly end up in the
    "!huge_pte_none(pte)" case even though we cleared the PTE, because
    the "pte" variable is stale. We'll mess up the PTE marker.

For example, if we later stumble over such a "wrongly modified" PTE marker,
we'll treat it like a present PTE that maps some garbage page.

This can, for example, be triggered by mapping a memfd backed by huge
pages, registering uffd-wp, uffd-wp'ing an unmapped page and (a)
uffd-wp'ing it a second time; or (b) uffd-unprotecting it; or (c)
unregistering uffd-wp. Then, ff we trigger fallocate(FALLOC_FL_PUNCH_HOLE)
on that file range, we will run into a VM_BUG_ON:

[  195.039560] page:00000000ba1f2987 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x0
[  195.039565] flags: 0x7ffffc0001000(reserved|node=0|zone=0|lastcpupid=0x1fffff)
[  195.039568] raw: 0007ffffc0001000 ffffe742c0000008 ffffe742c0000008 0000000000000000
[  195.039569] raw: 0000000000000000 0000000000000000 00000001ffffffff 0000000000000000
[  195.039569] page dumped because: VM_BUG_ON_PAGE(compound && !PageHead(page))
[  195.039573] ------------[ cut here ]------------
[  195.039574] kernel BUG at mm/rmap.c:1346!
[  195.039579] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[  195.039581] CPU: 7 PID: 4777 Comm: qemu-system-x86 Not tainted 6.0.12-200.fc36.x86_64 #1
[  195.039583] Hardware name: LENOVO 20WNS1F81N/20WNS1F81N, BIOS N35ET50W (1.50 ) 09/15/2022
[  195.039584] RIP: 0010:page_remove_rmap+0x45b/0x550
[  195.039588] Code: [...]
[  195.039589] RSP: 0018:ffffbc03c3633ba8 EFLAGS: 00010292
[  195.039591] RAX: 0000000000000040 RBX: ffffe742c0000000 RCX: 0000000000000000
[  195.039592] RDX: 0000000000000002 RSI: ffffffff8e7aac1a RDI: 00000000ffffffff
[  195.039592] RBP: 0000000000000001 R08: 0000000000000000 R09: ffffbc03c3633a08
[  195.039593] R10: 0000000000000003 R11: ffffffff8f146328 R12: ffff9b04c42754b0
[  195.039594] R13: ffffffff8fcc6328 R14: ffffbc03c3633c80 R15: ffff9b0484ab9100
[  195.039595] FS:  00007fc7aaf68640(0000) GS:ffff9b0bbf7c0000(0000) knlGS:0000000000000000
[  195.039596] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  195.039597] CR2: 000055d402c49110 CR3: 0000000159392003 CR4: 0000000000772ee0
[  195.039598] PKRU: 55555554
[  195.039599] Call Trace:
[  195.039600]  <TASK>
[  195.039602]  __unmap_hugepage_range+0x33b/0x7d0
[  195.039605]  unmap_hugepage_range+0x55/0x70
[  195.039608]  hugetlb_vmdelete_list+0x77/0xa0
[  195.039611]  hugetlbfs_fallocate+0x410/0x550
[  195.039612]  ? _raw_spin_unlock_irqrestore+0x23/0x40
[  195.039616]  vfs_fallocate+0x12e/0x360
[  195.039618]  __x64_sys_fallocate+0x40/0x70
[  195.039620]  do_syscall_64+0x58/0x80
[  195.039623]  ? syscall_exit_to_user_mode+0x17/0x40
[  195.039624]  ? do_syscall_64+0x67/0x80
[  195.039626]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  195.039628] RIP: 0033:0x7fc7b590651f
[  195.039653] Code: [...]
[  195.039654] RSP: 002b:00007fc7aaf66e70 EFLAGS: 00000293 ORIG_RAX: 000000000000011d
[  195.039655] RAX: ffffffffffffffda RBX: 0000558ef4b7f370 RCX: 00007fc7b590651f
[  195.039656] RDX: 0000000018000000 RSI: 0000000000000003 RDI: 000000000000000c
[  195.039657] RBP: 0000000008000000 R08: 0000000000000000 R09: 0000000000000073
[  195.039658] R10: 0000000008000000 R11: 0000000000000293 R12: 0000000018000000
[  195.039658] R13: 00007fb8bbe00000 R14: 000000000000000c R15: 0000000000001000
[  195.039661]  </TASK>

Fix it by not going into the "!huge_pte_none(pte)" case if we stumble over
an exclusive marker.  spin_unlock() + continue would get the job done.

However, instead, make it clearer that there are no fall-through
statements: we process each case (hwpoison, migration, marker, !none,
none) and then unlock the page table to continue with the next PTE.  Let's
avoid "continue" statements and use a single spin_unlock() at the end.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 60dfaad ("mm/hugetlb: allow uffd wr-protect none ptes")
Signed-off-by: David Hildenbrand <[email protected]>
Reviewed-by: Peter Xu <[email protected]>
Reviewed-by: Mike Kravetz <[email protected]>
Cc: Miaohe Lin <[email protected]>
Cc: Muchun Song <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
If nilfs2 reads a corrupted disk image and tries to reads a b-tree node
block by calling __nilfs_btree_get_block() against an invalid virtual
block address, it returns -ENOENT because conversion of the virtual block
address to a disk block address fails.  However, this return value is the
same as the internal code that b-tree lookup routines return to indicate
that the block being searched does not exist, so functions that operate on
that b-tree may misbehave.

When nilfs_btree_insert() receives this spurious 'not found' code from
nilfs_btree_do_lookup(), it misunderstands that the 'not found' check was
successful and continues the insert operation using incomplete lookup path
data, causing the following crash:

 general protection fault, probably for non-canonical address
 0xdffffc0000000005: 0000 [#1] PREEMPT SMP KASAN
 KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
 ...
 RIP: 0010:nilfs_btree_get_nonroot_node fs/nilfs2/btree.c:418 [inline]
 RIP: 0010:nilfs_btree_prepare_insert fs/nilfs2/btree.c:1077 [inline]
 RIP: 0010:nilfs_btree_insert+0x6d3/0x1c10 fs/nilfs2/btree.c:1238
 Code: bc 24 80 00 00 00 4c 89 f8 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89
 ff e8 4b 02 92 fe 4d 8b 3f 49 83 c7 28 4c 89 f8 48 c1 e8 03 <42> 80 3c
 28 00 74 08 4c 89 ff e8 2e 02 92 fe 4d 8b 3f 49 83 c7 02
 ...
 Call Trace:
 <TASK>
  nilfs_bmap_do_insert fs/nilfs2/bmap.c:121 [inline]
  nilfs_bmap_insert+0x20d/0x360 fs/nilfs2/bmap.c:147
  nilfs_get_block+0x414/0x8d0 fs/nilfs2/inode.c:101
  __block_write_begin_int+0x54c/0x1a80 fs/buffer.c:1991
  __block_write_begin fs/buffer.c:2041 [inline]
  block_write_begin+0x93/0x1e0 fs/buffer.c:2102
  nilfs_write_begin+0x9c/0x110 fs/nilfs2/inode.c:261
  generic_perform_write+0x2e4/0x5e0 mm/filemap.c:3772
  __generic_file_write_iter+0x176/0x400 mm/filemap.c:3900
  generic_file_write_iter+0xab/0x310 mm/filemap.c:3932
  call_write_iter include/linux/fs.h:2186 [inline]
  new_sync_write fs/read_write.c:491 [inline]
  vfs_write+0x7dc/0xc50 fs/read_write.c:584
  ksys_write+0x177/0x2a0 fs/read_write.c:637
  do_syscall_x64 arch/x86/entry/common.c:50 [inline]
  do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 ...
 </TASK>

This patch fixes the root cause of this problem by replacing the error
code that __nilfs_btree_get_block() returns on block address conversion
failure from -ENOENT to another internal code -EINVAL which means that the
b-tree metadata is corrupted.

By returning -EINVAL, it propagates without glitches, and for all relevant
b-tree operations, functions in the upper bmap layer output an error
message indicating corrupted b-tree metadata via
nilfs_bmap_convert_error(), and code -EIO will be eventually returned as
it should be.

Link: https://lkml.kernel.org/r/[email protected]
Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Ryusuke Konishi <[email protected]>
Reported-by: [email protected]
Tested-by: Ryusuke Konishi <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
This lockdep splat says it better than I could:

================================
WARNING: inconsistent lock state
6.2.0-rc2-07010-ga9b9500ffaac-dirty torvalds#967 Not tainted
--------------------------------
inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
kworker/1:3/179 [HC0[0]:SC0[0]:HE1:SE1] takes:
ffff3ec4036ce098 (_xmit_ETHER#2){+.?.}-{3:3}, at: netif_freeze_queues+0x5c/0xc0
{IN-SOFTIRQ-W} state was registered at:
  _raw_spin_lock+0x5c/0xc0
  sch_direct_xmit+0x148/0x37c
  __dev_queue_xmit+0x528/0x111c
  ip6_finish_output2+0x5ec/0xb7c
  ip6_finish_output+0x240/0x3f0
  ip6_output+0x78/0x360
  ndisc_send_skb+0x33c/0x85c
  ndisc_send_rs+0x54/0x12c
  addrconf_rs_timer+0x154/0x260
  call_timer_fn+0xb8/0x3a0
  __run_timers.part.0+0x214/0x26c
  run_timer_softirq+0x3c/0x74
  __do_softirq+0x14c/0x5d8
  ____do_softirq+0x10/0x20
  call_on_irq_stack+0x2c/0x5c
  do_softirq_own_stack+0x1c/0x30
  __irq_exit_rcu+0x168/0x1a0
  irq_exit_rcu+0x10/0x40
  el1_interrupt+0x38/0x64
irq event stamp: 7825
hardirqs last  enabled at (7825): [<ffffdf1f7200cae4>] exit_to_kernel_mode+0x34/0x130
hardirqs last disabled at (7823): [<ffffdf1f708105f0>] __do_softirq+0x550/0x5d8
softirqs last  enabled at (7824): [<ffffdf1f7081050c>] __do_softirq+0x46c/0x5d8
softirqs last disabled at (7811): [<ffffdf1f708166e0>] ____do_softirq+0x10/0x20

other info that might help us debug this:
 Possible unsafe locking scenario:

       CPU0
       ----
  lock(_xmit_ETHER#2);
  <Interrupt>
    lock(_xmit_ETHER#2);

 *** DEADLOCK ***

3 locks held by kworker/1:3/179:
 #0: ffff3ec400004748 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #1: ffff80000a0bbdc8 ((work_completion)(&priv->tx_onestep_tstamp)){+.+.}-{0:0}, at: process_one_work+0x1f4/0x6c0
 #2: ffff3ec4036cd438 (&dev->tx_global_lock){+.+.}-{3:3}, at: netif_tx_lock+0x1c/0x34

Workqueue: events enetc_tx_onestep_tstamp
Call trace:
 print_usage_bug.part.0+0x208/0x22c
 mark_lock+0x7f0/0x8b0
 __lock_acquire+0x7c4/0x1ce0
 lock_acquire.part.0+0xe0/0x220
 lock_acquire+0x68/0x84
 _raw_spin_lock+0x5c/0xc0
 netif_freeze_queues+0x5c/0xc0
 netif_tx_lock+0x24/0x34
 enetc_tx_onestep_tstamp+0x20/0x100
 process_one_work+0x28c/0x6c0
 worker_thread+0x74/0x450
 kthread+0x118/0x11c

but I'll say it anyway: the enetc_tx_onestep_tstamp() work item runs in
process context, therefore with softirqs enabled (i.o.w., it can be
interrupted by a softirq). If we hold the netif_tx_lock() when there is
an interrupt, and the NET_TX softirq then gets scheduled, this will take
the netif_tx_lock() a second time and deadlock the kernel.

