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

[Shuangpeng Bai]

I will follow the suggestions. Thank you! 

> On May 16, 2024, at 10:44, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> 
> 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