* kernel BUG at arch/x86/kvm/x86.c:LINE! (2)
@ 2018-10-10 7:52 syzbot
2018-10-10 12:33 ` syzbot
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: syzbot @ 2018-10-10 7:52 UTC (permalink / raw)
To: bp, hpa, kvm, linux-kernel, mingo, pbonzini, rkrcmar,
syzkaller-bugs, tglx, x86
Hello,
syzbot found the following crash on:
HEAD commit: 64c5e530ac2c Merge tag 'arc-4.19-rc8' of git://git.kernel...
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=167a4e85400000
kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d
dashboard link: https://syzkaller.appspot.com/bug?extid=f9b42efadea9f5453100
compiler: gcc (GCC) 8.0.1 20180413 (experimental)
userspace arch: i386
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+f9b42efadea9f5453100@syzkaller.appspotmail.com
Use struct sctp_sack_info instead
sctp: [Deprecated]: syz-executor0 (pid 11077) Use of struct
sctp_assoc_value in delayed_ack socket option.
Use struct sctp_sack_info instead
audit: type=1326 audit(1539141761.977:32): auid=4294967295 uid=0 gid=0
ses=4294967295 subj==unconfined pid=11031 comm="syz-executor2"
exe="/root/syz-executor2" sig=9 arch=40000003 syscall=265 compat=1
ip=0xf7fecca9 code=0x0
------------[ cut here ]------------
kernel BUG at arch/x86/kvm/x86.c:353!
------------[ cut here ]------------
kernel BUG at arch/x86/kvm/x86.c:353!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 11079 Comm: syz-executor2 Not tainted 4.19.0-rc7+ #178
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353
Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f
5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44
00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54
RSP: 0018:ffff8801dae07bd8 EFLAGS: 00010006
RAX: ffff8801cc2f2180 RBX: 1ffff1003b5c0f7f RCX: ffffffff81385bcc
RDX: 0000000000010000 RSI: ffffffff810bd1f9 RDI: ffff8801dae07c18
RBP: ffff8801dae07bd8 R08: ffff8801cc2f2180 R09: ffffed003b5c5ba0
R10: ffffed003b5c5ba0 R11: ffff8801dae2dd07 R12: ffff8801dae07c58
R13: dffffc0000000000 R14: ffff8801beccc000 R15: ffff8801dae07c18
FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000f5fa6b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffff8801dae07c18 CR3: 00000001cc8d1000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<IRQ>
kvm_fastop_exception+0x50b/0x5455
loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline]
__loaded_vmcs_clear+0x2d6/0x690 arch/x86/kvm/vmx.c:2212
flush_smp_call_function_queue+0x1d2/0x640 kernel/smp.c:243
generic_smp_call_function_single_interrupt+0x13/0x2b kernel/smp.c:192
smp_call_function_single_interrupt+0x12f/0x650 arch/x86/kernel/smp.c:296
call_function_single_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886
</IRQ>
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline]
RIP: 0010:preempt_schedule_irq+0x7d/0x110 kernel/sched/core.c:3699
Code: 00 e8 87 6a a6 f9 e8 c2 d8 d5 f9 4c 89 f0 48 c1 e8 03 42 80 3c 20 00
75 7b 48 83 3d 14 ea 82 01 00 74 61 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00
e8 f9 d1 ff ff 41 80 7d 00 00 75 6a 48 83 3d ea e9
RSP: 0018:ffff88018b397160 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff04
RAX: 1ffffffff1263e53 RBX: 0000000000000000 RCX: ffffc9000628e000
RDX: 0000000000000004 RSI: ffffffff8184e1e4 RDI: ffffffff896fe100
RBP: ffff88018b397188 R08: ffff8801cc2f2180 R09: ffffed003b5c5979
R10: ffffed003b5c5979 R11: ffff8801dae2cbcb R12: dffffc0000000000
R13: fffffbfff1263e52 R14: ffffffff8931f298 R15: ffffffff8931f290
retint_kernel+0x1b/0x2d
RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline]
RIP: 0010:cond_local_irq_enable arch/x86/kernel/traps.c:80 [inline]
RIP: 0010:do_error_trap+0x270/0x4d0 arch/x86/kernel/traps.c:301
Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 4f 02 00 00 48 83
3d 55 6a 07 08 00 0f 84 46 01 00 00 fb 66 0f 1f 44 00 00 <e9> b8 fe ff ff
31 c0 41 b8 01 00 00 00 48 ba 00 00 00 00 00 fc ff
RSP: 0018:ffff88018b397248 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02
RAX: dffffc0000000000 RBX: ffff88018b397398 RCX: ffffc9000628e000
RDX: 1ffffffff1263e53 RSI: ffffffff8184e1e4 RDI: ffffffff8931f298
