Try disabling the module parameter, "unrestricted_guest." Make sure that the module parameter, "emulate_invalid_guest_state" is enabled. This combination allows userspace to feed invalid guest state into the in-kernel emulator. On Thu, Dec 7, 2017 at 2:40 AM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote: > 2017-12-07 15:52 GMT+08:00 Wanpeng Li <kernellwp@xxxxxxxxx>: >> 2017-12-07 15:49 GMT+08:00 蓝天宇 <lantianyu1986@xxxxxxxxx>: >>> Hi Dmitry: >>> I tried to reproduce the issue via syz-execprog with attached >>> reproducer on latest linux-next but it causes VM-entry failure due to >>> invalid guest state... >> >> Because rflags is 0 in his program. You can set ept=0 and retry. > > In addition, you can apply this commit > https://lkml.org/lkml/2017/12/7/144 before testing. > >> >> Regards, >> Wanpeng Li >> >>> >>> 2017-12-07 14:25 GMT+08:00 Dmitry Vyukov <dvyukov@xxxxxxxxxx>: >>>> On Thu, Dec 7, 2017 at 1:44 AM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote: >>>>> 2017-12-06 4:07 GMT+08:00 syzbot >>>>> <bot+75375385991b4f8c599704a10849863c586ea284@xxxxxxxxxxxxxxxxxxxxxxxxx>: >>>>>> Hello, >>>>>> >>>>>> syzkaller hit the following crash on >>>>>> fb20eb9d798d2f4c1a75b7fe981d72dfa8d7270d >>>>>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master >>>>>> compiler: gcc (GCC) 7.1.1 20170620 >>>>>> .config is attached >>>>>> Raw console output is attached. >>>>>> >>>>>> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >>>>>> for information about syzkaller reproducers >>>>>> >>>>> >>>>> Is there a c program to reproduce? >>>> >>>> No, syzbot does not hide reproducers. See the referenced doc for >>>> details: https://github.com/google/syzkaller/blob/master/docs/syzbot.md#syzkaller-reproducers >>>> >>>> >>>>> Regards, >>>>> Wanpeng Li >>>>> >>>>>> >>>>>> kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu >>>>>> WARNING: CPU: 1 PID: 3526 at arch/x86/kvm/emulate.c:5654 >>>>>> x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654 >>>>>> Kernel panic - not syncing: panic_on_warn set ... >>>>>> >>>>>> CPU: 1 PID: 3526 Comm: syz-executor4 Not tainted 4.15.0-rc1-next-20171201+ >>>>>> #57 >>>>>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>>>>> Google 01/01/2011 >>>>>> Call Trace: >>>>>> __dump_stack lib/dump_stack.c:17 [inline] >>>>>> dump_stack+0x194/0x257 lib/dump_stack.c:53 >>>>>> panic+0x1e4/0x41c kernel/panic.c:183 >>>>>> __warn+0x1dc/0x200 kernel/panic.c:547 >>>>>> report_bug+0x211/0x2d0 lib/bug.c:184 >>>>>> fixup_bug.part.11+0x37/0x80 arch/x86/kernel/traps.c:177 >>>>>> fixup_bug arch/x86/kernel/traps.c:246 [inline] >>>>>> do_error_trap+0x2d7/0x3e0 arch/x86/kernel/traps.c:295 >>>>>> do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:314 >>>>>> invalid_op+0x22/0x40 arch/x86/entry/entry_64.S:1066 >>>>>> RIP: 0010:x86_emulate_insn+0xd01/0x3cf0 arch/x86/kvm/emulate.c:5654 >>>>>> RSP: 0018:ffff8801d0fff3e8 EFLAGS: 00010293 >>>>>> RAX: ffff8801d17b60c0 RBX: 1ffff1003a1ffe86 RCX: ffffffff81154351 >>>>>> RDX: 0000000000000000 RSI: ffffffffffffffff RDI: ffff8801d0b5b5c8 >>>>>> RBP: ffff8801d0fff4f8 R08: ffff8801d0b58d80 R09: ffffffff85224da0 >>>>>> R10: 0000000000000001 R11: ffffed003a16b6d4 R12: 00000000000000ff >>>>>> R13: ffff8801d0b5b5a0 R14: 0000000000000002 R15: ffff8801d0b5b6c3 >>>>>> x86_emulate_instruction+0x411/0x1ad0 arch/x86/kvm/x86.c:5771 >>>>>> emulate_instruction arch/x86/include/asm/kvm_host.h:1164 [inline] >>>>>> complete_emulated_io arch/x86/kvm/x86.c:7190 [inline] >>>>>> complete_emulated_pio+0xdd/0x1b0 arch/x86/kvm/x86.c:7201 >>>>>> kvm_arch_vcpu_ioctl_run+0x2db2/0x5c60 arch/x86/kvm/x86.c:7305 >>>>>> kvm_vcpu_ioctl+0x64c/0x1010 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2574 >>>>>> vfs_ioctl fs/ioctl.c:46 [inline] >>>>>> do_vfs_ioctl+0x1b1/0x1530 fs/ioctl.c:686 >>>>>> SYSC_ioctl fs/ioctl.c:701 [inline] >>>>>> SyS_ioctl+0x8f/0xc0 fs/ioctl.c:692 >>>>>> entry_SYSCALL_64_fastpath+0x1f/0x96 >>>>>> RIP: 0033:0x4529d9 >>>>>> RSP: 002b:00007f6b6b2d5c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000010 >>>>>> RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 00000000004529d9 >>>>>> RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000004 >>>>>> RBP: 000000000000039b R08: 0000000000000000 R09: 0000000000000000 >>>>>> R10: 0000000000000000 R11: 0000000000000212 R12: 00000000006f2728 >>>>>> R13: 00000000ffffffff R14: 00007f6b6b2d66d4 R15: 0000000000000000 >>>>>> Dumping ftrace buffer: >>>>>> (ftrace buffer empty) >>>>>> Kernel Offset: disabled >>>>>> Rebooting in 86400 seconds.. >>>>>> >>>>>> >>>>>> --- >>>>>> This bug is generated by a dumb bot. It may contain errors. >>>>>> See https://goo.gl/tpsmEJ for details. >>>>>> Direct all questions to syzkaller@xxxxxxxxxxxxxxxx. >>>>>> Please credit me with: Reported-by: syzbot <syzkaller@xxxxxxxxxxxxxxxx> >>>>>> >>>>>> syzbot will keep track of this bug report. >>>>>> Once a fix for this bug is committed, please reply to this email with: >>>>>> #syz fix: exact-commit-title >>>>>> If you want to test a patch for this bug, please reply with: >>>>>> #syz test: git://repo/address.git branch >>>>>> and provide the patch inline or as an attachment. >>>>>> To mark this as a duplicate of another syzbot report, please reply with: >>>>>> #syz dup: exact-subject-of-another-report >>>>>> If it's a one-off invalid bug report, please reply with: >>>>>> #syz invalid >>>>>> Note: if the crash happens again, it will cause creation of a new bug >>>>>> report. >>>>>> Note: all commands must start from beginning of the line in the email body. >>>>> >>>>> -- >>>>> You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. >>>>> To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@xxxxxxxxxxxxxxxx. >>>>> To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CANRm%2BCw6u-Tvq6M%2B8hFm9UmxyTWsqvrm5L9bzfoTAvEsaeC1-w%40mail.gmail.com. >>>>> For more options, visit https://groups.google.com/d/optout. >>> >>> >>> >>> -- >>> Best regards >>> Tianyu Lan
