1
0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-01-12 01:20:14 +00:00
Tetsuo Handa 34ab4c7558
bfs: Reconstruct file type when loading from disk
syzbot is reporting that S_IFMT bits of inode->i_mode can become bogus when
the S_IFMT bits of the 32bits "mode" field loaded from disk are corrupted
or when the 32bits "attributes" field loaded from disk are corrupted.

A documentation says that BFS uses only lower 9 bits of the "mode" field.
But I can't find an explicit explanation that the unused upper 23 bits
(especially, the S_IFMT bits) are initialized with 0.

Therefore, ignore the S_IFMT bits of the "mode" field loaded from disk.
Also, verify that the value of the "attributes" field loaded from disk is
either BFS_VREG or BFS_VDIR (because BFS supports only regular files and
the root directory).

Reported-by: syzbot+895c23f6917da440ed0d@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://patch.msgid.link/fabce673-d5b9-4038-8287-0fd65d80203b@I-love.SAKURA.ne.jp
Reviewed-by: Tigran Aivazian <aivazian.tigran@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-10-29 14:39:34 +01:00
..
2025-07-28 13:43:25 -07:00
2023-08-02 09:13:09 -06:00