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

From: Dmitry Vyukov
Date: Thu Dec 21 2017 - 02:44:37 EST


On Thu, Dec 21, 2017 at 12:09 AM, Eric Biggers <ebiggers3@xxxxxxxxx> wrote:
> On Mon, Dec 18, 2017 at 11:36:01AM -0800, 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
>
> FYI, in linux-next KASAN and other memory debugging options are now behind
> CONFIG_DEBUG_MEMORY. So, I think KASAN isn't getting turned on anymore, despite
> the CONFIG_KASAN=y. (Patch was "lib/: make "Memory Debugging" a menuconfig to
> ease disabling it all".)

Ouch! That would be pretty bad.

But I've tried both linux-next HEAD at:

commit 0e08c463db387a2adcb0243b15ab868a73f87807 (HEAD, tag:
next-20171221, linux-next/master)
Author: Stephen Rothwell <sfr@xxxxxxxxxxxxxxxx>
Date: Thu Dec 21 15:37:39 2017 +1100
Add linux-next specific files for 20171221

and mmots HEAD at:

commit 75aa5540627fdb3d8f86229776ea87f995275351 (HEAD, tag:
v4.15-rc4-mmots-2017-12-20-19-10, mmots/master)
Author: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Date: Thu Dec 21 04:02:17 2017 +0000
pci: test for unexpectedly disabled bridges

and after running make olddefconfig I still see CONFIG_KASAN=y in
.config, nor I can find CONFIG_DEBUG_MEMORY in menuconfig.

What am I missing? What commit has added the config?