Re: BUG: unable to handle kernel paging request in ipcget

[Dmitry Vyukov]

On Tue, Jan 2, 2018 at 7:16 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote:
> On Sat, Dec 23, 2017 at 2:07 AM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
>> On Sat, Dec 23, 2017 at 10:59 AM, Manfred Spraul
>> <manfred@xxxxxxxxxxxxxxxx> wrote:
>>> Hi,
>>>
>>> On 12/23/2017 08:33 AM, syzbot wrote:
>>>>
>>>> Hello,
>>>>
>>>> syzkaller hit the following crash on
>>>> 6084b576dca2e898f5c101baef151f7bfdbb606d
>>>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master
>>>> compiler: gcc (GCC) 7.1.1 20170620
>>>> .config is attached
>>>> Raw console output is attached.
>>>>
>>>> Unfortunately, I don't have any reproducer for this bug yet.
>>>>
>>> Is one of the recent issues reproducible?
>>
>> Which one do you mean?
>> syzbot always provides up-to-date status of reproducers for all reported bugs.
>>
>>> Either something is wrong with the faster ipc_get, or the improved ipc_get
>>> makes issues in other areas visible.
>
> Was this report related to the recent set of kmalloc-1024 false positives?


That's possible. It happened only twice and is unexplainable (right?). Let's do:

#syz fix: crypto: pcrypt - fix freeing pcrypt instances

and see if this happens again after the commit lands.