Re: [PATCH v2] proc: s_fs_info may be NULL when proc_kill_sb is called

From: Eric W. Biederman
Date: Wed Jun 10 2020 - 16:21:36 EST


Alexey Gladkov <gladkov.alexey@xxxxxxxxx> writes:

> syzbot found that proc_fill_super() fails before filling up sb->s_fs_info,
> deactivate_locked_super() will be called and sb->s_fs_info will be NULL.
> The proc_kill_sb() does not expect fs_info to be NULL which is wrong.
>
> Link: https://lore.kernel.org/lkml/0000000000002d7ca605a7b8b1c5@xxxxxxxxxx
> Reported-by: syzbot+4abac52934a48af5ff19@xxxxxxxxxxxxxxxxxxxxxxxxx
> Fixes: fa10fed30f25 ("proc: allow to mount many instances of proc in one pid namespace")
> Signed-off-by: Alexey Gladkov <gladkov.alexey@xxxxxxxxx>

applied

Eric