From 1f328751b65c49c13a312d67a3bf27766b85baf7 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 commit 85a37983ec69cc9fcd188bc37c4de15ee326355a upstream. 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 Signed-off-by: Greg Kroah-Hartman --- 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 52ffbe2b56d7..33eb3a67c31d 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -1892,8 +1892,13 @@ 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); -- 2.50.1