From: Jan Kara jack@suse.cz
[ Upstream commit 85a37983ec69cc9fcd188bc37c4de15ee326355a ]
When UDF filesystem is corrupted, hidden system inodes can be linked into directory hierarchy which is an avenue for further serious corruption of the filesystem and kernel confusion as noticed by syzbot fuzzed images. Refuse to access system inodes linked into directory hierarchy and vice versa.
CC: stable@vger.kernel.org Reported-by: syzbot+38695a20b8addcbc1084@syzkaller.appspotmail.com Signed-off-by: Jan Kara jack@suse.cz Signed-off-by: Sasha Levin sashal@kernel.org --- fs/udf/inode.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 7436337914b19..77421e65623a1 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1871,8 +1871,13 @@ struct inode *__udf_iget(struct super_block *sb, struct kernel_lb_addr *ino, if (!inode) return ERR_PTR(-ENOMEM);
- if (!(inode->i_state & I_NEW)) + if (!(inode->i_state & I_NEW)) { + if (UDF_I(inode)->i_hidden != hidden_inode) { + iput(inode); + return ERR_PTR(-EFSCORRUPTED); + } return inode; + }
memcpy(&UDF_I(inode)->i_location, ino, sizeof(struct kernel_lb_addr)); err = udf_read_inode(inode, hidden_inode);