libselinux: set free'd data to NULL

Fixes segfault in selabel_open() on systems with SELinux disabled and without any SELinux policy installed introduced by commit 5876aca ("libselinux: free data on selabel open failure"): $ sestatus SELinux status: disabled $ cat /etc/selinux/config cat: /etc/selinux/config: No such file or directory $ matchpathcon /abc [1] 907999 segmentation fault (core dumped) matchpathcon /abc Signed-off-by: Petr Lautrbach <[email protected]> Acked-by: James Carter <[email protected]>
SELinuxProject · Jul 22, 2024 · f398662 · f398662
1 parent 2eb286b
commit f398662
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diff --git a/libselinux/src/label_backends_android.c b/libselinux/src/label_backends_android.c
@@ -260,6 +260,7 @@ static void closef(struct selabel_handle *rec)
 		free(data->spec_arr);
 
 	free(data);
+	rec->data = NULL;
 }
 
 static struct selabel_lookup_rec *property_lookup(struct selabel_handle *rec,

diff --git a/libselinux/src/label_file.c b/libselinux/src/label_file.c
@@ -942,6 +942,7 @@ static void closef(struct selabel_handle *rec)
 		free(last_area);
 	}
 	free(data);
+	rec->data = NULL;
 }
 
 // Finds all the matches of |key| in the given context. Returns the result in

diff --git a/libselinux/src/label_media.c b/libselinux/src/label_media.c
@@ -183,6 +183,7 @@ static void close(struct selabel_handle *rec)
 	    free(spec_arr);
 
 	free(data);
+	rec->data = NULL;
 }
 
 static struct selabel_lookup_rec *lookup(struct selabel_handle *rec,

diff --git a/libselinux/src/label_x.c b/libselinux/src/label_x.c
@@ -210,6 +210,7 @@ static void close(struct selabel_handle *rec)
 	    free(spec_arr);
 
 	free(data);
+	rec->data = NULL;
 }
 
 static struct selabel_lookup_rec *lookup(struct selabel_handle *rec,