RBP: ffff88018b397378 R08: ffff8801cc2f2180 R09: 0000000000000001
R10: fffffbfff12720fc R11: 0000000000000000 R12: 0000000000000006
R13: ffff88018b397350 R14: 0000000000000004 R15: 1ffff10031672e4e
do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316
invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993
RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353
Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f
5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44
00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54
RSP: 0018:ffff88018b397448 EFLAGS: 00010212
RAX: 0000000000040000 RBX: 1ffff10031672e8d RCX: ffffc9000628e000
RDX: 0000000000000417 RSI: ffffffff810bd1f9 RDI: ffff88018b397488
RBP: ffff88018b397448 R08: ffff8801cc2f2180 R09: ffff8801c308d000
R10: ffffed0038611bff R11: ffff8801c308dfff R12: ffff88018b3974c8
R13: dffffc0000000000 R14: ffff8801c308d000 R15: ffff88018b397488
kvm_fastop_exception+0x50b/0x5455
loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline]
alloc_loaded_vmcs+0x7f/0x280 arch/x86/kvm/vmx.c:4766
vmx_create_vcpu+0x20e/0x25e0 arch/x86/kvm/vmx.c:11025
kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8471
kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476
[inline]
kvm_vm_ioctl+0x470/0x1d40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977
kvm_vm_compat_ioctl+0x143/0x430
arch/x86/kvm/../../../virt/kvm/kvm_main.c:3170
__do_compat_sys_ioctl fs/compat_ioctl.c:1419 [inline]
__se_compat_sys_ioctl fs/compat_ioctl.c:1365 [inline]
__ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:1365
do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline]
do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397
entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139
RIP: 0023:0xf7fecca9
Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 0c 24 c3 8b 1c 24 c3 90 90
90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90
90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 002b:00000000f5fa60cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036
RAX: ffffffffffffffda RBX: 000000000000000c RCX: 000000000000ae41
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace 1c8fec48833612c0 ]---
RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353
Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f
5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44
00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54
RSP: 0018:ffff8801dae07bd8 EFLAGS: 00010006
RAX: ffff8801cc2f2180 RBX: 1ffff1003b5c0f7f RCX: ffffffff81385bcc
RDX: 0000000000010000 RSI: ffffffff810bd1f9 RDI: ffff8801dae07c18
RBP: ffff8801dae07bd8 R08: ffff8801cc2f2180 R09: ffffed003b5c5ba0
R10: ffffed003b5c5ba0 R11: ffff8801dae2dd07 R12: ffff8801dae07c58
R13: dffffc0000000000 R14: ffff8801beccc000 R15: ffff8801dae07c18
FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000f5fa6b40
CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: ffff8801dae07c18 CR3: 00000001cc8d1000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
---
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@googlegroups.com.
syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with
syzbot.
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: kernel BUG at arch/x86/kvm/x86.c:LINE! (2) 2018-10-10 7:52 kernel BUG at arch/x86/kvm/x86.c:LINE! (2) syzbot @ 2018-10-10 12:33 ` syzbot 2018-10-10 20:34 ` syzbot 2018-10-11 2:57 ` Du Changbin 2 siblings, 0 replies; 6+ messages in thread From: syzbot @ 2018-10-10 12:33 UTC (permalink / raw) To: bp, hpa, kvm, linux-kernel, mingo, pbonzini, rkrcmar, syzkaller-bugs, tglx, x86 syzbot has found a reproducer for the following crash on: HEAD commit: 3d647e62686f Merge tag 's390-4.19-4' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=15fc834e400000 kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d dashboard link: https://syzkaller.appspot.com/bug?extid=f9b42efadea9f5453100 compiler: gcc (GCC) 8.0.1 20180413 (experimental) userspace arch: i386 syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1271be91400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+f9b42efadea9f5453100@syzkaller.appspotmail.com IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready 8021q: adding VLAN 0 to HW filter on device team0 8021q: adding VLAN 0 to HW filter on device team0 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/x86.c:353! invalid opcode: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 7328 Comm: syz-executor4 Not tainted 4.19.0-rc7+ #179 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 kobject: 'loop3' (0000000004d24d87): kobject_uevent_env RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 kobject: 'loop3' (0000000004d24d87): fill_kobj_path: path = '/devices/virtual/block/loop3' Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 RSP: 0018:ffff8801ce167340 EFLAGS: 00010093 RAX: ffff8801cd750440 RBX: 1ffff10039c2ce6c RCX: ffffffff81385bcc RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801ce167380 kobject: 'kvm' (0000000063fb9207): kobject_uevent_env RBP: ffff8801ce167340 R08: ffff8801cd750440 R09: fffff520003f4047 R10: fffff520003f4047 R11: ffffc90001fa023b R12: ffff8801ce1673c0 R13: dffffc0000000000 R14: ffff8801d7dc9000 R15: ffff8801ce167380 FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:0000000009b8d900 kobject: 'kvm' (0000000063fb9207): fill_kobj_path: path = '/devices/virtual/misc/kvm' CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 CR2: ffff8801ce167380 CR3: 00000001d5af7000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kobject: 'kvm' (0000000063fb9207): kobject_uevent_env kvm_fastop_exception+0x50b/0x5455 ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/x86.c:353! loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline] __loaded_vmcs_clear+0x2d6/0x690 arch/x86/kvm/vmx.c:2212 kobject: 'kvm' (0000000063fb9207): fill_kobj_path: path = '/devices/virtual/misc/kvm' generic_exec_single+0x373/0x5f0 kernel/smp.c:153 smp_call_function_single+0x1b2/0x660 kernel/smp.c:299 loaded_vmcs_clear arch/x86/kvm/vmx.c:2221 [inline] free_loaded_vmcs+0x13c/0x1b0 arch/x86/kvm/vmx.c:4746 vmx_free_vcpu+0x204/0x300 arch/x86/kvm/vmx.c:10982 kvm_arch_vcpu_free arch/x86/kvm/x86.c:8457 [inline] kvm_free_vcpus arch/x86/kvm/x86.c:8909 [inline] kvm_arch_destroy_vm+0x365/0x7c0 arch/x86/kvm/x86.c:9006 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:752 [inline] kvm_put_kvm+0x6c8/0xff0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:773 kvm_vcpu_release+0x7b/0xa0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2407 __fput+0x385/0xa30 fs/file_table.c:278 ____fput+0x15/0x20 fs/file_table.c:309 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:193 [inline] exit_to_usermode_loop+0x318/0x380 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_32_irqs_on arch/x86/entry/common.c:341 [inline] do_fast_syscall_32+0xcd5/0xfb2 arch/x86/entry/common.c:397 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7efdca9 Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 0c 24 c3 8b 1c 24 c3 90 90 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 002b:000000000845fdac EFLAGS: 00000216 ORIG_RAX: 0000000000000006 RAX: 0000000000000000 RBX: 0000000000000007 RCX: 0000000000000000 RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Modules linked in: ---[ end trace 2ea88a0e29b1263b ]--- invalid opcode: 0000 [#2] PREEMPT SMP KASAN CPU: 1 PID: 7351 Comm: syz-executor3 Tainted: G D 4.19.0-rc7+ #179 RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 RSP: 0018:ffff8801ce167340 EFLAGS: 00010093 Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 RSP: 0018:ffff8801cd357448 EFLAGS: 00010293 RAX: ffff8801cd750440 RBX: 1ffff10039c2ce6c RCX: ffffffff81385bcc RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801ce167380 RAX: ffff8801bbcea080 RBX: 1ffff10039a6ae8d RCX: ffffffff81385bcc RBP: ffff8801ce167340 R08: ffff8801cd750440 R09: fffff520003f4047 RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801cd357488 R10: fffff520003f4047 R11: ffffc90001fa023b R12: ffff8801ce1673c0 RBP: ffff8801cd357448 R08: ffff8801bbcea080 R09: ffff8801ce981000 R13: dffffc0000000000 R14: ffff8801d7dc9000 R15: ffff8801ce167380 R10: ffffed0039d303ff R11: ffff8801ce981fff R12: ffff8801cd3574c8 FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:0000000009b8d900 R13: dffffc0000000000 R14: ffff8801ce981000 R15: ffff8801cd357488 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 FS: 0000000000000000(0000) GS:ffff8801daf00000(0063) knlGS:00000000f7ef6b40 CR2: ffff8801ce167380 CR3: 00000001d5af7000 CR4: 00000000001426f0 CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 CR2: 00007f1f49c6b000 CR3: 00000001cf36e000 CR4: 00000000001426e0 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG at arch/x86/kvm/x86.c:LINE! (2) 2018-10-10 7:52 kernel BUG at arch/x86/kvm/x86.c:LINE! (2) syzbot 2018-10-10 12:33 ` syzbot @ 2018-10-10 20:34 ` syzbot 2018-10-11 2:57 ` Du Changbin 2 siblings, 0 replies; 6+ messages in thread From: syzbot @ 2018-10-10 20:34 UTC (permalink / raw) To: bp, hpa, kvm, linux-kernel, mingo, pbonzini, rkrcmar, syzkaller-bugs, tglx, x86 syzbot has found a reproducer for the following crash on: HEAD commit: 3d647e62686f Merge tag 's390-4.19-4' of git://git.kernel.o.. git tree: upstream console output: https://syzkaller.appspot.com/x/log.txt?x=11be99a1400000 kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d dashboard link: https://syzkaller.appspot.com/bug?extid=f9b42efadea9f5453100 compiler: gcc (GCC) 8.0.1 20180413 (experimental) syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1057d809400000 C reproducer: https://syzkaller.appspot.com/x/repro.c?x=131e37c9400000 IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+f9b42efadea9f5453100@syzkaller.appspotmail.com audit: type=1400 audit(1539203398.925:36): avc: denied { map } for pid=5855 comm="syz-executor775" path="/root/syz-executor775778886" dev="sda1" ino=16481 scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:user_home_t:s0 tclass=file permissive=1 L1TF CPU bug present and SMT on, data leak possible. See CVE-2018-3646 and https://www.kernel.org/doc/html/latest/admin-guide/l1tf.html for details. ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/x86.c:353! invalid opcode: 0000 [#1] PREEMPT SMP KASAN kobject: 'kvm' (00000000154a8e53): fill_kobj_path: path = '/devices/virtual/misc/kvm' CPU: 0 PID: 5871 Comm: syz-executor775 Not tainted 4.19.0-rc7+ #55 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 RSP: 0018:ffff8801c428f388 EFLAGS: 00010293 RAX: ffff8801c5676380 RBX: ffff8801c428f408 RCX: ffffffff81385bcc RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801c428f3c8 RBP: ffff8801c428f388 R08: ffff8801c5676380 R09: fffff520003dea46 R10: fffff520003dea46 R11: ffffc90001ef5237 R12: 1ffff10038851e75 R13: ffff8801c428f3c8 R14: ffff8801c481d000 R15: ffff8801c7cdb000 FS: 00007f4825a83700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c428f3c8 CR3: 00000001c4e7c000 CR4: 00000000001426f0 kobject: 'kvm' (00000000154a8e53): kobject_uevent_env DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kvm_fastop_exception+0x523/0x5455 kobject: 'kvm' (00000000154a8e53): kobject_uevent_env kobject: 'kvm' (00000000154a8e53): fill_kobj_path: path = '/devices/virtual/misc/kvm' vmx_vcpu_load+0x496/0x1030 arch/x86/kvm/vmx.c:3079 ------------[ cut here ]------------ kernel BUG at arch/x86/kvm/x86.c:353! kvm_arch_vcpu_load+0x247/0x970 arch/x86/kvm/x86.c:3109 vcpu_load+0x35/0x70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:164 kvm_arch_vcpu_setup+0x1d/0x40 arch/x86/kvm/x86.c:8479 kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2484 [inline] kvm_vm_ioctl+0x107d/0x1d40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977 vfs_ioctl fs/ioctl.c:46 [inline] file_ioctl fs/ioctl.c:501 [inline] do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702 __do_sys_ioctl fs/ioctl.c:709 [inline] __se_sys_ioctl fs/ioctl.c:707 [inline] __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x446df9 Code: e8 dc e6 ff ff 48 83 c4 18 c3 0f 1f 80 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 4b 07 fc ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f4825a82da8 EFLAGS: 00000297 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00000000006dcc48 RCX: 0000000000446df9 RDX: 0000000000000000 RSI: 000000000000ae41 RDI: 0000000000000004 RBP: 