diff options
| author | Logan Gunthorpe <logang@deltatee.com> | 2022-06-08 10:27:52 -0600 |
|---|---|---|
| committer | Song Liu <song@kernel.org> | 2022-07-03 07:55:37 -0700 |
| commit | 0d79ac61090f92f8e94d459715b2fa2cd5c14199 (patch) | |
| tree | 10b858f3261554e16fed0c9d3c0843501240f149 /drivers/md/raid5-cache.c | |
| parent | 33fa9f7c08f7e2258f117a21a4c0bfc5bc146e20 (diff) | |
md/raid5-cache: Clear conf->log after finishing work
A NULL pointer dereferlence on conf->log is seen randomly with
the mdadm test 21raid5cache. Kasan reporst:
BUG: KASAN: null-ptr-deref in r5l_reclaimable_space+0xf5/0x140
Read of size 8 at addr 0000000000000860 by task md0_reclaim/3086
Call Trace:
dump_stack_lvl+0x5a/0x74
kasan_report.cold+0x5f/0x1a9
__asan_load8+0x69/0x90
r5l_reclaimable_space+0xf5/0x140
r5l_do_reclaim+0xf4/0x5e0
r5l_reclaim_thread+0x69/0x3b0
md_thread+0x1a2/0x2c0
kthread+0x177/0x1b0
ret_from_fork+0x22/0x30
This is caused by conf->log being cleared in r5l_exit_log() before
stopping the reclaim thread.
To fix this, clear conf->log after the reclaim_thread is unregistered
and after flushing disable_writeback_work.
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Song Liu <song@kernel.org>
Diffstat (limited to 'drivers/md/raid5-cache.c')
| -rw-r--r-- | drivers/md/raid5-cache.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/drivers/md/raid5-cache.c b/drivers/md/raid5-cache.c index b1fc65e113f8..ca57b5fac599 100644 --- a/drivers/md/raid5-cache.c +++ b/drivers/md/raid5-cache.c @@ -3165,12 +3165,13 @@ void r5l_exit_log(struct r5conf *conf) { struct r5l_log *log = conf->log; - conf->log = NULL; - /* Ensure disable_writeback_work wakes up and exits */ wake_up(&conf->mddev->sb_wait); flush_work(&log->disable_writeback_work); md_unregister_thread(&log->reclaim_thread); + + conf->log = NULL; + mempool_exit(&log->meta_pool); bioset_exit(&log->bs); mempool_exit(&log->io_pool); |