To solve this, use netif_tx_lock_bh(), which blocks softirqs from
running.

Fixes: 7294380 ("enetc: support PTP Sync packet one-step timestamping")
Signed-off-by: Vladimir Oltean <[email protected]>
Reviewed-by: Alexander Duyck <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
This reverts commit 13e5afd.

ieee80211_if_free() is already called from free_netdev(ndev)
because ndev->priv_destructor == ieee80211_if_free

syzbot reported:

general protection fault, probably for non-canonical address 0xdffffc0000000004: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000020-0x0000000000000027]
CPU: 0 PID: 10041 Comm: syz-executor.0 Not tainted 6.2.0-rc2-syzkaller-00388-g55b98837e37d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:pcpu_get_page_chunk mm/percpu.c:262 [inline]
RIP: 0010:pcpu_chunk_addr_search mm/percpu.c:1619 [inline]
RIP: 0010:free_percpu mm/percpu.c:2271 [inline]
RIP: 0010:free_percpu+0x186/0x10f0 mm/percpu.c:2254
Code: 80 3c 02 00 0f 85 f5 0e 00 00 48 8b 3b 48 01 ef e8 cf b3 0b 00 48 ba 00 00 00 00 00 fc ff df 48 8d 78 20 48 89 f9 48 c1 e9 03 <80> 3c 11 00 0f 85 3b 0e 00 00 48 8b 58 20 48 b8 00 00 00 00 00 fc
RSP: 0018:ffffc90004ba7068 EFLAGS: 00010002
RAX: 0000000000000000 RBX: ffff88823ffe2b80 RCX: 0000000000000004
RDX: dffffc0000000000 RSI: ffffffff81c1f4e7 RDI: 0000000000000020
RBP: ffffe8fffe8fc220 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 1ffffffff2179ab2 R12: ffff8880b983d000
R13: 0000000000000003 R14: 0000607f450fc220 R15: ffff88823ffe2988
FS: 00007fcb349de700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32220000 CR3: 000000004914f000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
netdev_run_todo+0x6bf/0x1100 net/core/dev.c:10352
ieee80211_register_hw+0x2663/0x4040 net/mac80211/main.c:1411
mac80211_hwsim_new_radio+0x2537/0x4d80 drivers/net/wireless/mac80211_hwsim.c:4583
hwsim_new_radio_nl+0xa09/0x10f0 drivers/net/wireless/mac80211_hwsim.c:5176
genl_family_rcv_msg_doit.isra.0+0x1e6/0x2d0 net/netlink/genetlink.c:968
genl_family_rcv_msg net/netlink/genetlink.c:1048 [inline]
genl_rcv_msg+0x4ff/0x7e0 net/netlink/genetlink.c:1065
netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2564
genl_rcv+0x28/0x40 net/netlink/genetlink.c:1076
netlink_unicast_kernel net/netlink/af_netlink.c:1330 [inline]
netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1356
netlink_sendmsg+0x91b/0xe10 net/netlink/af_netlink.c:1932
sock_sendmsg_nosec net/socket.c:714 [inline]
sock_sendmsg+0xd3/0x120 net/socket.c:734
____sys_sendmsg+0x712/0x8c0 net/socket.c:2476
___sys_sendmsg+0x110/0x1b0 net/socket.c:2530
__sys_sendmsg+0xf7/0x1c0 net/socket.c:2559
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

Reported-by: syzbot <[email protected]>
Fixes: 13e5afd ("wifi: mac80211: fix memory leak in ieee80211_if_add()")
Signed-off-by: Eric Dumazet <[email protected]>
Cc: Zhengchao Shao <[email protected]>
Cc: Johannes Berg <[email protected]>
Signed-off-by: Kalle Valo <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
planetA pushed a commit that referenced this issue Feb 10, 2023
…ter deref

If we have one task trying to start the quota rescan worker while another
one is trying to disable quotas, we can end up hitting a race that results
in the quota rescan worker doing a NULL pointer dereference. The steps for
this are the following:

1) Quotas are enabled;

2) Task A calls the quota rescan ioctl and enters btrfs_qgroup_rescan().
   It calls qgroup_rescan_init() which returns 0 (success) and then joins a
   transaction and commits it;

3) Task B calls the quota disable ioctl and enters btrfs_quota_disable().
   It clears the bit BTRFS_FS_QUOTA_ENABLED from fs_info->flags and calls
   btrfs_qgroup_wait_for_completion(), which returns immediately since the
   rescan worker is not yet running.
   Then it starts a transaction and locks fs_info->qgroup_ioctl_lock;

4) Task A queues the rescan worker, by calling btrfs_queue_work();

5) The rescan worker starts, and calls rescan_should_stop() at the start
   of its while loop, which results in 0 iterations of the loop, since
   the flag BTRFS_FS_QUOTA_ENABLED was cleared from fs_info->flags by
   task B at step 3);

6) Task B sets fs_info->quota_root to NULL;

7) The rescan worker tries to start a transaction and uses
   fs_info->quota_root as the root argument for btrfs_start_transaction().
   This results in a NULL pointer dereference down the call chain of
   btrfs_start_transaction(). The stack trace is something like the one
   reported in Link tag below:

   general protection fault, probably for non-canonical address 0xdffffc0000000041: 0000 [#1] PREEMPT SMP KASAN
   KASAN: null-ptr-deref in range [0x0000000000000208-0x000000000000020f]
   CPU: 1 PID: 34 Comm: kworker/u4:2 Not tainted 6.1.0-syzkaller-13872-gb6bb9676f216 #0
   Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
   Workqueue: btrfs-qgroup-rescan btrfs_work_helper
   RIP: 0010:start_transaction+0x48/0x10f0 fs/btrfs/transaction.c:564
   Code: 48 89 fb 48 (...)
   RSP: 0018:ffffc90000ab7ab0 EFLAGS: 00010206
   RAX: 0000000000000041 RBX: 0000000000000208 RCX: ffff88801779ba80
   RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
   RBP: dffffc0000000000 R08: 0000000000000001 R09: fffff52000156f5d
   R10: fffff52000156f5d R11: 1ffff92000156f5c R12: 0000000000000000
   R13: 0000000000000001 R14: 0000000000000001 R15: 0000000000000003
   FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
   CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
   CR2: 00007f2bea75b718 CR3: 000000001d0cc000 CR4: 00000000003506e0
   DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
   DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
   Call Trace:
    <TASK>
    btrfs_qgroup_rescan_worker+0x3bb/0x6a0 fs/btrfs/qgroup.c:3402
    btrfs_work_helper+0x312/0x850 fs/btrfs/async-thread.c:280
    process_one_work+0x877/0xdb0 kernel/workqueue.c:2289
    worker_thread+0xb14/0x1330 kernel/workqueue.c:2436
    kthread+0x266/0x300 kernel/kthread.c:376
    ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
    </TASK>
   Modules linked in:

So fix this by having the rescan worker function not attempt to start a
transaction if it didn't do any rescan work.

Reported-by: [email protected]
Link: https://lore.kernel.org/linux-btrfs/[email protected]/
Fixes: e804861 ("btrfs: fix deadlock between quota disable and qgroup rescan worker")
CC: [email protected] # 5.4+
Signed-off-by: Filipe Manana <[email protected]>
Signed-off-by: David Sterba <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
This attempts to fix the following trace:

kworker/u3:1/184 is trying to acquire lock:
ffff888001888130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_connect_cfm+0x2de/0x690

but task is already holding lock:
ffff8880028d1c20 (&conn->lock){+.+.}-{2:2}, at:
iso_connect_cfm+0x265/0x690

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #1 (&conn->lock){+.+.}-{2:2}:
       lock_acquire+0x176/0x3d0
       _raw_spin_lock+0x2a/0x40
       __iso_sock_close+0x1dd/0x4f0
       iso_sock_release+0xa0/0x1b0
       sock_close+0x5e/0x120
       __fput+0x102/0x410
       task_work_run+0xf1/0x160
       exit_to_user_mode_prepare+0x170/0x180
       syscall_exit_to_user_mode+0x19/0x50
       do_syscall_64+0x4e/0x90
       entry_SYSCALL_64_after_hwframe+0x62/0xcc

-> #0 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
       check_prev_add+0xfc/0x1190
       __lock_acquire+0x1e27/0x2750
       lock_acquire+0x176/0x3d0
       lock_sock_nested+0x32/0x80
       iso_connect_cfm+0x2de/0x690
       hci_cc_le_setup_iso_path+0x195/0x340
       hci_cmd_complete_evt+0x1ae/0x500
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

other info that might help us debug this:

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(&conn->lock);
                               lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
                               lock(&conn->lock);
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);

 *** DEADLOCK ***

Fixes: ccf74f2 ("Bluetooth: Add BTPROTO_ISO socket type")
Fixes: f764a6c ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
This fixes the following trace caused by attempting to lock
cmd_sync_work_lock while holding the rcu_read_lock:

kworker/u3:2/212 is trying to lock:
ffff888002600910 (&hdev->cmd_sync_work_lock){+.+.}-{3:3}, at:
hci_cmd_sync_queue+0xad/0x140
other info that might help us debug this:
context-{4:4}
4 locks held by kworker/u3:2/212:
 #0: ffff8880028c6530 ((wq_completion)hci0#2){+.+.}-{0:0}, at:
 process_one_work+0x4dc/0x9a0
 #1: ffff888001aafde0 ((work_completion)(&hdev->rx_work)){+.+.}-{0:0},
 at: process_one_work+0x4dc/0x9a0
 #2: ffff888002600070 (&hdev->lock){+.+.}-{3:3}, at:
 hci_cc_le_set_cig_params+0x64/0x4f0
 #3: ffffffffa5994b00 (rcu_read_lock){....}-{1:2}, at:
 hci_cc_le_set_cig_params+0x2f9/0x4f0

Fixes: 26afbd8 ("Bluetooth: Add initial implementation of CIS connections")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
This attempts to fix the following trace:

iso-tester/52 is trying to acquire lock:
ffff8880024e0070 (&hdev->lock){+.+.}-{3:3}, at:
iso_sock_listen+0x29e/0x440

but task is already holding lock:
ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
iso_sock_listen+0x8b/0x440

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-> #2 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}:
       lock_acquire+0x176/0x3d0
       lock_sock_nested+0x32/0x80
       iso_connect_cfm+0x1a3/0x630
       hci_cc_le_setup_iso_path+0x195/0x340
       hci_cmd_complete_evt+0x1ae/0x500
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

-> #1 (hci_cb_list_lock){+.+.}-{3:3}:
       lock_acquire+0x176/0x3d0
       __mutex_lock+0x13b/0xf50
       hci_le_remote_feat_complete_evt+0x17e/0x320
       hci_event_packet+0x38e/0x7c0
       hci_rx_work+0x34c/0x980
       process_one_work+0x5a5/0x9a0
       worker_thread+0x89/0x6f0
       kthread+0x14e/0x180
       ret_from_fork+0x22/0x30

-> #0 (&hdev->lock){+.+.}-{3:3}:
       check_prev_add+0xfc/0x1190
       __lock_acquire+0x1e27/0x2750
       lock_acquire+0x176/0x3d0
       __mutex_lock+0x13b/0xf50
       iso_sock_listen+0x29e/0x440
       __sys_listen+0xe6/0x160
       __x64_sys_listen+0x25/0x30
       do_syscall_64+0x42/0x90
       entry_SYSCALL_64_after_hwframe+0x62/0xcc

other info that might help us debug this:

Chain exists of:
  &hdev->lock --> hci_cb_list_lock --> sk_lock-AF_BLUETOOTH-BTPROTO_ISO

 Possible unsafe locking scenario:

       CPU0                    CPU1
       ----                    ----
  lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
                               lock(hci_cb_list_lock);
                               lock(sk_lock-AF_BLUETOOTH-BTPROTO_ISO);
  lock(&hdev->lock);

 *** DEADLOCK ***

1 lock held by iso-tester/52:
 #0: ffff888001978130 (sk_lock-AF_BLUETOOTH-BTPROTO_ISO){+.+.}-{0:0}, at:
 iso_sock_listen+0x8b/0x440

Fixes: f764a6c ("Bluetooth: ISO: Add broadcast support")
Signed-off-by: Luiz Augusto von Dentz <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
The cited commit changed class of tc_ht internal mutex in order to avoid
false lock dependency with fs_core node and flow_table hash table
structures. However, hash table implementation internally also includes a
workqueue task with its own lockdep map which causes similar bogus lockdep
splat[0]. Fix it by also adding dedicated class for hash table workqueue
work structure of tc_ht.

