diff mbox series

[4.19,037/125] f2fs: fix use-after-free issue

Message ID 20200901150936.376893944@linuxfoundation.org
State Superseded
Headers show
Series None | expand

Commit Message

Greg KH Sept. 1, 2020, 3:09 p.m. UTC 
From: Li Guifu <bluce.liguifu@huawei.com>

[ Upstream commit 99c787cfd2bd04926f1f553b30bd7dcea2caaba1 ]

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 <bluce.liguifu@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/f2fs/super.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)
diff mbox series

Patch

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 9782250c98156..161ce0eb8891a 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -1004,6 +1004,9 @@  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 */
@@ -1067,8 +1070,6 @@  static void f2fs_put_super(struct super_block *sb)
 
 	kfree(sbi->ckpt);
 
-	f2fs_unregister_sysfs(sbi);
-
 	sb->s_fs_info = NULL;
 	if (sbi->s_chksum_driver)
 		crypto_free_shash(sbi->s_chksum_driver);