00000000006dcc40 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000297 R12: 00000000006dcc4c R13: 6d766b2f7665642f R14: 00007f4825a839c0 R15: 00000000006dcd4c Modules linked in: invalid opcode: 0000 [#2] PREEMPT SMP KASAN ---[ end trace 646ff58a828dac28 ]--- CPU: 1 PID: 5870 Comm: syz-executor775 Tainted: G D 4.19.0-rc7+ #55 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 RSP: 0018:ffff8801c4347380 EFLAGS: 00010093 RAX: ffff8801c5662340 RBX: 1ffff10038868e74 RCX: ffffffff81385bcc RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801c43473c0 RBP: ffff8801c4347380 R08: ffff8801c5662340 R09: fffff520003e0247 Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 R10: fffff520003e0247 R11: ffffc90001f0123b R12: ffff8801c4347400 RSP: 0018:ffff8801c428f388 EFLAGS: 00010293 R13: dffffc0000000000 R14: ffff8801be3c2000 R15: ffff8801c43473c0 FS: 00000000010fc880(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffff8801c43473c0 CR3: 00000001c44d8000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 RAX: ffff8801c5676380 RBX: ffff8801c428f408 RCX: ffffffff81385bcc Call Trace: RDX: 0000000000000000 RSI: ffffffff810bd1f9 RDI: ffff8801c428f3c8 kvm_fastop_exception+0x50b/0x5455 RBP: ffff8801c428f388 R08: ffff8801c5676380 R09: fffff520003dea46 R10: fffff520003dea46 R11: ffffc90001ef5237 R12: 1ffff10038851e75 loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline] __loaded_vmcs_clear+0x2d6/0x690 arch/x86/kvm/vmx.c:2212 R13: ffff8801c428f3c8 R14: ffff8801c481d000 R15: ffff8801c7cdb000 FS: 00007f4825a83700(0000) GS:ffff8801dae00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 generic_exec_single+0x373/0x5f0 kernel/smp.c:153 CR2: ffff8801c428f3c8 CR3: 00000001c4e7c000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 smp_call_function_single+0x1b2/0x660 kernel/smp.c:299 ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG at arch/x86/kvm/x86.c:LINE! (2) 2018-10-10 7:52 kernel BUG at arch/x86/kvm/x86.c:LINE! (2) syzbot 2018-10-10 12:33 ` syzbot 2018-10-10 20:34 ` syzbot @ 2018-10-11 2:57 ` Du Changbin 2018-10-11 14:32 ` Paolo Bonzini 2 siblings, 1 reply; 6+ messages in thread From: Du Changbin @ 2018-10-11 2:57 UTC (permalink / raw) To: syzbot Cc: bp, hpa, kvm, linux-kernel, mingo, pbonzini, rkrcmar, syzkaller-bugs, tglx, x86, changbin.du I think the issue is that using vmx instructions after vmx off. The scenario is: 1. kernel is rebooting and vmx is turned off by notification handler kvm_reboot(), and 'kvm_rebooting' is set. 2. But there is a pending KVM_CREATE_VCPU ioctl which will invoke vmcs_clear()-> ____kvm_handle_fault_on_reboot()->kvm_spurious_fault()->BUG(). Need to improve the handler for such case so won't hang kernel. On Wed, Oct 10, 2018 at 12:52:03AM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 64c5e530ac2c Merge tag 'arc-4.19-rc8' of git://git.kernel... > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=167a4e85400000 > kernel config: https://syzkaller.appspot.com/x/.config?x=88e9a8a39dc0be2d > dashboard link: https://syzkaller.appspot.com/bug?extid=f9b42efadea9f5453100 > compiler: gcc (GCC) 8.0.1 20180413 (experimental) > userspace arch: i386 > > 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+f9b42efadea9f5453100@syzkaller.appspotmail.com > > Use struct sctp_sack_info instead > sctp: [Deprecated]: syz-executor0 (pid 11077) Use of struct sctp_assoc_value > in delayed_ack socket option. > Use struct sctp_sack_info instead > audit: type=1326 audit(1539141761.977:32): auid=4294967295 uid=0 gid=0 > ses=4294967295 subj==unconfined pid=11031 comm="syz-executor2" > exe="/root/syz-executor2" sig=9 arch=40000003 syscall=265 compat=1 > ip=0xf7fecca9 code=0x0 > ------------[ cut here ]------------ > kernel BUG at arch/x86/kvm/x86.c:353! > ------------[ cut here ]------------ > kernel BUG at arch/x86/kvm/x86.c:353! > invalid opcode: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 11079 Comm: syz-executor2 Not tainted 4.19.0-rc7+ #178 > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > Google 01/01/2011 > RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 > Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f > 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 > 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 > RSP: 0018:ffff8801dae07bd8 EFLAGS: 00010006 > RAX: ffff8801cc2f2180 RBX: 1ffff1003b5c0f7f RCX: ffffffff81385bcc > RDX: 0000000000010000 RSI: ffffffff810bd1f9 RDI: ffff8801dae07c18 > RBP: ffff8801dae07bd8 R08: ffff8801cc2f2180 R09: ffffed003b5c5ba0 > R10: ffffed003b5c5ba0 R11: ffff8801dae2dd07 R12: ffff8801dae07c58 > R13: dffffc0000000000 R14: ffff8801beccc000 R15: ffff8801dae07c18 > FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000f5fa6b40 > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > CR2: ffff8801dae07c18 CR3: 00000001cc8d1000 CR4: 00000000001426f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > Call Trace: > <IRQ> > kvm_fastop_exception+0x50b/0x5455 > loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline] > __loaded_vmcs_clear+0x2d6/0x690 arch/x86/kvm/vmx.c:2212 > flush_smp_call_function_queue+0x1d2/0x640 kernel/smp.c:243 > generic_smp_call_function_single_interrupt+0x13/0x2b kernel/smp.c:192 > smp_call_function_single_interrupt+0x12f/0x650 arch/x86/kernel/smp.c:296 > call_function_single_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:886 > </IRQ> > RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline] > RIP: 0010:preempt_schedule_irq+0x7d/0x110 kernel/sched/core.c:3699 > Code: 00 e8 87 6a a6 f9 e8 c2 d8 d5 f9 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 > 75 7b 48 83 3d 14 ea 82 01 00 74 61 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 > f9 d1 ff ff 41 80 7d 00 00 75 6a 48 83 3d ea e9 > RSP: 0018:ffff88018b397160 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff04 > RAX: 1ffffffff1263e53 RBX: 0000000000000000 RCX: ffffc9000628e000 > RDX: 0000000000000004 RSI: ffffffff8184e1e4 RDI: ffffffff896fe100 > RBP: ffff88018b397188 R08: ffff8801cc2f2180 R09: ffffed003b5c5979 > R10: ffffed003b5c5979 R11: ffff8801dae2cbcb R12: dffffc0000000000 > R13: fffffbfff1263e52 R14: ffffffff8931f298 R15: ffffffff8931f290 > retint_kernel+0x1b/0x2d > RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:798 [inline] > RIP: 0010:cond_local_irq_enable arch/x86/kernel/traps.c:80 [inline] > RIP: 0010:do_error_trap+0x270/0x4d0 arch/x86/kernel/traps.c:301 > Code: 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 4f 02 00 00 48 83 > 3d 55 6a 07 08 00 0f 84 46 01 00 00 fb 66 0f 1f 44 00 00 <e9> b8 fe ff ff 31 > c0 41 b8 01 00 00 00 48 ba 00 00 00 00 00 fc ff > RSP: 0018:ffff88018b397248 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 > RAX: dffffc0000000000 RBX: ffff88018b397398 RCX: ffffc9000628e000 > RDX: 1ffffffff1263e53 RSI: ffffffff8184e1e4 RDI: ffffffff8931f298 > RBP: ffff88018b397378 R08: ffff8801cc2f2180 R09: 0000000000000001 > R10: fffffbfff12720fc R11: 0000000000000000 R12: 0000000000000006 > R13: ffff88018b397350 R14: 0000000000000004 R15: 1ffff10031672e4e > do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:316 > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:993 > RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 > Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f > 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 > 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 > RSP: 0018:ffff88018b397448 EFLAGS: 00010212 > RAX: 0000000000040000 RBX: 1ffff10031672e8d RCX: ffffc9000628e000 > RDX: 0000000000000417 RSI: ffffffff810bd1f9 RDI: ffff88018b397488 > RBP: ffff88018b397448 R08: ffff8801cc2f2180 R09: ffff8801c308d000 > R10: ffffed0038611bff R11: ffff8801c308dfff R12: ffff88018b3974c8 > R13: dffffc0000000000 R14: ffff8801c308d000 R15: ffff88018b397488 > kvm_fastop_exception+0x50b/0x5455 > loaded_vmcs_init arch/x86/kvm/vmx.c:2129 [inline] > alloc_loaded_vmcs+0x7f/0x280 arch/x86/kvm/vmx.c:4766 > vmx_create_vcpu+0x20e/0x25e0 arch/x86/kvm/vmx.c:11025 > kvm_arch_vcpu_create+0xe5/0x220 arch/x86/kvm/x86.c:8471 > kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:2476 > [inline] > kvm_vm_ioctl+0x470/0x1d40 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2977 > kvm_vm_compat_ioctl+0x143/0x430 > arch/x86/kvm/../../../virt/kvm/kvm_main.c:3170 > __do_compat_sys_ioctl fs/compat_ioctl.c:1419 [inline] > __se_compat_sys_ioctl fs/compat_ioctl.c:1365 [inline] > __ia32_compat_sys_ioctl+0x20e/0x630 fs/compat_ioctl.c:1365 > do_syscall_32_irqs_on arch/x86/entry/common.c:326 [inline] > do_fast_syscall_32+0x34d/0xfb2 arch/x86/entry/common.c:397 > entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 > RIP: 0023:0xf7fecca9 > Code: 85 d2 74 02 89 0a 5b 5d c3 8b 04 24 c3 8b 0c 24 c3 8b 1c 24 c3 90 90 > 90 90 90 90 90 90 90 90 90 90 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 > 90 90 eb 0d 90 90 90 90 90 90 90 90 90 90 90 90 > RSP: 002b:00000000f5fa60cc EFLAGS: 00000296 ORIG_RAX: 0000000000000036 > RAX: ffffffffffffffda RBX: 000000000000000c RCX: 000000000000ae41 > RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 > RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 > R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 > Modules linked in: > ---[ end trace 1c8fec48833612c0 ]--- > RIP: 0010:kvm_spurious_fault+0x9/0x10 arch/x86/kvm/x86.c:353 > Code: 45 10 50 e8 e9 44 7c 00 58 5a 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f > 5d c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 e8 97 03 73 00 <0f> 0b 0f 1f 44 00 > 00 55 48 89 e5 41 57 41 56 41 55 41 89 fd 41 54 > RSP: 0018:ffff8801dae07bd8 EFLAGS: 00010006 > RAX: ffff8801cc2f2180 RBX: 1ffff1003b5c0f7f RCX: ffffffff81385bcc > RDX: 0000000000010000 RSI: ffffffff810bd1f9 RDI: ffff8801dae07c18 > RBP: ffff8801dae07bd8 R08: ffff8801cc2f2180 R09: ffffed003b5c5ba0 > R10: ffffed003b5c5ba0 R11: ffff8801dae2dd07 R12: ffff8801dae07c58 > R13: dffffc0000000000 R14: ffff8801beccc000 R15: ffff8801dae07c18 > FS: 0000000000000000(0000) GS:ffff8801dae00000(0063) knlGS:00000000f5fa6b40 > CS: 0010 DS: 002b ES: 002b CR0: 0000000080050033 > CR2: ffff8801dae07c18 CR3: 00000001cc8d1000 CR4: 00000000001426f0 > DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 > DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 > > > --- > 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@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#bug-status-tracking for how to communicate with > syzbot. -- Thanks, Du Changbin ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG at arch/x86/kvm/x86.c:LINE! (2) 2018-10-11 2:57 ` Du Changbin @ 2018-10-11 14:32 ` Paolo Bonzini 2018-10-11 18:05 ` Dmitry Vyukov 0 siblings, 1 reply; 6+ messages in thread From: Paolo Bonzini @ 2018-10-11 14:32 UTC (permalink / raw) To: Du Changbin, syzbot Cc: bp, hpa, kvm, linux-kernel, mingo, rkrcmar, syzkaller-bugs, tglx, x86, changbin.du, Dmitry Vyukov On 11/10/2018 04:57, Du Changbin wrote: > I think the issue is that using vmx instructions after vmx off. The > scenario is: > 1. kernel is rebooting and vmx is turned off by notification handler > kvm_reboot(), > and 'kvm_rebooting' is set. > 2. But there is a pending KVM_CREATE_VCPU ioctl which will invoke > vmcs_clear()-> > ____kvm_handle_fault_on_reboot()->kvm_spurious_fault()->BUG(). > > Need to improve the handler for such case so won't hang kernel. Why would the kernel be rebooting, given the reproducer (listed below my signature, or at https://syzkaller.appspot.com/x/repro.c?x=131e37c9400000)? I think this is a duplicate of WARNING: refcount bug in kvm_vm_ioctl BUG: unable to handle kernel paging request in refcount_inc_not_zero_checked In all cases the refcounts seem to be broken, and kvm_destroy_kvm is called prematurely (which in this case results in hardware_disable_all being called, so that the vmclear fails). Dmitry, have such bugs been reported for subsystems other than KVM? Paolo #syz dup: WARNING: refcount bug in kvm_vm_ioctl > # See https://goo.gl/kgGztJ for information about syzkaller reproducers. > #{"threaded":true,"repeat":true,"procs":6,"sandbox":"","fault_call":-1,"tmpdir":true} > r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000080)='/dev/kvm\x00', 0x0, 0x0) > r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) > r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) > ioctl$KVM_SET_VCPU_EVENTS(r2, 0x4040aea0, &(0x7f0000000000)={0x5, 