[0]:

[ 1139.672465] ======================================================
[ 1139.673552] WARNING: possible circular locking dependency detected
[ 1139.674635] 6.1.0_for_upstream_debug_2022_12_12_17_02 #1 Not tainted
[ 1139.675734] ------------------------------------------------------
[ 1139.676801] modprobe/5998 is trying to acquire lock:
[ 1139.677726] ffff88811e7b93b8 (&node->lock){++++}-{3:3}, at: down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.679662]
               but task is already holding lock:
[ 1139.680703] ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0
[ 1139.682223]
               which lock already depends on the new lock.

[ 1139.683640]
               the existing dependency chain (in reverse order) is:
[ 1139.684887]
               -> #2 (&tc_ht_lock_key){+.+.}-{3:3}:
[ 1139.685975]        __mutex_lock+0x12c/0x14b0
[ 1139.686659]        rht_deferred_worker+0x35/0x1540
[ 1139.687405]        process_one_work+0x7c2/0x1310
[ 1139.688134]        worker_thread+0x59d/0xec0
[ 1139.688820]        kthread+0x28f/0x330
[ 1139.689444]        ret_from_fork+0x1f/0x30
[ 1139.690106]
               -> #1 ((work_completion)(&ht->run_work)){+.+.}-{0:0}:
[ 1139.691250]        __flush_work+0xe8/0x900
[ 1139.691915]        __cancel_work_timer+0x2ca/0x3f0
[ 1139.692655]        rhashtable_free_and_destroy+0x22/0x6f0
[ 1139.693472]        del_sw_flow_table+0x22/0xb0 [mlx5_core]
[ 1139.694592]        tree_put_node+0x24c/0x450 [mlx5_core]
[ 1139.695686]        tree_remove_node+0x6e/0x100 [mlx5_core]
[ 1139.696803]        mlx5_destroy_flow_table+0x187/0x690 [mlx5_core]
[ 1139.698017]        mlx5e_tc_nic_cleanup+0x2f8/0x400 [mlx5_core]
[ 1139.699217]        mlx5e_cleanup_nic_rx+0x2b/0x210 [mlx5_core]
[ 1139.700397]        mlx5e_detach_netdev+0x19d/0x2b0 [mlx5_core]
[ 1139.701571]        mlx5e_suspend+0xdb/0x140 [mlx5_core]
[ 1139.702665]        mlx5e_remove+0x89/0x190 [mlx5_core]
[ 1139.703756]        auxiliary_bus_remove+0x52/0x70
[ 1139.704492]        device_release_driver_internal+0x3c1/0x600
[ 1139.705360]        bus_remove_device+0x2a5/0x560
[ 1139.706080]        device_del+0x492/0xb80
[ 1139.706724]        mlx5_rescan_drivers_locked+0x194/0x6a0 [mlx5_core]
[ 1139.707961]        mlx5_unregister_device+0x7a/0xa0 [mlx5_core]
[ 1139.709138]        mlx5_uninit_one+0x5f/0x160 [mlx5_core]
[ 1139.710252]        remove_one+0xd1/0x160 [mlx5_core]
[ 1139.711297]        pci_device_remove+0x96/0x1c0
[ 1139.722721]        device_release_driver_internal+0x3c1/0x600
[ 1139.723590]        unbind_store+0x1b1/0x200
[ 1139.724259]        kernfs_fop_write_iter+0x348/0x520
[ 1139.725019]        vfs_write+0x7b2/0xbf0
[ 1139.725658]        ksys_write+0xf3/0x1d0
[ 1139.726292]        do_syscall_64+0x3d/0x90
[ 1139.726942]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.727769]
               -> #0 (&node->lock){++++}-{3:3}:
[ 1139.728698]        __lock_acquire+0x2cf5/0x62f0
[ 1139.729415]        lock_acquire+0x1c1/0x540
[ 1139.730076]        down_write+0x8e/0x1f0
[ 1139.730709]        down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.731841]        mlx5_del_flow_rules+0x6f/0x610 [mlx5_core]
[ 1139.732982]        __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core]
[ 1139.734207]        mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core]
[ 1139.735491]        mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core]
[ 1139.736716]        mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core]
[ 1139.738007]        mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core]
[ 1139.739213]        mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core]
[ 1139.740377]        _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core]
[ 1139.741534]        rhashtable_free_and_destroy+0x3be/0x6f0
[ 1139.742351]        mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core]
[ 1139.743512]        mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core]
[ 1139.744683]        mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core]
[ 1139.745860]        mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core]
[ 1139.747098]        mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
[ 1139.748372]        mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core]
[ 1139.749590]        __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core]
[ 1139.750813]        mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core]
[ 1139.752147]        mlx5e_rep_remove+0x62/0x80 [mlx5_core]
[ 1139.753293]        auxiliary_bus_remove+0x52/0x70
[ 1139.754028]        device_release_driver_internal+0x3c1/0x600
[ 1139.754885]        driver_detach+0xc1/0x180
[ 1139.755553]        bus_remove_driver+0xef/0x2e0
[ 1139.756260]        auxiliary_driver_unregister+0x16/0x50
[ 1139.757059]        mlx5e_rep_cleanup+0x19/0x30 [mlx5_core]
[ 1139.758207]        mlx5e_cleanup+0x12/0x30 [mlx5_core]
[ 1139.759295]        mlx5_cleanup+0xc/0x49 [mlx5_core]
[ 1139.760384]        __x64_sys_delete_module+0x2b5/0x450
[ 1139.761166]        do_syscall_64+0x3d/0x90
[ 1139.761827]        entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.762663]
               other info that might help us debug this:

[ 1139.763925] Chain exists of:
                 &node->lock --> (work_completion)(&ht->run_work) --> &tc_ht_lock_key

[ 1139.765743]  Possible unsafe locking scenario:

[ 1139.766688]        CPU0                    CPU1
[ 1139.767399]        ----                    ----
[ 1139.768111]   lock(&tc_ht_lock_key);
[ 1139.768704]                                lock((work_completion)(&ht->run_work));
[ 1139.769869]                                lock(&tc_ht_lock_key);
[ 1139.770770]   lock(&node->lock);
[ 1139.771326]
                *** DEADLOCK ***

[ 1139.772345] 2 locks held by modprobe/5998:
[ 1139.772994]  #0: ffff88813c1ff0e8 (&dev->mutex){....}-{3:3}, at: device_release_driver_internal+0x8d/0x600
[ 1139.774399]  #1: ffff88813c1f96a0 (&tc_ht_lock_key){+.+.}-{3:3}, at: rhashtable_free_and_destroy+0x38/0x6f0
[ 1139.775822]
               stack backtrace:
[ 1139.776579] CPU: 3 PID: 5998 Comm: modprobe Not tainted 6.1.0_for_upstream_debug_2022_12_12_17_02 #1
[ 1139.777935] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-0-gf21b5a4aeb02-prebuilt.qemu.org 04/01/2014
[ 1139.779529] Call Trace:
[ 1139.779992]  <TASK>
[ 1139.780409]  dump_stack_lvl+0x57/0x7d
[ 1139.781015]  check_noncircular+0x278/0x300
[ 1139.781687]  ? print_circular_bug+0x460/0x460
[ 1139.782381]  ? rcu_read_lock_sched_held+0x3f/0x70
[ 1139.783121]  ? lock_release+0x487/0x7c0
[ 1139.783759]  ? orc_find.part.0+0x1f1/0x330
[ 1139.784423]  ? mark_lock.part.0+0xef/0x2fc0
[ 1139.785091]  __lock_acquire+0x2cf5/0x62f0
[ 1139.785754]  ? register_lock_class+0x18e0/0x18e0
[ 1139.786483]  lock_acquire+0x1c1/0x540
[ 1139.787093]  ? down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.788195]  ? lockdep_hardirqs_on_prepare+0x3f0/0x3f0
[ 1139.788978]  ? register_lock_class+0x18e0/0x18e0
[ 1139.789715]  down_write+0x8e/0x1f0
[ 1139.790292]  ? down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.791380]  ? down_write_killable+0x220/0x220
[ 1139.792080]  ? find_held_lock+0x2d/0x110
[ 1139.792713]  down_write_ref_node+0x7c/0xe0 [mlx5_core]
[ 1139.793795]  mlx5_del_flow_rules+0x6f/0x610 [mlx5_core]
[ 1139.794879]  __mlx5_eswitch_del_rule+0xdd/0x560 [mlx5_core]
[ 1139.796032]  ? __esw_offloads_unload_rep+0xd0/0xd0 [mlx5_core]
[ 1139.797227]  ? xa_load+0x11a/0x200
[ 1139.797800]  ? __xa_clear_mark+0xf0/0xf0
[ 1139.798438]  mlx5_eswitch_del_offloaded_rule+0x14/0x20 [mlx5_core]
[ 1139.799660]  mlx5e_tc_rule_unoffload+0x104/0x2b0 [mlx5_core]
[ 1139.800821]  mlx5e_tc_unoffload_fdb_rules+0x10c/0x1f0 [mlx5_core]
[ 1139.802049]  ? mlx5_eswitch_get_uplink_priv+0x25/0x80 [mlx5_core]
[ 1139.803260]  mlx5e_tc_del_fdb_flow+0xc3c/0xfa0 [mlx5_core]
[ 1139.804398]  ? __cancel_work_timer+0x1c2/0x3f0
[ 1139.805099]  ? mlx5e_tc_unoffload_from_slow_path+0x460/0x460 [mlx5_core]
[ 1139.806387]  mlx5e_tc_del_flow+0x146/0xa20 [mlx5_core]
[ 1139.807481]  _mlx5e_tc_del_flow+0x38/0x60 [mlx5_core]
[ 1139.808564]  rhashtable_free_and_destroy+0x3be/0x6f0
[ 1139.809336]  ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core]
[ 1139.809336]  ? mlx5e_tc_del_flow+0xa20/0xa20 [mlx5_core]
[ 1139.810455]  mlx5e_tc_ht_cleanup+0x1b/0x30 [mlx5_core]
[ 1139.811552]  mlx5e_cleanup_rep_tx+0x4a/0xe0 [mlx5_core]
[ 1139.812655]  mlx5e_detach_netdev+0x1ca/0x2b0 [mlx5_core]
[ 1139.813768]  mlx5e_netdev_change_profile+0xd9/0x1c0 [mlx5_core]
[ 1139.814952]  mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
[ 1139.816166]  mlx5e_vport_rep_unload+0x16a/0x1b0 [mlx5_core]
[ 1139.817336]  __esw_offloads_unload_rep+0xb1/0xd0 [mlx5_core]
[ 1139.818507]  mlx5_eswitch_unregister_vport_reps+0x409/0x5f0 [mlx5_core]
[ 1139.819788]  ? mlx5_eswitch_uplink_get_proto_dev+0x30/0x30 [mlx5_core]
[ 1139.821051]  ? kernfs_find_ns+0x137/0x310
[ 1139.821705]  mlx5e_rep_remove+0x62/0x80 [mlx5_core]
[ 1139.822778]  auxiliary_bus_remove+0x52/0x70
[ 1139.823449]  device_release_driver_internal+0x3c1/0x600
[ 1139.824240]  driver_detach+0xc1/0x180
[ 1139.824842]  bus_remove_driver+0xef/0x2e0
[ 1139.825504]  auxiliary_driver_unregister+0x16/0x50
[ 1139.826245]  mlx5e_rep_cleanup+0x19/0x30 [mlx5_core]
[ 1139.827322]  mlx5e_cleanup+0x12/0x30 [mlx5_core]
[ 1139.828345]  mlx5_cleanup+0xc/0x49 [mlx5_core]
[ 1139.829382]  __x64_sys_delete_module+0x2b5/0x450
[ 1139.830119]  ? module_flags+0x300/0x300
[ 1139.830750]  ? task_work_func_match+0x50/0x50
[ 1139.831440]  ? task_work_cancel+0x20/0x20
[ 1139.832088]  ? lockdep_hardirqs_on_prepare+0x273/0x3f0
[ 1139.832873]  ? syscall_enter_from_user_mode+0x1d/0x50
[ 1139.833661]  ? trace_hardirqs_on+0x2d/0x100
[ 1139.834328]  do_syscall_64+0x3d/0x90
[ 1139.834922]  entry_SYSCALL_64_after_hwframe+0x46/0xb0
[ 1139.835700] RIP: 0033:0x7f153e71288b
[ 1139.836302] Code: 73 01 c3 48 8b 0d 9d 75 0e 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 6d 75 0e 00 f7 d8 64 89 01 48
[ 1139.838866] RSP: 002b:00007ffe0a3ed938 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[ 1139.840020] RAX: ffffffffffffffda RBX: 0000564c2cbf8220 RCX: 00007f153e71288b
[ 1139.841043] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 0000564c2cbf8288
[ 1139.842072] RBP: 0000564c2cbf8220 R08: 0000000000000000 R09: 0000000000000000
[ 1139.843094] R10: 00007f153e7a3ac0 R11: 0000000000000206 R12: 0000564c2cbf8288
[ 1139.844118] R13: 0000000000000000 R14: 0000564c2cbf7ae8 R15: 00007ffe0a3efcb8

