Re: WARNING in kmem_cache_free

Dmitry Vyukov
2018-04-08T15:41:40Z

On Sun, Apr 8, 2018 at 5:31 PM, Stephan Müller <smueller@chronox.de> wrote:
> Am Sonntag, 8. April 2018, 13:18:06 CEST schrieb Dmitry Vyukov:
>
> Hi Dmitry,
>
>>
>> Running syz-repro utility on this log, I think I've found the guilty guy:
>> https://gist.githubusercontent.com/dvyukov/1dd75d55efd238e7207af1cc38478b3a/
>> raw/403859b56b161a6fbb158e8953fac5bb6e73b1a1/gistfile1.txt
>>
>
> I am unable to reproduce it with the code. I am using the current
> cryptodev-2.6 tree with kazan enabled. Could you please give me your kernel
> config or a pointer of the used tree?

Hi,

Here is config and kernel commit:
https://groups.google.com/d/msg/syzkaller-bugs/PINYyzoaG1s/ntZPOZdcCAAJ
You can also find compiler and image here if necessary:
https://github.com/google/syzkaller/blob/master/docs/syzbot.md

And note that the program needs to be compiled with -m32. The bugs is
probably not-compat specific, but the program injects fault into a
particular malloc invocation and maybe malloc numbering is affected by
compat path.

>> It crashes as:
>> BUG: KASAN: use-after-free in drbg_kcapi_seed+0x1178/0x12e0
>> and:
>> BUG: unable to handle kernel paging request at ffffebe000000020
>> and with other indications of badly corrupted heap.
>>
>> This points to crypto/drbg.c, so +crypto maintainers.
>
>
> Ciao
> Stephan
>
>
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