Re: KASAN: use-after-free in ext4_find_extent in v6.9

[Dmitry Vyukov]

On Thu, 16 May 2024 at 15:58, Theodore Ts'o <tytso@xxxxxxx> wrote:
>
> On Wed, May 15, 2024 at 08:33:33PM -0400, Shuangpeng Bai wrote:
> >
> > You are right. I disabled CONFIG_BLK_DEV_WRITE_MOUNTED and found
> > this bug can not be triggered anymore.
> >
> > I am wondering if there is any suggested way for me to check whether
> > a bug is reproduced under a reasonable environment (such as
> > compiling config) or not? If so, that would be very helpful.
>
> As I mentioned, the upstream syzkaller always forces the
> CONFIG_BLK_DEV_WRITE_MOUNTED to be disabled.  That's the best way to
> check whether the bug is reproducible under a reasonable environment,
> and to do it in an automated way.

FWIW we provide configs used by syzbot here (upstream-*):
https://github.com/google/syzkaller/tree/master/dashboard/config/linux

+ a bunch of configs fragments with explanations why things are
enabled/disabled:
https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/maintained.yml
https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/base.yml
https://github.com/google/syzkaller/blob/master/dashboard/config/linux/bits/debug.yml