Fixes: 9ba3333 ("net/mlx5e: Avoid false lock depenency warning on tc_ht")
Signed-off-by: Vlad Buslov <[email protected]>
Reviewed-by: Eli Cohen <[email protected]>
Reviewed-by: Roi Dayan <[email protected]>
Signed-off-by: Saeed Mahameed <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
…ction

Since there is no protection for vd, a kernel panic will be
triggered here in exceptional cases.

You can refer to the processing of axi_chan_block_xfer_complete function

The triggered kernel panic is as follows:

[   67.848444] Unable to handle kernel NULL pointer dereference at virtual address 0000000000000060
[   67.848447] Mem abort info:
[   67.848449]   ESR = 0x96000004
[   67.848451]   EC = 0x25: DABT (current EL), IL = 32 bits
[   67.848454]   SET = 0, FnV = 0
[   67.848456]   EA = 0, S1PTW = 0
[   67.848458] Data abort info:
[   67.848460]   ISV = 0, ISS = 0x00000004
[   67.848462]   CM = 0, WnR = 0
[   67.848465] user pgtable: 4k pages, 48-bit VAs, pgdp=00000800c4c0b000
[   67.848468] [0000000000000060] pgd=0000000000000000, p4d=0000000000000000
[   67.848472] Internal error: Oops: 96000004 [#1] SMP
[   67.848475] Modules linked in: dmatest
[   67.848479] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.10.100-emu_x2rc+ torvalds#11
[   67.848483] pstate: 62000085 (nZCv daIf -PAN -UAO +TCO BTYPE=--)
[   67.848487] pc : axi_chan_handle_err+0xc4/0x230
[   67.848491] lr : axi_chan_handle_err+0x30/0x230
[   67.848493] sp : ffff0803fe55ae50
[   67.848495] x29: ffff0803fe55ae50 x28: ffff800011212200
[   67.848500] x27: ffff0800c42c0080 x26: ffff0800c097c080
[   67.848504] x25: ffff800010d33880 x24: ffff80001139d850
[   67.848508] x23: ffff0800c097c168 x22: 0000000000000000
[   67.848512] x21: 0000000000000080 x20: 0000000000002000
[   67.848517] x19: ffff0800c097c080 x18: 0000000000000000
[   67.848521] x17: 0000000000000000 x16: 0000000000000000
[   67.848525] x15: 0000000000000000 x14: 0000000000000000
[   67.848529] x13: 0000000000000000 x12: 0000000000000040
[   67.848533] x11: ffff0800c0400248 x10: ffff0800c040024a
[   67.848538] x9 : ffff800010576cd4 x8 : ffff0800c0400270
[   67.848542] x7 : 0000000000000000 x6 : ffff0800c04003e0
[   67.848546] x5 : ffff0800c0400248 x4 : ffff0800c4294480
[   67.848550] x3 : dead000000000100 x2 : dead000000000122
[   67.848555] x1 : 0000000000000100 x0 : ffff0800c097c168
[   67.848559] Call trace:
[   67.848562]  axi_chan_handle_err+0xc4/0x230
[   67.848566]  dw_axi_dma_interrupt+0xf4/0x590
[   67.848569]  __handle_irq_event_percpu+0x60/0x220
[   67.848573]  handle_irq_event+0x64/0x120
[   67.848576]  handle_fasteoi_irq+0xc4/0x220
[   67.848580]  __handle_domain_irq+0x80/0xe0
[   67.848583]  gic_handle_irq+0xc0/0x138
[   67.848585]  el1_irq+0xc8/0x180
[   67.848588]  arch_cpu_idle+0x14/0x2c
[   67.848591]  default_idle_call+0x40/0x16c
[   67.848594]  do_idle+0x1f0/0x250
[   67.848597]  cpu_startup_entry+0x2c/0x60
[   67.848600]  rest_init+0xc0/0xcc
[   67.848603]  arch_call_rest_init+0x14/0x1c
[   67.848606]  start_kernel+0x4cc/0x500
[   67.848610] Code: eb0002ff 9a9f12d6 f2fbd5a2 f2fbd5a3 (a94602c1)
[   67.848613] ---[ end trace 585a97036f88203a ]---

Signed-off-by: Shawn.Shao <[email protected]>
Cc: [email protected]
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
The first time dma_chan_get() is called for a channel the channel
client_count is incorrectly incremented twice for public channels,
first in balance_ref_count(), and again prior to returning. This
results in an incorrect client count which will lead to the
channel resources not being freed when they should be. A simple
 test of repeated module load and unload of async_tx on a Dell
 Power Edge R7425 also shows this resulting in a kref underflow
 warning.

[  124.329662] async_tx: api initialized (async)
[  129.000627] async_tx: api initialized (async)
[  130.047839] ------------[ cut here ]------------
[  130.052472] refcount_t: underflow; use-after-free.
[  130.057279] WARNING: CPU: 3 PID: 19364 at lib/refcount.c:28
refcount_warn_saturate+0xba/0x110
[  130.065811] Modules linked in: async_tx(-) rfkill intel_rapl_msr
intel_rapl_common amd64_edac edac_mce_amd ipmi_ssif kvm_amd dcdbas kvm
mgag200 drm_shmem_helper acpi_ipmi irqbypass drm_kms_helper ipmi_si
syscopyarea sysfillrect rapl pcspkr ipmi_devintf sysimgblt fb_sys_fops
k10temp i2c_piix4 ipmi_msghandler acpi_power_meter acpi_cpufreq vfat
fat drm fuse xfs libcrc32c sd_mod t10_pi sg ahci crct10dif_pclmul
libahci crc32_pclmul crc32c_intel ghash_clmulni_intel igb megaraid_sas
i40e libata i2c_algo_bit ccp sp5100_tco dca dm_mirror dm_region_hash
dm_log dm_mod [last unloaded: async_tx]
[  130.117361] CPU: 3 PID: 19364 Comm: modprobe Kdump: loaded Not
tainted 5.14.0-185.el9.x86_64 #1
[  130.126091] Hardware name: Dell Inc. PowerEdge R7425/02MJ3T, BIOS
1.18.0 01/17/2022
[  130.133806] RIP: 0010:refcount_warn_saturate+0xba/0x110
[  130.139041] Code: 01 01 e8 6d bd 55 00 0f 0b e9 72 9d 8a 00 80 3d
26 18 9c 01 00 75 85 48 c7 c7 f8 a3 03 9d c6 05 16 18 9c 01 01 e8 4a
bd 55 00 <0f> 0b e9 4f 9d 8a 00 80 3d 01 18 9c 01 00 0f 85 5e ff ff ff
48 c7
[  130.157807] RSP: 0018:ffffbf98898afe68 EFLAGS: 00010286
[  130.163036] RAX: 0000000000000000 RBX: ffff9da06028e598 RCX: 0000000000000000
[  130.170172] RDX: ffff9daf9de26480 RSI: ffff9daf9de198a0 RDI: ffff9daf9de198a0
[  130.177316] RBP: ffff9da7cddf3970 R08: 0000000000000000 R09: 00000000ffff7fff
[  130.184459] R10: ffffbf98898afd00 R11: ffffffff9d9e8c28 R12: ffff9da7cddf1970
[  130.191596] R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
[  130.198739] FS:  00007f646435c740(0000) GS:ffff9daf9de00000(0000)
knlGS:0000000000000000
[  130.206832] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  130.212586] CR2: 00007f6463b214f0 CR3: 00000008ab98c000 CR4: 00000000003506e0
[  130.219729] Call Trace:
[  130.222192]  <TASK>
[  130.224305]  dma_chan_put+0x10d/0x110
[  130.227988]  dmaengine_put+0x7a/0xa0
[  130.231575]  __do_sys_delete_module.constprop.0+0x178/0x280
[  130.237157]  ? syscall_trace_enter.constprop.0+0x145/0x1d0
[  130.242652]  do_syscall_64+0x5c/0x90
[  130.246240]  ? exc_page_fault+0x62/0x150
[  130.250178]  entry_SYSCALL_64_after_hwframe+0x63/0xcd
[  130.255243] RIP: 0033:0x7f6463a3f5ab
[  130.258830] Code: 73 01 c3 48 8b 0d 75 a8 1b 00 f7 d8 64 89 01 48
83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa b8 b0 00 00
00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 45 a8 1b 00 f7 d8 64 89
01 48
[  130.277591] RSP: 002b:00007fff22f972c8 EFLAGS: 00000206 ORIG_RAX:
00000000000000b0
[  130.285164] RAX: ffffffffffffffda RBX: 000055b6786edd40 RCX: 00007f6463a3f5ab
[  130.292303] RDX: 0000000000000000 RSI: 0000000000000800 RDI: 000055b6786edda8
[  130.299443] RBP: 000055b6786edd40 R08: 0000000000000000 R09: 0000000000000000
[  130.306584] R10: 00007f6463b9eac0 R11: 0000000000000206 R12: 000055b6786edda8
[  130.313731] R13: 0000000000000000 R14: 000055b6786edda8 R15: 00007fff22f995f8
[  130.320875]  </TASK>
[  130.323081] ---[ end trace eff7156d56b5cf25 ]---

cat /sys/class/dma/dma0chan*/in_use would get the wrong result.
2
2
2

Fixes: d2f4f99 ("dmaengine: Rework dma_chan_get")
Signed-off-by: Koba Ko <[email protected]>
Reviewed-by: Jie Hai <[email protected]>
Test-by: Jie Hai <[email protected]>
Reviewed-by: Jerry Snitselaar <[email protected]>
Reviewed-by: Dave Jiang <[email protected]>
Tested-by: Joel Savitz <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Vinod Koul <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
There is a lock inversion and rwsem read-lock recursion in the devfreq
target callback which can lead to deadlocks.