0x7, 0x40, 0x0, 0x0, 0x0, 0x0, 0x492, 0x5, 0x1, 0xffff, 0x0, 0x0, 0xef, 0x100000000, 0x0, 0x100}) > ioctl$KVM_SET_USER_MEMORY_REGION(r1, 0x4020ae46, &(0x7f0000000040)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000ffe000/0x2000)=nil}) > ioctl$KVM_SET_SREGS(r2, 0x4138ae84, &(0x7f00000003c0)={{}, {}, {}, {}, {}, {}, {}, {}, {}, {}, 0x8005001f, 0x0, 0x0, 0x28, 0x0, 0x6500}) > ioctl$KVM_RUN(r2, 0xae80, 0x0) ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: kernel BUG at arch/x86/kvm/x86.c:LINE! (2) 2018-10-11 14:32 ` Paolo Bonzini @ 2018-10-11 18:05 ` Dmitry Vyukov 0 siblings, 0 replies; 6+ messages in thread From: Dmitry Vyukov @ 2018-10-11 18:05 UTC (permalink / raw) To: Paolo Bonzini Cc: Du Changbin, syzbot, Borislav Petkov, H. Peter Anvin, KVM list, LKML, Ingo Molnar, Radim Krčmář, syzkaller-bugs, Thomas Gleixner, the arch/x86 maintainers, changbin.du On Thu, Oct 11, 2018 at 4:32 PM, Paolo Bonzini <pbonzini@redhat.com> wrote: > On 11/10/2018 04:57, Du Changbin wrote: >> I think the issue is that using vmx instructions after vmx off. The >> scenario is: >> 1. kernel is rebooting and vmx is turned off by notification handler >> kvm_reboot(), >> and 'kvm_rebooting' is set. >> 2. But there is a pending KVM_CREATE_VCPU ioctl which will invoke >> vmcs_clear()-> >> ____kvm_handle_fault_on_reboot()->kvm_spurious_fault()->BUG(). >> >> Need to improve the handler for such case so won't hang kernel. > > Why would the kernel be rebooting, given the reproducer (listed below my > signature, or at https://syzkaller.appspot.com/x/repro.c?x=131e37c9400000)? > > I think this is a duplicate of > > WARNING: refcount bug in kvm_vm_ioctl > BUG: unable to handle kernel paging request in > refcount_inc_not_zero_checked > > In all cases the refcounts seem to be broken, and kvm_destroy_kvm is > called prematurely (which in this case results in hardware_disable_all > being called, so that the vmclear fails). > > Dmitry, have such bugs been reported for subsystems other than KVM? We have _all_ types of bugs reported in _all_ subsystems. So you need to be more precise :) You can see all currently open bugs here: https://syzkaller.appspot.com/#upstream And here you can search over reports: https://groups.google.com/forum/#!forum/syzkaller-bugs E.g.: https://groups.google.com/forum/#!searchin/syzkaller-bugs/refcount_inc_not_zero_checked We had this recently, which is task_struct refcount bug: https://syzkaller.appspot.com/bug?id=e1854417677586ce3d00f498f19816cb4fd15676 but this seems to be related to rdma. And repro for this bug only deals with kvm. So my guess would be that this is a different bug in kvm. If you can reproduce it, then perhaps logging all refcount operation on the thing will help to find whoever releases a ref it does not own. > Paolo > > #syz dup: WARNING: refcount bug in kvm_vm_ioctl > >> # See https://goo.gl/kgGztJ for information about syzkaller reproducers. >> #{"threaded":true,"repeat":true,"procs":6,"sandbox":"","fault_call":-1,"tmpdir":true} >> r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000080)='/dev/kvm\x00', 0x0, 0x0) >> r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0) >> r2 = ioctl$KVM_CREATE_VCPU(r1, 0xae41, 0x0) >> ioctl$KVM_SET_VCPU_EVENTS(r2, 0x4040aea0, &(0x7f0000000000)={0x5, 0x7, 0x40, 0x0, 0x0, 0x0, 0x0, 0x492, 0x5, 0x1, 0xffff, 0x0, 0x0, 0xef, 0x100000000, 0x0, 0x100}) >> ioctl$KVM_SET_USER_MEMORY_REGION(r1, 0x4020ae46, &(0x7f0000000040)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000ffe000/0x2000)=nil}) >> ioctl$KVM_SET_SREGS(r2, 0x4138ae84, &(0x7f00000003c0)={{}, {}, {}, {}, {}, {}, {}, {}, {}, {}, 0x8005001f, 0x0, 0x0, 0x28, 0x0, 0x6500}) >> ioctl$KVM_RUN(r2, 0xae80, 0x0) ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2018-10-11 18:05 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2018-10-10 7:52 kernel BUG at arch/x86/kvm/x86.c:LINE! (2) syzbot 2018-10-10 12:33 ` syzbot 2018-10-10 20:34 ` syzbot 2018-10-11 2:57 ` Du Changbin 2018-10-11 14:32 ` Paolo Bonzini 2018-10-11 18:05 ` Dmitry Vyukov
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox