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| author | Dave Wysochanski <dwysocha@redhat.com> | 2021-10-03 12:14:00 -0400 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2021-10-05 11:22:06 +0100 |
| commit | a0e25f0a0d39d66c048d5dbac1e7ebaa6ec885d7 (patch) | |
| tree | 603b7db641c1aac17c21c1e0dfbf39854b4c2360 /include | |
| parent | 9e1ff307c779ce1f0f810c7ecce3d95bbae40896 (diff) | |
| download | linux-a0e25f0a0d39d66c048d5dbac1e7ebaa6ec885d7.tar.gz | |
cachefiles: Fix oops with cachefiles_cull() due to NULL object
When cachefiles_cull() calls cachefiles_bury_object(), it passes
a NULL object. When this occurs, either trace_cachefiles_unlink()
or trace_cachefiles_rename() may oops due to the NULL object.
Check for NULL object in the tracepoint and if so, set debug_id
to MAX_UINT as was done in 2908f5e101e3.
The following oops was seen with xfstests generic/100.
BUG: kernel NULL pointer dereference, address: 0000000000000010
...
RIP: 0010:trace_event_raw_event_cachefiles_unlink+0x4e/0xa0 [cachefiles]
...
Call Trace:
cachefiles_bury_object+0x242/0x430 [cachefiles]
? __vfs_removexattr_locked+0x10f/0x150
? vfs_removexattr+0x51/0xd0
cachefiles_cull+0x84/0x120 [cachefiles]
cachefiles_daemon_cull+0xd1/0x120 [cachefiles]
cachefiles_daemon_write+0x158/0x190 [cachefiles]
vfs_write+0xbc/0x260
ksys_write+0x4f/0xc0
do_syscall_64+0x3b/0x90
The following oops was seen with xfstests generic/290.
BUG: kernel NULL pointer dereference, address: 0000000000000010
...
RIP: 0010:trace_event_raw_event_cachefiles_rename+0x54/0xa0 [cachefiles]
...
Call Trace:
cachefiles_bury_object+0x35c/0x430 [cachefiles]
cachefiles_cull+0x84/0x120 [cachefiles]
cachefiles_daemon_cull+0xd1/0x120 [cachefiles]
cachefiles_daemon_write+0x158/0x190 [cachefiles]
vfs_write+0xbc/0x260
ksys_write+0x4f/0xc0
do_syscall_64+0x3b/0x90
Fixes: 2908f5e101e3 ("fscache: Add a cookie debug ID and use that in traces")
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Link: https://listman.redhat.com/archives/linux-cachefs/2021-October/msg00009.html
Diffstat (limited to 'include')
| -rw-r--r-- | include/trace/events/cachefiles.h | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h index 695bfdbfdcad..920b6a303d60 100644 --- a/include/trace/events/cachefiles.h +++ b/include/trace/events/cachefiles.h @@ -178,7 +178,7 @@ TRACE_EVENT(cachefiles_unlink, ), TP_fast_assign( - __entry->obj = obj->fscache.debug_id; + __entry->obj = obj ? obj->fscache.debug_id : UINT_MAX; __entry->de = de; __entry->why = why; ), @@ -205,7 +205,7 @@ TRACE_EVENT(cachefiles_rename, ), TP_fast_assign( - __entry->obj = obj->fscache.debug_id; + __entry->obj = obj ? obj->fscache.debug_id : UINT_MAX; __entry->de = de; __entry->to = to; __entry->why = why; |