Specifically, ufshcd_devfreq_scale() already holds a clk_scaling_lock
read lock when toggling the write booster, which involves taking the
dev_cmd mutex before taking another clk_scaling_lock read lock.

This can lead to a deadlock if another thread:

  1) tries to acquire the dev_cmd and clk_scaling locks in the correct
     order, or

  2) takes a clk_scaling write lock before the attempt to take the
     clk_scaling read lock a second time.

Fix this by dropping the clk_scaling_lock before toggling the write booster
as was done before commit 0e9d4ca ("scsi: ufs: Protect some contexts
from unexpected clock scaling").

While the devfreq callbacks are already serialised, add a second
serialising mutex to handle the unlikely case where a callback triggered
through the devfreq sysfs interface is racing with a request to disable
clock scaling through the UFS controller 'clkscale_enable' sysfs
attribute. This could otherwise lead to the write booster being left
disabled after having disabled clock scaling.

Also take the new mutex in ufshcd_clk_scaling_allow() to make sure that any
pending write booster update has completed on return.

Note that this currently only affects Qualcomm platforms since commit
87bd050 ("scsi: ufs: core: Allow host driver to disable wb toggling
during clock scaling").

The lock inversion (i.e. 1 above) was reported by lockdep as:

 ======================================================
 WARNING: possible circular locking dependency detected
 6.1.0-next-20221216 torvalds#211 Not tainted
 ------------------------------------------------------
 kworker/u16:2/71 is trying to acquire lock:
 ffff076280ba98a0 (&hba->dev_cmd.lock){+.+.}-{3:3}, at: ufshcd_query_flag+0x50/0x1c0

 but task is already holding lock:
 ffff076280ba9cf0 (&hba->clk_scaling_lock){++++}-{3:3}, at: ufshcd_devfreq_scale+0x2b8/0x380

 which lock already depends on the new lock.
[  +0.011606]
 the existing dependency chain (in reverse order) is:

 -> #1 (&hba->clk_scaling_lock){++++}-{3:3}:
        lock_acquire+0x68/0x90
        down_read+0x58/0x80
        ufshcd_exec_dev_cmd+0x70/0x2c0
        ufshcd_verify_dev_init+0x68/0x170
        ufshcd_probe_hba+0x398/0x1180
        ufshcd_async_scan+0x30/0x320
        async_run_entry_fn+0x34/0x150
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 -> #0 (&hba->dev_cmd.lock){+.+.}-{3:3}:
        __lock_acquire+0x12a0/0x2240
        lock_acquire.part.0+0xcc/0x220
        lock_acquire+0x68/0x90
        __mutex_lock+0x98/0x430
        mutex_lock_nested+0x2c/0x40
        ufshcd_query_flag+0x50/0x1c0
        ufshcd_query_flag_retry+0x64/0x100
        ufshcd_wb_toggle+0x5c/0x120
        ufshcd_devfreq_scale+0x2c4/0x380
        ufshcd_devfreq_target+0xf4/0x230
        devfreq_set_target+0x84/0x2f0
        devfreq_update_target+0xc4/0xf0
        devfreq_monitor+0x38/0x1f0
        process_one_work+0x288/0x6c0
        worker_thread+0x74/0x450
        kthread+0x118/0x120
        ret_from_fork+0x10/0x20

 other info that might help us debug this:
  Possible unsafe locking scenario:
        CPU0                    CPU1
        ----                    ----
   lock(&hba->clk_scaling_lock);
                                lock(&hba->dev_cmd.lock);
                                lock(&hba->clk_scaling_lock);
   lock(&hba->dev_cmd.lock);

  *** DEADLOCK ***

Fixes: 0e9d4ca ("scsi: ufs: Protect some contexts from unexpected clock scaling")
Cc: [email protected]      # 5.12
Cc: Can Guo <[email protected]>
Tested-by: Andrew Halaney <[email protected]>
Signed-off-by: Johan Hovold <[email protected]>
Reviewed-by: Bart Van Assche <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Martin K. Petersen <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
The commit 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura
free") uses the get/put_cpu() to protect the usage of percpu pointer
in ->aura_freeptr() callback, but it also unnecessarily disable the
preemption for the blockable memory allocation. The commit 87b93b6
("octeontx2-pf: Avoid use of GFP_KERNEL in atomic context") tried to
fix these sleep inside atomic warnings. But it only fix the one for
the non-rt kernel. For the rt kernel, we still get the similar warnings
like below.
  BUG: sleeping function called from invalid context at kernel/locking/spinlock_rt.c:46
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  RCU nest depth: 0, expected: 0
  3 locks held by swapper/0/1:
   #0: ffff800009fc5fe8 (rtnl_mutex){+.+.}-{3:3}, at: rtnl_lock+0x24/0x30
   #1: ffff000100c276c0 (&mbox->lock){+.+.}-{3:3}, at: otx2_init_hw_resources+0x8c/0x3a4
   #2: ffffffbfef6537e0 (&cpu_rcache->lock){+.+.}-{2:2}, at: alloc_iova_fast+0x1ac/0x2ac
  Preemption disabled at:
  [<ffff800008b1908c>] otx2_rq_aura_pool_init+0x14c/0x284
  CPU: 20 PID: 1 Comm: swapper/0 Tainted: G        W          6.2.0-rc3-rt1-yocto-preempt-rt #1
  Hardware name: Marvell OcteonTX CN96XX board (DT)
  Call trace:
   dump_backtrace.part.0+0xe8/0xf4
   show_stack+0x20/0x30
   dump_stack_lvl+0x9c/0xd8
   dump_stack+0x18/0x34
   __might_resched+0x188/0x224
   rt_spin_lock+0x64/0x110
   alloc_iova_fast+0x1ac/0x2ac
   iommu_dma_alloc_iova+0xd4/0x110
   __iommu_dma_map+0x80/0x144
   iommu_dma_map_page+0xe8/0x260
   dma_map_page_attrs+0xb4/0xc0
   __otx2_alloc_rbuf+0x90/0x150
   otx2_rq_aura_pool_init+0x1c8/0x284
   otx2_init_hw_resources+0xe4/0x3a4
   otx2_open+0xf0/0x610
   __dev_open+0x104/0x224
   __dev_change_flags+0x1e4/0x274
   dev_change_flags+0x2c/0x7c
   ic_open_devs+0x124/0x2f8
   ip_auto_config+0x180/0x42c
   do_one_initcall+0x90/0x4dc
   do_basic_setup+0x10c/0x14c
   kernel_init_freeable+0x10c/0x13c
   kernel_init+0x2c/0x140
   ret_from_fork+0x10/0x20

Of course, we can shuffle the get/put_cpu() to only wrap the invocation
of ->aura_freeptr() as what commit 87b93b6 does. But there are only
two ->aura_freeptr() callbacks, otx2_aura_freeptr() and
cn10k_aura_freeptr(). There is no usage of perpcu variable in the
otx2_aura_freeptr() at all, so the get/put_cpu() seems redundant to it.
We can move the get/put_cpu() into the corresponding callback which
really has the percpu variable usage and avoid the sprinkling of
get/put_cpu() in several places.

Fixes: 4af1b64 ("octeontx2-pf: Fix lmtst ID used in aura free")
Signed-off-by: Kevin Hao <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Paolo Abeni <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
Run the following tests on the qemu platform:

syzkaller:~# modprobe speakup_audptr
 input: Speakup as /devices/virtual/input/input4
 initialized device: /dev/synth, node (MAJOR 10, MINOR 125)
 speakup 3.1.6: initialized
 synth name on entry is: (null)
 synth probe

spk_ttyio_initialise_ldisc failed because tty_kopen_exclusive returned
failed (errno -16), then remove the module, we will get a null-ptr-defer
problem, as follow:

syzkaller:~# modprobe -r speakup_audptr
 releasing synth audptr
 BUG: kernel NULL pointer dereference, address: 0000000000000080
 #PF: supervisor write access in kernel mode
 #PF: error_code(0x0002) - not-present page
 PGD 0 P4D 0
 Oops: 0002 [#1] PREEMPT SMP PTI
 CPU: 2 PID: 204 Comm: modprobe Not tainted 6.1.0-rc6-dirty #1
 RIP: 0010:mutex_lock+0x14/0x30
 Call Trace:
 <TASK>
  spk_ttyio_release+0x19/0x70 [speakup]
  synth_release.part.6+0xac/0xc0 [speakup]
  synth_remove+0x56/0x60 [speakup]
  __x64_sys_delete_module+0x156/0x250
  ? fpregs_assert_state_consistent+0x1d/0x50
  do_syscall_64+0x37/0x90
  entry_SYSCALL_64_after_hwframe+0x63/0xcd
 </TASK>
 Modules linked in: speakup_audptr(-) speakup
 Dumping ftrace buffer:

in_synth->dev was not initialized during modprobe, so we add check
for in_synth->dev to fix this bug.

Fixes: 4f2a81f ("speakup: Reference synth from tty and tty from synth")
Cc: stable <[email protected]>
Signed-off-by: Gaosheng Cui <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Samuel Thibault <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
Commit f1e5250 ("x86/boot: Skip realmode init code when running as
Xen PV guest") missed one code path accessing real_mode_header, leading
to dereferencing NULL when suspending the system under Xen:

    [  348.284004] PM: suspend entry (deep)
    [  348.289532] Filesystems sync: 0.005 seconds
    [  348.291545] Freezing user space processes ... (elapsed 0.000 seconds) done.
    [  348.292457] OOM killer disabled.
    [  348.292462] Freezing remaining freezable tasks ... (elapsed 0.104 seconds) done.
    [  348.396612] printk: Suspending console(s) (use no_console_suspend to debug)
    [  348.749228] PM: suspend devices took 0.352 seconds
    [  348.769713] ACPI: EC: interrupt blocked
    [  348.816077] BUG: kernel NULL pointer dereference, address: 000000000000001c
    [  348.816080] #PF: supervisor read access in kernel mode
    [  348.816081] #PF: error_code(0x0000) - not-present page
    [  348.816083] PGD 0 P4D 0
    [  348.816086] Oops: 0000 [#1] PREEMPT SMP NOPTI
    [  348.816089] CPU: 0 PID: 6764 Comm: systemd-sleep Not tainted 6.1.3-1.fc32.qubes.x86_64 #1
    [  348.816092] Hardware name: Star Labs StarBook/StarBook, BIOS 8.01 07/03/2022
    [  348.816093] RIP: e030:acpi_get_wakeup_address+0xc/0x20

Fix that by adding an optional acpi callback allowing to skip setting
the wakeup address, as in the Xen PV case this will be handled by the
hypervisor anyway.

