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 -- Jens Axboe