From: Li Guifu <[email protected]>
During umount, f2fs_put_super() unregisters procfs entries after
f2fs_destroy_segment_manager(), it may cause use-after-free
issue when umount races with procfs accessing, fix it by relocating
f2fs_unregister_sysfs().
[Chao Yu: change commit title/message a bit]
Signed-off-by: Li Guifu <[email protected]>
Reviewed-by: Chao Yu <[email protected]>
---
v2:
- fix typo in commit message.
- improve comment in f2fs_put_super() a bit.
fs/f2fs/super.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 80cb7cd358f8..5e0a3eeb8ca4 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1175,6 +1175,9 @@ static void f2fs_put_super(struct super_block *sb)
int i;
bool dropped;
+ /* unregister procfs/sysfs entries in advance to avoid race case */
+ f2fs_unregister_sysfs(sbi);
+
f2fs_quota_off_umount(sb);
/* prevent remaining shrinker jobs */
@@ -1240,8 +1243,6 @@ static void f2fs_put_super(struct super_block *sb)
kvfree(sbi->ckpt);
- f2fs_unregister_sysfs(sbi);
-
sb->s_fs_info = NULL;
if (sbi->s_chksum_driver)
crypto_free_shash(sbi->s_chksum_driver);
--
2.26.2