Fixes: f1e5250 ("x86/boot: Skip realmode init code when running as Xen PV guest")
Reported-by: Marek Marczykowski-Górecki <[email protected]>
Signed-off-by: Juergen Gross <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Acked-by: Rafael J. Wysocki <[email protected]>
Link: https://lore.kernel.org/all/20230117155724.22940-1-jgross%40suse.com
planetA pushed a commit that referenced this issue Feb 10, 2023
The vmci_dispatch_dgs() tasklet function calls vmci_read_data()
which uses wait_event() resulting in invalid sleep in an atomic
context (and therefore potentially in a deadlock).

Use threaded irqs to fix this issue and completely remove usage
of tasklets.

[   20.264639] BUG: sleeping function called from invalid context at drivers/misc/vmw_vmci/vmci_guest.c:145
[   20.264643] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 762, name: vmtoolsd
[   20.264645] preempt_count: 101, expected: 0
[   20.264646] RCU nest depth: 0, expected: 0
[   20.264647] 1 lock held by vmtoolsd/762:
[   20.264648]  #0: ffff0000874ae440 (sk_lock-AF_VSOCK){+.+.}-{0:0}, at: vsock_connect+0x60/0x330 [vsock]
[   20.264658] Preemption disabled at:
[   20.264659] [<ffff80000151d7d8>] vmci_send_datagram+0x44/0xa0 [vmw_vmci]
[   20.264665] CPU: 0 PID: 762 Comm: vmtoolsd Not tainted 5.19.0-0.rc8.20220727git39c3c396f813.60.fc37.aarch64 #1
[   20.264667] Hardware name: VMware, Inc. VBSA/VBSA, BIOS VEFI 12/31/2020
[   20.264668] Call trace:
[   20.264669]  dump_backtrace+0xc4/0x130
[   20.264672]  show_stack+0x24/0x80
[   20.264673]  dump_stack_lvl+0x88/0xb4
[   20.264676]  dump_stack+0x18/0x34
[   20.264677]  __might_resched+0x1a0/0x280
[   20.264679]  __might_sleep+0x58/0x90
[   20.264681]  vmci_read_data+0x74/0x120 [vmw_vmci]
[   20.264683]  vmci_dispatch_dgs+0x64/0x204 [vmw_vmci]
[   20.264686]  tasklet_action_common.constprop.0+0x13c/0x150
[   20.264688]  tasklet_action+0x40/0x50
[   20.264689]  __do_softirq+0x23c/0x6b4
[   20.264690]  __irq_exit_rcu+0x104/0x214
[   20.264691]  irq_exit_rcu+0x1c/0x50
[   20.264693]  el1_interrupt+0x38/0x6c
[   20.264695]  el1h_64_irq_handler+0x18/0x24
[   20.264696]  el1h_64_irq+0x68/0x6c
[   20.264697]  preempt_count_sub+0xa4/0xe0
[   20.264698]  _raw_spin_unlock_irqrestore+0x64/0xb0
[   20.264701]  vmci_send_datagram+0x7c/0xa0 [vmw_vmci]
[   20.264703]  vmci_datagram_dispatch+0x84/0x100 [vmw_vmci]
[   20.264706]  vmci_datagram_send+0x2c/0x40 [vmw_vmci]
[   20.264709]  vmci_transport_send_control_pkt+0xb8/0x120 [vmw_vsock_vmci_transport]
[   20.264711]  vmci_transport_connect+0x40/0x7c [vmw_vsock_vmci_transport]
[   20.264713]  vsock_connect+0x278/0x330 [vsock]
[   20.264715]  __sys_connect_file+0x8c/0xc0
[   20.264718]  __sys_connect+0x84/0xb4
[   20.264720]  __arm64_sys_connect+0x2c/0x3c
[   20.264721]  invoke_syscall+0x78/0x100
[   20.264723]  el0_svc_common.constprop.0+0x68/0x124
[   20.264724]  do_el0_svc+0x38/0x4c
[   20.264725]  el0_svc+0x60/0x180
[   20.264726]  el0t_64_sync_handler+0x11c/0x150
[   20.264728]  el0t_64_sync+0x190/0x194

Signed-off-by: Vishnu Dasa <[email protected]>
Suggested-by: Zack Rusin <[email protected]>
Reported-by: Nadav Amit <[email protected]>
Reported-by: Nathan Chancellor <[email protected]>
Tested-by: Nathan Chancellor <[email protected]>
Fixes: 463713e ("VMCI: dma dg: add support for DMA datagrams receive")
Cc: <[email protected]> # v5.18+
Cc: VMware PV-Drivers Reviewers <[email protected]>
Cc: Greg Kroah-Hartman <[email protected]>
Cc: Bryan Tan <[email protected]>
Reviewed-by: Bryan Tan <[email protected]>
Reviewed-by: Zack Rusin <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
The page_pool_release_page was used when freeing rx buffers, and this
function just unmaps the page (if mapped) and does not recycle the page.
So after hundreds of down/up the eth0, the system will out of memory.
For more details, please refer to the following reproduce steps and
bug logs. To solve this issue and refer to the doc of page pool, the
page_pool_put_full_page should be used to replace page_pool_release_page.
Because this API will try to recycle the page if the page refcnt equal to
1. After testing 20000 times, the issue can not be reproduced anymore
(about testing 391 times the issue will occur on i.MX8MN-EVK before).

Reproduce steps:
Create the test script and run the script. The script content is as
follows:
LOOPS=20000
i=1
while [ $i -le $LOOPS ]
do
    echo "TINFO:ENET $curface up and down test $i times"
    org_macaddr=$(cat /sys/class/net/eth0/address)
    ifconfig eth0 down
    ifconfig eth0  hw ether $org_macaddr up
    i=$(expr $i + 1)
done
sleep 5
if cat /sys/class/net/eth0/operstate | grep 'up';then
    echo "TEST PASS"
else
    echo "TEST FAIL"
fi

