From 85a37983ec69cc9fcd188bc37c4de15ee326355a Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 3 Jan 2023 10:03:35 +0100 Subject: [PATCH] udf: Detect system inodes linked into directory hierarchy 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 --- 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 9ee269d..96873fa 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1813,8 +1813,13 @@ 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); -- 2.7.4