From: Jan Kara
mainline inclusion
from mainline-v5.12-rc4
commit 2a4ae3bcdf05b8639406eaa09a2939f3c6dd8e75
category: bugfix
issue: #I3ZXZF
CVE: NA
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
-----------------------------------------------
When filesystem mount fails because of corrupted filesystem we first
cancel the s_err_report timer reminding fs errors every day and only
then we flush s_error_work. However s_error_work may report another fs
error and re-arm timer thus resulting in timer use-after-free. Fix the
problem by first flushing the work and only after that canceling the
s_err_report timer.
Reported-by: syzbot+628472a2aac693ab0fcd@syzkaller.appspotmail.com
Fixes: 2d01ddc86606 ("ext4: save error info to sb through journal if available")
CC: stable@vger.kernel.org
Signed-off-by: Jan Kara
Link: https://lore.kernel.org/r/20210315165906.2175-1-jack@suse.cz
Signed-off-by: Theodore Ts'o
Signed-off-by: Ye Bin
Reviewed-by: zhangyi (F)
Signed-off-by: Chen Jun
Signed-off-by: Yu Changchun
---
fs/ext4/super.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 713a2f210966..18b724390a74 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -5148,8 +5148,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
failed_mount3a:
ext4_es_unregister_shrinker(sbi);
failed_mount3:
- del_timer_sync(&sbi->s_err_report);
flush_work(&sbi->s_error_work);
+ del_timer_sync(&sbi->s_err_report);
if (sbi->s_mmp_tsk)
kthread_stop(sbi->s_mmp_tsk);
failed_mount2:
--
2.22.0