Bug detail logs:
TINFO:ENET  up and down test 391 times
[  850.471205] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL)
[  853.535318] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[  853.541694] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[  870.590531] page_pool_release_retry() stalled pool shutdown 199 inflight 60 sec
[  931.006557] page_pool_release_retry() stalled pool shutdown 199 inflight 120 sec
TINFO:ENET  up and down test 392 times
[  991.426544] page_pool_release_retry() stalled pool shutdown 192 inflight 181 sec
[ 1051.838531] page_pool_release_retry() stalled pool shutdown 170 inflight 241 sec
[ 1093.751217] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL)
[ 1096.446520] page_pool_release_retry() stalled pool shutdown 308 inflight 60 sec
[ 1096.831245] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[ 1096.839092] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 1112.254526] page_pool_release_retry() stalled pool shutdown 103 inflight 302 sec
[ 1156.862533] page_pool_release_retry() stalled pool shutdown 308 inflight 120 sec
[ 1172.674516] page_pool_release_retry() stalled pool shutdown 103 inflight 362 sec
[ 1217.278532] page_pool_release_retry() stalled pool shutdown 308 inflight 181 sec
TINFO:ENET  up and down test 393 times
[ 1233.086535] page_pool_release_retry() stalled pool shutdown 103 inflight 422 sec
[ 1277.698513] page_pool_release_retry() stalled pool shutdown 308 inflight 241 sec
[ 1293.502525] page_pool_release_retry() stalled pool shutdown 86 inflight 483 sec
[ 1338.110518] page_pool_release_retry() stalled pool shutdown 308 inflight 302 sec
[ 1353.918540] page_pool_release_retry() stalled pool shutdown 32 inflight 543 sec
[ 1361.179205] Qualcomm Atheros AR8031/AR8033 30be0000.ethernet-1:00: attached PHY driver (mii_bus:phy_addr=30be0000.ethernet-1:00, irq=POLL)
[ 1364.255298] fec 30be0000.ethernet eth0: Link is Up - 1Gbps/Full - flow control rx/tx
[ 1364.263189] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
[ 1371.998532] page_pool_release_retry() stalled pool shutdown 310 inflight 60 sec
[ 1398.530542] page_pool_release_retry() stalled pool shutdown 308 inflight 362 sec
[ 1414.334539] page_pool_release_retry() stalled pool shutdown 16 inflight 604 sec
[ 1432.414520] page_pool_release_retry() stalled pool shutdown 310 inflight 120 sec
[ 1458.942523] page_pool_release_retry() stalled pool shutdown 308 inflight 422 sec
[ 1474.750521] page_pool_release_retry() stalled pool shutdown 16 inflight 664 sec
TINFO:ENET  up and down test 394 times
[ 1492.830522] page_pool_release_retry() stalled pool shutdown 310 inflight 181 sec
[ 1519.358519] page_pool_release_retry() stalled pool shutdown 308 inflight 483 sec
[ 1535.166545] page_pool_release_retry() stalled pool shutdown 2 inflight 724 sec
[ 1537.090278] eth_test2.sh invoked oom-killer: gfp_mask=0x400dc0(GFP_KERNEL_ACCOUNT|__GFP_ZERO), order=0, oom_score_adj=0
[ 1537.101192] CPU: 3 PID: 2379 Comm: eth_test2.sh Tainted: G         C         6.1.1+g56321e101aca #1
[ 1537.110249] Hardware name: NXP i.MX8MNano EVK board (DT)
[ 1537.115561] Call trace:
[ 1537.118005]  dump_backtrace.part.0+0xe0/0xf0
[ 1537.122289]  show_stack+0x18/0x40
[ 1537.125608]  dump_stack_lvl+0x64/0x80
[ 1537.129276]  dump_stack+0x18/0x34
[ 1537.132592]  dump_header+0x44/0x208
[ 1537.136083]  oom_kill_process+0x2b4/0x2c0
[ 1537.140097]  out_of_memory+0xe4/0x594
[ 1537.143766]  __alloc_pages+0xb68/0xd00
[ 1537.147521]  alloc_pages+0xac/0x160
[ 1537.151013]  __get_free_pages+0x14/0x40
[ 1537.154851]  pgd_alloc+0x1c/0x30
[ 1537.158082]  mm_init+0xf8/0x1d0
[ 1537.161228]  mm_alloc+0x48/0x60
[ 1537.164368]  alloc_bprm+0x7c/0x240
[ 1537.167777]  do_execveat_common.isra.0+0x70/0x240
[ 1537.172486]  __arm64_sys_execve+0x40/0x54
[ 1537.176502]  invoke_syscall+0x48/0x114
[ 1537.180255]  el0_svc_common.constprop.0+0xcc/0xec
[ 1537.184964]  do_el0_svc+0x2c/0xd0
[ 1537.188280]  el0_svc+0x2c/0x84
[ 1537.191340]  el0t_64_sync_handler+0xf4/0x120
[ 1537.195613]  el0t_64_sync+0x18c/0x190
[ 1537.199334] Mem-Info:
[ 1537.201620] active_anon:342 inactive_anon:10343 isolated_anon:0
[ 1537.201620]  active_file:54 inactive_file:112 isolated_file:0
[ 1537.201620]  unevictable:0 dirty:0 writeback:0
[ 1537.201620]  slab_reclaimable:2620 slab_unreclaimable:7076
[ 1537.201620]  mapped:1489 shmem:2473 pagetables:466
[ 1537.201620]  sec_pagetables:0 bounce:0
[ 1537.201620]  kernel_misc_reclaimable:0
[ 1537.201620]  free:136672 free_pcp:96 free_cma:129241
[ 1537.240419] Node 0 active_anon:1368kB inactive_anon:41372kB active_file:216kB inactive_file:5052kB unevictable:0kB isolated(anon):0kB isolated(file):0kB s
[ 1537.271422] Node 0 DMA free:541636kB boost:0kB min:30000kB low:37500kB high:45000kB reserved_highatomic:0KB active_anon:1368kB inactive_anon:41372kB actiB
[ 1537.300219] lowmem_reserve[]: 0 0 0 0
[ 1537.303929] Node 0 DMA: 1015*4kB (UMEC) 743*8kB (UMEC) 417*16kB (UMEC) 235*32kB (UMEC) 116*64kB (UMEC) 25*128kB (UMEC) 4*256kB (UC) 2*512kB (UC) 0*1024kBB
[ 1537.323938] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=1048576kB
[ 1537.332708] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=32768kB
[ 1537.341292] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=2048kB
[ 1537.349776] Node 0 hugepages_total=0 hugepages_free=0 hugepages_surp=0 hugepages_size=64kB
[ 1537.358087] 2939 total pagecache pages
[ 1537.361876] 0 pages in swap cache
[ 1537.365229] Free swap  = 0kB
[ 1537.368147] Total swap = 0kB
[ 1537.371065] 516096 pages RAM
[ 1537.373959] 0 pages HighMem/MovableOnly
[ 1537.377834] 17302 pages reserved
[ 1537.381103] 163840 pages cma reserved
[ 1537.384809] 0 pages hwpoisoned
[ 1537.387902] Tasks state (memory values in pages):
[ 1537.392652] [  pid  ]   uid  tgid total_vm      rss pgtables_bytes swapents oom_score_adj name
[ 1537.401356] [    201]   993   201     1130       72    45056        0             0 rpcbind
[ 1537.409772] [    202]     0   202     4529     1640    77824        0          -250 systemd-journal
[ 1537.418861] [    222]     0   222     4691      801    69632        0         -1000 systemd-udevd
[ 1537.427787] [    248]   994   248    20914      130    65536        0             0 systemd-timesyn
[ 1537.436884] [    497]     0   497      620       31    49152        0             0 atd
[ 1537.444938] [    500]     0   500      854       77    53248        0             0 crond
[ 1537.453165] [    503]   997   503     1470      160    49152        0          -900 dbus-daemon
[ 1537.461908] [    505]     0   505      633       24    40960        0             0 firmwared
[ 1537.470491] [    513]     0   513     2507      180    61440        0             0 ofonod
[ 1537.478800] [    514]   990   514    69640      137    81920        0             0 parsec
[ 1537.487120] [    533]     0   533      599       39    40960        0             0 syslogd
[ 1537.495518] [    534]     0   534     4546      148    65536        0             0 systemd-logind
[ 1537.504560] [    535]     0   535      690       24    45056        0             0 tee-supplicant
[ 1537.513564] [    540]   996   540     2769      168    61440        0             0 systemd-network
[ 1537.522680] [    566]     0   566     3878      228    77824        0             0 connmand
[ 1537.531168] [    645]   998   645     1538      133    57344        0             0 avahi-daemon
[ 1537.540004] [    646]   998   646     1461       64    57344        0             0 avahi-daemon
[ 1537.548846] [    648]   992   648      781       41    45056        0             0 rpc.statd
[ 1537.557415] [    650] 64371   650      590       23    45056        0             0 ninfod
[ 1537.565754] [    653] 61563   653      555       24    45056        0             0 rdisc
[ 1537.573971] [    655]     0   655   374569     2999   290816        0          -999 containerd
[ 1537.582621] [    658]     0   658     1311       20    49152        0             0 agetty
[ 1537.590922] [    663]     0   663     1529       97    49152        0             0 login
[ 1537.599138] [    666]     0   666     3430      202    69632        0             0 wpa_supplicant
[ 1537.608147] [    667]     0   667     2344       96    61440        0             0 systemd-userdbd
[ 1537.617240] [    677]     0   677     2964      314    65536        0           100 systemd
[ 1537.625651] [    679]     0   679     3720      646    73728        0           100 (sd-pam)
[ 1537.634138] [    687]     0   687     1289      403    45056        0             0 sh
[ 1537.642108] [    789]     0   789      970       93    45056        0             0 eth_test2.sh
[ 1537.650955] [   2355]     0  2355     2346       94    61440        0             0 systemd-userwor
[ 1537.660046] [   2356]     0  2356     2346       94    61440        0             0 systemd-userwor
[ 1537.669137] [   2358]     0  2358     2346       95    57344        0             0 systemd-userwor
[ 1537.678258] [   2379]     0  2379      970       93    45056        0             0 eth_test2.sh
[ 1537.687098] oom-kill:constraint=CONSTRAINT_NONE,nodemask=(null),cpuset=/,mems_allowed=0,global_oom,task_memcg=/user.slice/user-0.slice/[email protected],tas0
[ 1537.703009] Out of memory: Killed process 679 ((sd-pam)) total-vm:14880kB, anon-rss:2584kB, file-rss:0kB, shmem-rss:0kB, UID:0 pgtables:72kB oom_score_ad0
[ 1553.246526] page_pool_release_retry() stalled pool shutdown 310 inflight 241 sec

Fixes: 95698ff ("net: fec: using page pool to manage RX buffers")
Signed-off-by: Wei Fang <[email protected]>
Reviewed-by: shenwei wang <[email protected]>
Reviewed-by: Jesse Brandeburg <[email protected]>
Signed-off-by: David S. Miller <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
Jakub Sitnicki says:

====================

This patch set addresses the syzbot report in [1].

Patch #1 has been suggested by Eric [2]. I extended it to cover the rest of
sock_map proto callbacks. Otherwise we would still overflow the stack.

Patch #2 contains the actual fix and bug analysis.
Patches #3 & #4 add coverage to selftests to trigger the bug.

[1] https://lore.kernel.org/all/[email protected]/
[2] https://lore.kernel.org/all/CANn89iK2UN1FmdUcH12fv_xiZkv2G+Nskvmq7fG6aA_6VKRf6g@mail.gmail.com/
---
v1 -> v2:
v1: https://lore.kernel.org/r/[email protected]
[v1 didn't hit bpf@ ML by mistake]

 * pull in Eric's patch to protect against recursion loop bugs (Eric)
 * add a macro helper to check if pointer is inside a memory range (Eric)
====================

Signed-off-by: Alexei Starovoitov <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
Set kprobe at 'jalr 1140(ra)' of vfs_write results in the following
crash:

[   32.092235] Unable to handle kernel access to user memory without uaccess routines at virtual address 00aaaaaad77b1170
[   32.093115] Oops [#1]
[   32.093251] Modules linked in:
[   32.093626] CPU: 0 PID: 135 Comm: ftracetest Not tainted 6.2.0-rc2-00013-gb0aa5e5df0cb-dirty torvalds#16
[   32.093985] Hardware name: riscv-virtio,qemu (DT)
[   32.094280] epc : ksys_read+0x88/0xd6
[   32.094855]  ra : ksys_read+0xc0/0xd6
[   32.095016] epc : ffffffff801cda80 ra : ffffffff801cdab8 sp : ff20000000d7bdc0
[   32.095227]  gp : ffffffff80f14000 tp : ff60000080f9cb40 t0 : ffffffff80f13e80
[   32.095500]  t1 : ffffffff8000c29c t2 : ffffffff800dbc54 s0 : ff20000000d7be60
[   32.095716]  s1 : 0000000000000000 a0 : ffffffff805a64ae a1 : ffffffff80a83708
[   32.095921]  a2 : ffffffff80f160a0 a3 : 0000000000000000 a4 : f229b0afdb165300
[   32.096171]  a5 : f229b0afdb165300 a6 : ffffffff80eeebd0 a7 : 00000000000003ff
[   32.096411]  s2 : ff6000007ff76800 s3 : fffffffffffffff7 s4 : 00aaaaaad77b1170
[   32.096638]  s5 : ffffffff80f160a0 s6 : ff6000007ff76800 s7 : 0000000000000030
[   32.096865]  s8 : 00ffffffc3d97be0 s9 : 0000000000000007 s10: 00aaaaaad77c9410
[   32.097092]  s11: 0000000000000000 t3 : ffffffff80f13e48 t4 : ffffffff8000c29c
[   32.097317]  t5 : ffffffff8000c29c t6 : ffffffff800dbc54
[   32.097505] status: 0000000200000120 badaddr: 00aaaaaad77b1170 cause: 000000000000000d
[   32.098011] [<ffffffff801cdb72>] ksys_write+0x6c/0xd6
[   32.098222] [<ffffffff801cdc06>] sys_write+0x2a/0x38
[   32.098405] [<ffffffff80003c76>] ret_from_syscall+0x0/0x2

Since the rs1 and rd might be the same one, such as 'jalr 1140(ra)',
hence it requires obtaining the target address from rs1 followed by
updating rd.

Fixes: c22b0bc ("riscv: Add kprobes supported")
Signed-off-by: Liao Chang <[email protected]>
Reviewed-by: Guo Ren <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
[Palmer: Pick Guo's cleanup]
Signed-off-by: Palmer Dabbelt <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
…lume

The freeing of relinquished volume will wake up the pending volume
acquisition by using wake_up_bit(), however it is mismatched with
wait_var_event() used in fscache_wait_on_volume_collision() and it will
never wake up the waiter in the wait-queue because these two functions
operate on different wait-queues.

According to the implementation in fscache_wait_on_volume_collision(),
if the wake-up of pending acquisition is delayed longer than 20 seconds
(e.g., due to the delay of on-demand fd closing), the first
wait_var_event_timeout() will timeout and the following wait_var_event()
will hang forever as shown below:

 FS-Cache: Potential volume collision new=00000024 old=00000022
 ......
 INFO: task mount:1148 blocked for more than 122 seconds.
       Not tainted 6.1.0-rc6+ #1
 task:mount           state:D stack:0     pid:1148  ppid:1
 Call Trace:
  <TASK>
  __schedule+0x2f6/0xb80
  schedule+0x67/0xe0
  fscache_wait_on_volume_collision.cold+0x80/0x82
  __fscache_acquire_volume+0x40d/0x4e0
  erofs_fscache_register_volume+0x51/0xe0 [erofs]
  erofs_fscache_register_fs+0x19c/0x240 [erofs]
  erofs_fc_fill_super+0x746/0xaf0 [erofs]
  vfs_get_super+0x7d/0x100
  get_tree_nodev+0x16/0x20
  erofs_fc_get_tree+0x20/0x30 [erofs]
  vfs_get_tree+0x24/0xb0
  path_mount+0x2fa/0xa90
  do_mount+0x7c/0xa0
  __x64_sys_mount+0x8b/0xe0
  do_syscall_64+0x30/0x60
  entry_SYSCALL_64_after_hwframe+0x46/0xb0

Considering that wake_up_bit() is more selective, so fix it by using
wait_on_bit() instead of wait_var_event() to wait for the freeing of
relinquished volume. In addition because waitqueue_active() is used in
wake_up_bit() and clear_bit() doesn't imply any memory barrier, use
clear_and_wake_up_bit() to add the missing memory barrier between
cursor->flags and waitqueue_active().

