On Sat, Mar 14, 2020 at 7:37 AM syzbot <syzbot+8b0e78e390d1715b0f4e@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: 30bb5572 Merge tag 'ktest-v5.6' of git://git.kernel.org/pu.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=15d300b1e00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=a5295e161cd85b82 > dashboard link: https://syzkaller.appspot.com/bug?extid=8b0e78e390d1715b0f4e > compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=11a57709e00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=13de9e91e00000 Looking at the reproducer, it's all KVM, +KVM maintainers. > The bug was bisected to: > > commit 271213ef4d0d3a3b80d4cf95c5f2bebb5643e666 > Author: Takashi Iwai <tiwai@xxxxxxx> > Date: Tue Dec 10 06:34:50 2019 +0000 > > ALSA: pcxhr: Support PCM sync_stop > > bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=1566b08de00000 > final crash: https://syzkaller.appspot.com/x/report.txt?x=1766b08de00000 > console output: https://syzkaller.appspot.com/x/log.txt?x=1366b08de00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+8b0e78e390d1715b0f4e@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: 271213ef4d0d ("ALSA: pcxhr: Support PCM sync_stop") > > BUG: kernel NULL pointer dereference, address: 0000000000000086 > #PF: supervisor instruction fetch in kernel mode > #PF: error_code(0x0010) - not-present page > PGD a27fa067 P4D a27fa067 PUD a2185067 PMD 0 > Oops: 0010 [#1] PREEMPT SMP KASAN > CPU: 1 PID: 9168 Comm: syz-executor418 Not tainted 5.6.0-rc5-syzkaller #0 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 > RIP: 0010:0x86 > Code: Bad RIP value. > RSP: 0018:ffffc90002c9f998 EFLAGS: 00010086 > RAX: ffffc90002c9f9c8 RBX: fffffe0000000000 RCX: ffff8880a31b6280 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 > RBP: 0000000000000ec0 R08: ffffffff839888d3 R09: ffffffff811c7d9a > R10: ffff8880a31b6280 R11: 0000000000000002 R12: dffffc0000000000 > R13: fffffe0000000ec8 R14: ffffffff880016f0 R15: fffffe0000000ecb > FS: 0000000000981880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000000005c CR3: 00000000986d2000 CR4: 00000000001426e0 > Call Trace: > Modules linked in: > CR2: 0000000000000086 > ---[ end trace 7c78bc94cfc0a37d ]--- > RIP: 0010:0x86 > Code: Bad RIP value. > RSP: 0018:ffffc90002c9f998 EFLAGS: 00010086 > RAX: ffffc90002c9f9c8 RBX: fffffe0000000000 RCX: ffff8880a31b6280 > RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 > RBP: 0000000000000ec0 R08: ffffffff839888d3 R09: ffffffff811c7d9a > R10: ffff8880a31b6280 R11: 0000000000000002 R12: dffffc0000000000 > R13: fffffe0000000ec8 R14: ffffffff880016f0 R15: fffffe0000000ecb > FS: 0000000000981880(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 000000000000005c CR3: 00000000986d2000 CR4: 00000000001426e0 > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > For information about bisection process see: https://goo.gl/tpsmEJ#bisection > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches