Re: KASAN: use-after-scope Read in __hrtimer_run_queues
From: Dmitry Vyukov
Date: Thu Jul 05 2018 - 12:20:39 EST
On Wed, Jul 4, 2018 at 5:27 PM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote:
> On Wed, Jul 4, 2018 at 5:20 PM, Thomas Gleixner <tglx@xxxxxxxxxxxxx> wrote:
>> On Wed, 4 Jul 2018, syzbot wrote:
>>> syzbot found the following crash on:
>>> HEAD commit: 2bdea157b999 Merge branch 'sctp-fully-support-for-dscp-and..
>>> git tree: bpf-next
>>> console output: https://syzkaller.appspot.com/x/log.txt?x=14339f42400000
>>> kernel config: https://syzkaller.appspot.com/x/.config?x=f62553dc846b0692
>>> dashboard link: https://syzkaller.appspot.com/bug?extid=7f73a81393d3b3777fb0
>>> compiler: gcc (GCC) 8.0.1 20180413 (experimental)
>>> Unfortunately, I don't have any reproducer for this crash yet.
>>> IMPORTANT: if you fix the bug, please add the following tag to the commit:
>>> Reported-by: syzbot+7f73a81393d3b3777fb0@xxxxxxxxxxxxxxxxxxxxxxxxx
>>> BUG: KASAN: use-after-scope in lookup_object lib/debugobjects.c:157 [inline]
>>> BUG: KASAN: use-after-scope in debug_object_deactivate+0x425/0x450
>>> Read of size 8 at addr ffff88019d1a5ec0 by task syz-executor3/13445
>> I don't see how lib/debugobjects.c:157 would be a valid use after scope
>> issue. The one in line 540 makes no sense either.
> Hi Thomas,
> They all don't make sense:
> One of them says "stack overflow", so there seems to be a serious
> system corruption that now leads to assorted nonsensical crashes. And
> this seems to be a very recent change.
#syz dup: KASAN: stack-out-of-bounds Read in timerqueue_add