[PATCH AUTOSEL 6.6 05/23] udf: Skip parent dir link count update if corrupted

From: Sasha Levin
Date: Wed Dec 11 2024 - 14:00:05 EST


From: Jan Kara <jack@xxxxxxx>

[ Upstream commit c5566903af56dd1abb092f18dcb0c770d6cd8dcb ]

If the parent directory link count is too low (likely directory inode
corruption), just skip updating its link count as if it goes to 0 too
early it can cause unexpected issues.

Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
fs/udf/namei.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 605f182da42cb..b3f57ad2b869f 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -521,7 +521,11 @@ static int udf_rmdir(struct inode *dir, struct dentry *dentry)
inode->i_nlink);
clear_nlink(inode);
inode->i_size = 0;
- inode_dec_link_count(dir);
+ if (dir->i_nlink >= 3)
+ inode_dec_link_count(dir);
+ else
+ udf_warn(inode->i_sb, "parent dir link count too low (%u)\n",
+ dir->i_nlink);
udf_add_fid_counter(dir->i_sb, true, -1);
dir->i_mtime = inode_set_ctime_to_ts(dir,
inode_set_ctime_current(inode));
--
2.43.0