Fixes: 62ab633 ("fscache: Implement volume registration")
Reviewed-by: Jingbo Xu <[email protected]>
Signed-off-by: Hou Tao <[email protected]>
Signed-off-by: David Howells <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Link: https://lore.kernel.org/r/[email protected]/ # v3
planetA pushed a commit that referenced this issue Feb 10, 2023
The recent commit 76d588d ("powerpc/imc-pmu: Fix use of mutex in
IRQs disabled section") fixed warnings (and possible deadlocks) in the
IMC PMU driver by converting the locking to use spinlocks.

It also converted the init-time nest_init_lock to a spinlock, even
though it's not used at runtime in IRQ disabled sections or while
holding other spinlocks.

This leads to warnings such as:

  BUG: sleeping function called from invalid context at include/linux/percpu-rwsem.h:49
  in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 1, name: swapper/0
  preempt_count: 1, expected: 0
  CPU: 7 PID: 1 Comm: swapper/0 Not tainted 6.2.0-rc2-14719-gf12cd06109f4-dirty #1
  Hardware name: Mambo,Simulated-System POWER9 0x4e1203 opal:v6.6.6 PowerNV
  Call Trace:
    dump_stack_lvl+0x74/0xa8 (unreliable)
    __might_resched+0x178/0x1a0
    __cpuhp_setup_state+0x64/0x1e0
    init_imc_pmu+0xe48/0x1250
    opal_imc_counters_probe+0x30c/0x6a0
    platform_probe+0x78/0x110
    really_probe+0x104/0x420
    __driver_probe_device+0xb0/0x170
    driver_probe_device+0x58/0x180
    __driver_attach+0xd8/0x250
    bus_for_each_dev+0xb4/0x140
    driver_attach+0x34/0x50
    bus_add_driver+0x1e8/0x2d0
    driver_register+0xb4/0x1c0
    __platform_driver_register+0x38/0x50
    opal_imc_driver_init+0x2c/0x40
    do_one_initcall+0x80/0x360
    kernel_init_freeable+0x310/0x3b8
    kernel_init+0x30/0x1a0
    ret_from_kernel_thread+0x5c/0x64

Fix it by converting nest_init_lock back to a mutex, so that we can call
sleeping functions while holding it. There is no interaction between
nest_init_lock and the runtime spinlocks used by the actual PMU routines.

Fixes: 76d588d ("powerpc/imc-pmu: Fix use of mutex in IRQs disabled section")
Tested-by: Kajol Jain<[email protected]>
Reviewed-by: Kajol Jain<[email protected]>
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
planetA pushed a commit that referenced this issue Feb 10, 2023
If a relocatable kernel is loaded at an address that is not 2MB aligned
and told not to relocate to zero, the kernel can crash due to
mark_rodata_ro() incorrectly changing some read-write data to read-only.

Scenarios where the misalignment can occur are when the kernel is
loaded by kdump or using the RELOCATABLE_TEST config option.

Example crash with the kernel loaded at 5MB:

  Run /sbin/init as init process
  BUG: Unable to handle kernel data access on write at 0xc000000000452000
  Faulting instruction address: 0xc0000000005b6730
  Oops: Kernel access of bad area, sig: 11 [#1]
  LE PAGE_SIZE=64K MMU=Radix SMP NR_CPUS=2048 NUMA pSeries
  CPU: 1 PID: 1 Comm: init Not tainted 6.2.0-rc1-00011-g349188be4841 torvalds#166
  Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1202 0xf000005 of:SLOF,git-5b4c5a hv:linux,kvm pSeries
  NIP:  c0000000005b6730 LR: c000000000ae9ab8 CTR: 0000000000000380
  REGS: c000000004503250 TRAP: 0300   Not tainted  (6.2.0-rc1-00011-g349188be4841)
  MSR:  8000000000009033 <SF,EE,ME,IR,DR,RI,LE>  CR: 44288480  XER: 00000000
  CFAR: c0000000005b66ec DAR: c000000000452000 DSISR: 0a000000 IRQMASK: 0
  ...
  NIP memset+0x68/0x104
  LR  zero_user_segments.constprop.0+0xa8/0xf0
  Call Trace:
    ext4_mpage_readpages+0x7f8/0x830
    ext4_readahead+0x48/0x60
    read_pages+0xb8/0x380
    page_cache_ra_unbounded+0x19c/0x250
    filemap_fault+0x58c/0xae0
    __do_fault+0x60/0x100
    __handle_mm_fault+0x1230/0x1a40
    handle_mm_fault+0x120/0x300
    ___do_page_fault+0x20c/0xa80
    do_page_fault+0x30/0xc0
    data_access_common_virt+0x210/0x220

This happens because mark_rodata_ro() tries to change permissions on the
range _stext..__end_rodata, but _stext sits in the middle of the 2MB
page from 4MB to 6MB:

  radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
  radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
  radix-mmu: Mapped 0x0000000000400000-0x0000000002400000 with 2.00 MiB pages (exec)

The logic that changes the permissions assumes the linear mapping was
split correctly at boot, so it marks the entire 2MB page read-only. That
leads to the write fault above.

To fix it, the boot time mapping logic needs to consider that if the
kernel is running at a non-zero address then _stext is a boundary where
it must split the mapping.

That leads to the mapping being split correctly, allowing the rodata
permission change to take happen correctly, with no spillover:

  radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
  radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
  radix-mmu: Mapped 0x0000000000400000-0x0000000000500000 with 64.0 KiB pages
  radix-mmu: Mapped 0x0000000000500000-0x0000000000600000 with 64.0 KiB pages (exec)
  radix-mmu: Mapped 0x0000000000600000-0x0000000002400000 with 2.00 MiB pages (exec)

If the kernel is loaded at a 2MB aligned address, the mapping continues
to use 2MB pages as before:

  radix-mmu: Mapped 0x0000000000000000-0x0000000000200000 with 2.00 MiB pages (exec)
  radix-mmu: Mapped 0x0000000000200000-0x0000000000400000 with 2.00 MiB pages
  radix-mmu: Mapped 0x0000000000400000-0x0000000002c00000 with 2.00 MiB pages (exec)
  radix-mmu: Mapped 0x0000000002c00000-0x0000000100000000 with 2.00 MiB pages

Fixes: c55d7b5 ("powerpc: Remove STRICT_KERNEL_RWX incompatibility with RELOCATABLE")
Signed-off-by: Michael Ellerman <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
planetA pushed a commit that referenced this issue Feb 10, 2023
… UAF

After a call to console_unlock() in vcs_read() the vc_data struct can be
freed by vc_deallocate(). Because of that, the struct vc_data pointer
load must be done at the top of while loop in vcs_read() to avoid a UAF
when vcs_size() is called.

Syzkaller reported a UAF in vcs_size().

BUG: KASAN: use-after-free in vcs_size (drivers/tty/vt/vc_screen.c:215)
Read of size 4 at addr ffff8881137479a8 by task 4a005ed81e27e65/1537

CPU: 0 PID: 1537 Comm: 4a005ed81e27e65 Not tainted 6.2.0-rc5 #1
Hardware name: Red Hat KVM, BIOS 1.15.0-2.module
Call Trace:
  <TASK>
__asan_report_load4_noabort (mm/kasan/report_generic.c:350)
vcs_size (drivers/tty/vt/vc_screen.c:215)
vcs_read (drivers/tty/vt/vc_screen.c:415)
vfs_read (fs/read_write.c:468 fs/read_write.c:450)
...
  </TASK>

Allocated by task 1191:
...
kmalloc_trace (mm/slab_common.c:1069)
vc_allocate (./include/linux/slab.h:580 ./include/linux/slab.h:720
     drivers/tty/vt/vt.c:1128 drivers/tty/vt/vt.c:1108)
con_install (drivers/tty/vt/vt.c:3383)
tty_init_dev (drivers/tty/tty_io.c:1301 drivers/tty/tty_io.c:1413
     drivers/tty/tty_io.c:1390)
tty_open (drivers/tty/tty_io.c:2080 drivers/tty/tty_io.c:2126)
chrdev_open (fs/char_dev.c:415)
do_dentry_open (fs/open.c:883)
vfs_open (fs/open.c:1014)
...

Freed by task 1548:
...
kfree (mm/slab_common.c:1021)
vc_port_destruct (drivers/tty/vt/vt.c:1094)
tty_port_destructor (drivers/tty/tty_port.c:296)
tty_port_put (drivers/tty/tty_port.c:312)
vt_disallocate_all (drivers/tty/vt/vt_ioctl.c:662 (discriminator 2))
vt_ioctl (drivers/tty/vt/vt_ioctl.c:903)
tty_ioctl (drivers/tty/tty_io.c:2776)
...

The buggy address belongs to the object at ffff888113747800
  which belongs to the cache kmalloc-1k of size 1024
The buggy address is located 424 bytes inside of
  1024-byte region [ffff888113747800, ffff888113747c00)

The buggy address belongs to the physical page:
page:00000000b3fe6c7c refcount:1 mapcount:0 mapping:0000000000000000
     index:0x0 pfn:0x113740
head:00000000b3fe6c7c order:3 compound_mapcount:0 subpages_mapcount:0
     compound_pincount:0
anon flags: 0x17ffffc0010200(slab|head|node=0|zone=2|lastcpupid=0x1fffff)
raw: 0017ffffc0010200 ffff888100042dc0 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff888113747880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff888113747900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff888113747980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                   ^
  ffff888113747a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff888113747a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
Disabling lock debugging due to kernel taint

Fixes: ac751ef ("console: rename acquire/release_console_sem() to console_lock/unlock()")
Reported-by: syzkaller <[email protected]>
Suggested-by: Jiri Slaby <[email protected]>
Signed-off-by: George Kennedy <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Greg Kroah-Hartman <[email protected]>
planetA pushed a commit that referenced this issue Feb 10, 2023
NVMe In-Band authentication uses two kinds of works: chap->auth_work and
ctrl->dhchap_auth_work. The latter work flushes or cancels the former
work. However, the both works are queued to the same workqueue nvme-wq.
It results in the lockdep WARNING as follows:

 WARNING: possible recursive locking detected
 6.2.0-rc4+ #1 Not tainted
 --------------------------------------------
 kworker/u16:7/69 is trying to acquire lock:
 ffff902d52e65548 ((wq_completion)nvme-wq){+.+.}-{0:0}, at: start_flush_work+0x2c5/0x380

 but task is already holding lock:
 ffff902d52e65548 ((wq_completion)nvme-wq){+.+.}-{0:0}, at: process_one_work+0x210/0x410

To avoid the WARNING, introduce a new workqueue nvme-auth-wq dedicated
to chap->auth_work.

Reported-by: Daniel Wagner <[email protected]>
Link: https://lore.kernel.org/linux-nvme/[email protected]/
Fixes: f50fff7 ("nvme: implement In-Band authentication")
Signed-off-by: Shin'ichiro Kawasaki <[email protected]>
Tested-by: Daniel Wagner <[email protected]>
Reviewed-by: Hannes Reinecke <[email protected]>
Signed-off-by: Christoph Hellwig <[email protected]>
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