This is a note to let you know that I've just added the patch titled
udf: Verify inode link counts before performing rename
to the 6.12-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
udf-verify-inode-link-counts-before-performing-renam.patch
and it can be found in the queue-6.12 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ed2cf146ebf022106b5222452e71e9470e2371e4
Author: Jan Kara <jack@xxxxxxx>
Date: Tue Nov 26 12:55:12 2024 +0100
udf: Verify inode link counts before performing rename
[ Upstream commit 6756af923e06aa33ad8894aaecbf9060953ba00f ]
During rename, we are updating link counts of various inodes either when
rename deletes target or when moving directory across directories.
Verify involved link counts are sane so that we don't trip warnings in
VFS.
Reported-by: syzbot+3ff7365dc04a6bcafa66@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Jan Kara <jack@xxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/fs/udf/namei.c b/fs/udf/namei.c
index 2be775d30ac1..2cb49b6b0716 100644
--- a/fs/udf/namei.c
+++ b/fs/udf/namei.c
@@ -791,8 +791,18 @@ static int udf_rename(struct mnt_idmap *idmap, struct inode *old_dir,
retval = -ENOTEMPTY;
if (!empty_dir(new_inode))
goto out_oiter;
+ retval = -EFSCORRUPTED;
+ if (new_inode->i_nlink != 2)
+ goto out_oiter;
}
+ retval = -EFSCORRUPTED;
+ if (old_dir->i_nlink < 3)
+ goto out_oiter;
is_dir = true;
+ } else if (new_inode) {
+ retval = -EFSCORRUPTED;
+ if (new_inode->i_nlink < 1)
+ goto out_oiter;
}
if (is_dir && old_dir != new_dir) {
retval = udf_fiiter_find_entry(old_inode, &dotdot_name,
