From 0e435befaea45f7ea58682eecab5e37e05b2ce65 Mon Sep 17 00:00:00 2001 From: Lijun Pan Date: Mon, 23 Nov 2020 13:35:46 -0600 Subject: [PATCH] ibmvnic: fix NULL pointer dereference in ibmvic_reset_crq crq->msgs could be NULL if the previous reset did not complete after freeing crq->msgs. Check for NULL before dereferencing them. Snippet of call trace: ... ibmvnic 30000003 env3 (unregistering): Releasing sub-CRQ ibmvnic 30000003 env3 (unregistering): Releasing CRQ BUG: Kernel NULL pointer dereference on read at 0x00000000 Faulting instruction address: 0xc0000000000c1a30 Oops: Kernel access of bad area, sig: 11 [#1] LE PAGE_SIZE=64K MMU=Hash SMP NR_CPUS=2048 NUMA pSeries Modules linked in: ibmvnic(E-) rpadlpar_io rpaphp xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 nft_compat nft_counter nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables xsk_diag tcp_diag udp_diag tun raw_diag inet_diag unix_diag bridge af_packet_diag netlink_diag stp llc rfkill sunrpc pseries_rng xts vmx_crypto uio_pdrv_genirq uio binfmt_misc ip_tables xfs libcrc32c sd_mod t10_pi sg ibmvscsi ibmveth scsi_transport_srp dm_mirror dm_region_hash dm_log dm_mod [last unloaded: ibmvnic] CPU: 20 PID: 8426 Comm: kworker/20:0 Tainted: G E 5.10.0-rc1+ #12 Workqueue: events __ibmvnic_reset [ibmvnic] NIP: c0000000000c1a30 LR: c008000001b00c18 CTR: 0000000000000400 REGS: c00000000d05b7a0 TRAP: 0380 Tainted: G E (5.10.0-rc1+) MSR: 800000000280b033 CR: 44002480 XER: 20040000 CFAR: c0000000000c19ec IRQMASK: 0 GPR00: 0000000000000400 c00000000d05ba30 c008000001b17c00 0000000000000000 GPR04: 0000000000000000 0000000000000000 0000000000000000 00000000000001e2 GPR08: 000000000001f400 ffffffffffffd950 0000000000000000 c008000001b0b280 GPR12: c0000000000c19c8 c00000001ec72e00 c00000000019a778 c00000002647b440 GPR16: 0000000000000000 0000000000000000 0000000000000000 0000000000000000 GPR20: 0000000000000006 0000000000000001 0000000000000003 0000000000000002 GPR24: 0000000000001000 c008000001b0d570 0000000000000005 c00000007ab5d550 GPR28: c00000007ab5c000 c000000032fcf848 c00000007ab5cc00 c000000032fcf800 NIP [c0000000000c1a30] memset+0x68/0x104 LR [c008000001b00c18] ibmvnic_reset_crq+0x70/0x110 [ibmvnic] Call Trace: [c00000000d05ba30] [0000000000000800] 0x800 (unreliable) [c00000000d05bab0] [c008000001b0a930] do_reset.isra.40+0x224/0x634 [ibmvnic] [c00000000d05bb80] [c008000001b08574] __ibmvnic_reset+0x17c/0x3c0 [ibmvnic] [c00000000d05bc50] [c00000000018d9ac] process_one_work+0x2cc/0x800 [c00000000d05bd20] [c00000000018df58] worker_thread+0x78/0x520 [c00000000d05bdb0] [c00000000019a934] kthread+0x1c4/0x1d0 [c00000000d05be20] [c00000000000d5d0] ret_from_kernel_thread+0x5c/0x6c Fixes: 032c5e82847a ("Driver for IBM System i/p VNIC protocol") Signed-off-by: Lijun Pan Signed-off-by: Jakub Kicinski --- drivers/net/ethernet/ibm/ibmvnic.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/net/ethernet/ibm/ibmvnic.c b/drivers/net/ethernet/ibm/ibmvnic.c index db4a8e17477c01..26ba07df404ef2 100644 --- a/drivers/net/ethernet/ibm/ibmvnic.c +++ b/drivers/net/ethernet/ibm/ibmvnic.c @@ -4973,6 +4973,9 @@ static int ibmvnic_reset_crq(struct ibmvnic_adapter *adapter) } while (rc == H_BUSY || H_IS_LONG_BUSY(rc)); /* Clean out the queue */ + if (!crq->msgs) + return -EINVAL; + memset(crq->msgs, 0, PAGE_SIZE); crq->cur = 0; crq->active = false;