Hello, syzbot found the following crash on: HEAD commit: 770fbb32 Add linux-next specific files for 20200228 git tree: linux-next console output: https://syzkaller.appspot.com/x/log.txt?x=16974813e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=576314276bce4ad5 dashboard link: https://syzkaller.appspot.com/bug?extid=c8f52ab16178cebd5f5c compiler: gcc (GCC) 9.0.0 20181231 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=14fa5e75e00000 Bisection is inconclusive: the bug happens on the oldest tested release. bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14eeae75e00000 final crash: https://syzkaller.appspot.com/x/report.txt?x=16eeae75e00000 console output: https://syzkaller.appspot.com/x/log.txt?x=12eeae75e00000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+c8f52ab16178cebd5f5c@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: null-ptr-deref in kvm_vfio_set_group arch/x86/kvm/../../../virt/kvm/vfio.c:235 [inline] BUG: KASAN: null-ptr-deref in kvm_vfio_set_attr+0x7da/0xa30 arch/x86/kvm/../../../virt/kvm/vfio.c:337 Read of size 8 at addr 0000000000000000 by task syz-executor.2/9641 CPU: 0 PID: 9641 Comm: syz-executor.2 Not tainted 5.6.0-rc3-next-20200228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 __kasan_report.cold+0x5/0x32 mm/kasan/report.c:510 kasan_report+0xe/0x20 mm/kasan/common.c:618 kvm_vfio_set_group arch/x86/kvm/../../../virt/kvm/vfio.c:235 [inline] kvm_vfio_set_attr+0x7da/0xa30 arch/x86/kvm/../../../virt/kvm/vfio.c:337 </IRQ> ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 9641 Comm: syz-executor.2 Tainted: G B 5.6.0-rc3-next-20200228-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: <IRQ> __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x188/0x20d lib/dump_stack.c:118 panic+0x2e3/0x75c kernel/panic.c:221 end_report+0x43/0x49 mm/kasan/report.c:96 __kasan_report.cold+0xd/0x32 mm/kasan/report.c:513 kasan_report+0xe/0x20 mm/kasan/common.c:618 kvm_vfio_set_group arch/x86/kvm/../../../virt/kvm/vfio.c:235 [inline] kvm_vfio_set_attr+0x7da/0xa30 arch/x86/kvm/../../../virt/kvm/vfio.c:337 </IRQ> Shutting down cpus with NMI Kernel Offset: disabled Rebooting in 86400 seconds.. --- 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
