Hello, syzbot found the following crash on: HEAD commit: 7ae77150 Merge tag 'powerpc-5.8-1' of git://git.kernel.org.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=17d9bfa9100000 kernel config: https://syzkaller.appspot.com/x/.config?x=be4578b3f1083656 dashboard link: https://syzkaller.appspot.com/bug?extid=76004d8cdf5443dcd8e7 compiler: clang version 10.0.0 (https://github.com/llvm/llvm-project/ c2443155a0fb245c8f17f2c1c72b6ea391e86e81) 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+76004d8cdf5443dcd8e7@xxxxxxxxxxxxxxxxxxxxxxxxx ================================================================== BUG: KASAN: null-ptr-deref in kvm_vcpu_halt+0xea/0x110 arch/x86/kvm/x86.c:7546 Write of size 4 at addr 0000000000000000 by task syz-executor.0/11111 CPU: 1 PID: 11111 Comm: syz-executor.0 Not tainted 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 __kasan_report mm/kasan/report.c:517 [inline] kasan_report+0x151/0x1d0 mm/kasan/report.c:530 kvm_vcpu_halt+0xea/0x110 arch/x86/kvm/x86.c:7546 </IRQ> ================================================================== Kernel panic - not syncing: panic_on_warn set ... CPU: 1 PID: 11111 Comm: syz-executor.0 Tainted: G B 5.7.0-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+0x1e9/0x30e lib/dump_stack.c:118 panic+0x264/0x7a0 kernel/panic.c:221 end_report mm/kasan/report.c:104 [inline] __kasan_report mm/kasan/report.c:520 [inline] kasan_report+0x1c9/0x1d0 mm/kasan/report.c:530 kvm_vcpu_halt+0xea/0x110 arch/x86/kvm/x86.c:7546 </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.