On Tue, Dec 26, 2017 at 9:52 AM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > On Wed, Dec 20, 2017 at 8:54 AM, Wanpeng Li <kernellwp@xxxxxxxxx> wrote: >> 2017-12-20 15:49 GMT+08:00 syzbot >> <bot+ab09454bf4b7a7f8ce7e5e8d97e644d3314a0799@xxxxxxxxxxxxxxxxxxxxxxxxx>: >>> Hello, >>> >>> syzkaller hit the following crash on >>> f6f3732162b5ae3c771b9285a5a32d72b8586920 >>> git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/master >>> compiler: gcc (GCC) 7.1.1 20170620 >>> .config is attached >>> Raw console output is attached. >>> C reproducer is attached >>> syzkaller reproducer is attached. See https://goo.gl/kgGztJ >>> for information about syzkaller reproducers >>> >>> >> >> I will have a look again, you continue to run it in kvm guest, right? > > > Our test machines are GCE VMs, so yes, the kernel that catches GPF is > run as kvm guest. up one of top crashers with 50K crashes >>> kvm: KVM_SET_TSS_ADDR need to be called before entering vcpu >>> kasan: CONFIG_KASAN_INLINE enabled >>> kasan: GPF could be caused by NULL-ptr deref or user memory access >>> general protection fault: 0000 [#1] SMP KASAN >>> Dumping ftrace buffer: >>> (ftrace buffer empty) >>> Modules linked in: >>> CPU: 1 PID: 3142 Comm: syzkaller429302 Not tainted 4.15.0-rc3+ #224 >>> Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS >>> Google 01/01/2011 >>> RIP: 0010:native_write_cr4+0x4/0x10 arch/x86/include/asm/special_insns.h:76 >>> RSP: 0018:ffff8801ca6f75a0 EFLAGS: 00010093 >>> RAX: ffff8801ca1c8700 RBX: 00000000001606e0 RCX: ffffffff811a2a92 >>> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000001606e0 >>> RBP: ffff8801ca6f75a0 R08: 1ffff100394dee0f R09: 0000000000000004 >>> R10: ffff8801ca6f7510 R11: 0000000000000004 R12: 0000000000000093 >>> R13: ffff8801ca1c8700 R14: ffff8801db514850 R15: ffff8801db514850 >>> FS: 0000000001031880(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 0000000000000000 CR3: 0000000005e22006 CR4: 00000000001626e0 >>> Call Trace: >>> __write_cr4 arch/x86/include/asm/paravirt.h:76 [inline] >>> __cr4_set arch/x86/include/asm/tlbflush.h:180 [inline] >>> cr4_clear_bits arch/x86/include/asm/tlbflush.h:203 [inline] >>> kvm_cpu_vmxoff arch/x86/kvm/vmx.c:3582 [inline] >>> hardware_disable+0x34a/0x4b0 arch/x86/kvm/vmx.c:3588 >>> kvm_arch_hardware_disable+0x35/0xd0 arch/x86/kvm/x86.c:7982 >>> hardware_disable_nolock+0x30/0x40 >>> arch/x86/kvm/../../../virt/kvm/kvm_main.c:3310 >>> on_each_cpu+0xca/0x1b0 kernel/smp.c:604 >>> hardware_disable_all_nolock+0x3e/0x50 >>> arch/x86/kvm/../../../virt/kvm/kvm_main.c:3328 >>> hardware_disable_all arch/x86/kvm/../../../virt/kvm/kvm_main.c:3334 >>> [inline] >>> kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:742 [inline] >>> kvm_put_kvm+0x956/0xdf0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:755 >>> kvm_vm_release+0x42/0x50 arch/x86/kvm/../../../virt/kvm/kvm_main.c:766 >>> __fput+0x327/0x7e0 fs/file_table.c:210 >>> ____fput+0x15/0x20 fs/file_table.c:244 >>> task_work_run+0x199/0x270 kernel/task_work.c:113 >>> exit_task_work include/linux/task_work.h:22 [inline] >>> do_exit+0x9bb/0x1ad0 kernel/exit.c:865 >>> do_group_exit+0x149/0x400 kernel/exit.c:968 >>> SYSC_exit_group kernel/exit.c:979 [inline] >>> SyS_exit_group+0x1d/0x20 kernel/exit.c:977 >>> entry_SYSCALL_64_fastpath+0x1f/0x96 >>> RIP: 0033:0x441c78 >>> RSP: 002b:00007ffe68e20f68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 >>> RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000441c78 >>> RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 >>> RBP: 00000000006cd018 R08: 00000000000000e7 R09: ffffffffffffffd0 >>> R10: 0000000000000012 R11: 0000000000000246 R12: 0000000000404080 >>> R13: 0000000000404110 R14: 0000000000000000 R15: 0000000000000000 >>> Code: 0f 1f 80 00 00 00 00 55 48 89 e5 0f 20 d8 5d c3 0f 1f 80 00 00 00 00 >>> 55 48 89 e5 0f 22 df 5d c3 0f 1f 80 00 00 00 00 55 48 89 e5 <0f> 22 e7 5d c3 >>> 0f 1f 80 00 00 00 00 55 48 89 e5 44 0f 20 c0 5d >>> RIP: native_write_cr4+0x4/0x10 arch/x86/include/asm/special_insns.h:76 RSP: >>> ffff8801ca6f75a0 >>> ---[ end trace ca14f0c15b26c251 ]--- >>> >>> >>> --- >>> 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 merged into any tree, 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%2BCy9-R%3DhBNwwUptVk_f8keX40-9yHkpqstWMP3pLSKpLGw%40mail.gmail.com. >> For more options, visit https://groups.google.com/d/optout.
