From: Tetsuo Handa Date: Wed, 13 Aug 2025 07:17:43 +0000 (+0900) Subject: squashfs: verify inode mode when loading from disk X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=bc107a619f029415e0a87e6df16f995553da4568;p=users%2Fhch%2Fmisc.git squashfs: verify inode mode when loading from disk The inode mode loaded from corrupted disk might by error contain the file type bits. Since the file type bits are set by squashfs_read_inode() using bitwise OR, the file type bits must not be set by squashfs_new_inode() from squashfs_read_inode(); otherwise, an invalid file type bits later confuses may_open(). Link: https://lkml.kernel.org/r/f63d8d11-2254-4fc3-9292-9a43a93b374e@I-love.SAKURA.ne.jp Reported-by: syzbot Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d Signed-off-by: Tetsuo Handa Reviewed-by: Phillip Lougher Signed-off-by: Andrew Morton --- diff --git a/fs/squashfs/inode.c b/fs/squashfs/inode.c index d5918eba27e3..dee8fa016930 100644 --- a/fs/squashfs/inode.c +++ b/fs/squashfs/inode.c @@ -68,6 +68,10 @@ static int squashfs_new_inode(struct super_block *sb, struct inode *inode, inode->i_mode = le16_to_cpu(sqsh_ino->mode); inode->i_size = 0; + /* File type must not be set at this moment, for it will later be set by the caller. */ + if (inode->i_mode & S_IFMT) + err = -EIO; + return err; }