On Wed, Sep 08 2021 at 11:20, Jens Axboe wrote: > On 9/8/21 11:02 AM, Jens Axboe wrote: >> On 9/8/21 10:45 AM, Thomas Gleixner wrote: >>> On Mon, Sep 06 2021 at 03:28, syzbot wrote: >>>> syzbot found the following issue on: >>>> >>>> HEAD commit: 835d31d319d9 Merge tag 'media/v5.15-1' of git://git.kernel.. >>>> git tree: upstream >>>> console output: https://syzkaller.appspot.com/x/log.txt?x=14489886300000 >>>> kernel config: https://syzkaller.appspot.com/x/.config?x=d793523866f2daea >>>> dashboard link: https://syzkaller.appspot.com/bug?extid=b935db3fe409625cca1b >>>> compiler: Debian clang version 11.0.1-2, GNU ld (GNU Binutils for Debian) 2.35.1 >>>> >>>> Unfortunately, I don't have any reproducer for this issue yet. >>>> >>>> IMPORTANT: if you fix the issue, please add the following tag to the commit: >>>> Reported-by: syzbot+b935db3fe409625cca1b@xxxxxxxxxxxxxxxxxxxxxxxxx >>>> >>>> general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN >>>> KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] >>>> CPU: 0 PID: 12936 Comm: iou-sqp-12929 Not tainted 5.14.0-syzkaller #0 >>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 >>>> RIP: 0010:lock_hrtimer_base kernel/time/hrtimer.c:173 [inline] >>> >>> That's almost certainly deferencing hrtimer->base and as that is NULL >>> this looks like a not initialized hrtimer. >> >> Does certainly look like that, I'll take a look. And agree the next one >> looks like the same thing. > > I think both are fallout from a regression that we had in linked > requests, where we'd queue requests that weren't fully prepared. Current > Linus -git should not have this problem: > > These were the two related fixes: > > io_uring: fix queueing half-created requests > io_uring: don't submit half-prepared drain request Makes sense and the backtraces in the changelogs point at the same class of problem. Thanks, tglx
