syzbot


kernel BUG at arch/x86/kvm/mmu/mmu.c:LINE!

Status: fixed on 2020/02/18 14:31
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+c9d1fb51ac9d0d10c39d@syzkaller.appspotmail.com
Fix commit: 005ba37cb89b mm: thp: KVM: Explicitly check for THP when populating secondary MMU
First crash: 1653d, last: 1641d
Cause bisection: introduced by (bisect log) [merge commit]:
commit 73bf1fc58dc4376d0111a4c1c9eab27e2759f468
Author: David S. Miller <davem@davemloft.net>
Date: Tue May 22 18:44:20 2018 +0000

  Merge branch 'net-ipv6-Fix-route-append-and-replace-use-cases'

Crash: WARNING in __static_key_slow_dec_cpuslocked (log)
Repro: C syz .config
  
Discussions (2)
Title Replies (including bot) Last reply
[PATCH 00/14] KVM: x86/mmu: Huge page fixes, cleanup, and DAX 22 (22) 2020/01/21 15:12
kernel BUG at arch/x86/kvm/mmu/mmu.c:LINE! 2 (3) 2019/12/18 06:40
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream kernel BUG at arch/x86/kvm/mmu/mmu.c:LINE! (2) kvm C done 46328 1455d 1487d 15/27 fixed on 2020/07/17 17:58

Sample crash report:
------------[ cut here ]------------
kernel BUG at arch/x86/kvm/mmu/mmu.c:3416!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 9988 Comm: syz-executor218 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:transparent_hugepage_adjust+0x4c8/0x550 arch/x86/kvm/mmu/mmu.c:3416
Code: ff ff e8 eb 5d 5e 00 48 8b 45 b8 48 83 e8 01 48 89 45 c8 e9 a3 fd ff ff 48 89 df e8 c2 f8 9b 00 e9 7b fb ff ff e8 c8 5d 5e 00 <0f> 0b 48 8b 7d c8 e8 ad f8 9b 00 e9 ba fc ff ff 49 8d 7f 30 e8 7f
RSP: 0018:ffffc90001f27678 EFLAGS: 00010293
RAX: ffff8880a875a200 RBX: ffffc90001f27768 RCX: ffffffff8116cc87
RDX: 0000000000000000 RSI: ffffffff8116cdc8 RDI: 0000000000000007
RBP: ffffc90001f276c0 R08: ffff8880a875a200 R09: ffffed1010d79682
R10: ffffed1010d79681 R11: ffff888086bcb40b R12: 00000000000001d3
R13: 0000000000094dd3 R14: 0000000000094dd1 R15: 0000000000000000
FS:  0000000000fff880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009af1b000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 tdp_page_fault+0x580/0x6a0 arch/x86/kvm/mmu/mmu.c:4315
 kvm_mmu_page_fault+0x1dd/0x1800 arch/x86/kvm/mmu/mmu.c:5539
 handle_ept_violation+0x259/0x560 arch/x86/kvm/vmx/vmx.c:5163
 vmx_handle_exit+0x29f/0x1730 arch/x86/kvm/vmx/vmx.c:5921
 vcpu_enter_guest+0x334f/0x6110 arch/x86/kvm/x86.c:8290
 vcpu_run arch/x86/kvm/x86.c:8354 [inline]
 kvm_arch_vcpu_ioctl_run+0x430/0x17b0 arch/x86/kvm/x86.c:8561
 kvm_vcpu_ioctl+0x4dc/0xfc0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2847
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:545 [inline]
 do_vfs_ioctl+0x977/0x14e0 fs/ioctl.c:732
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:749
 __do_sys_ioctl fs/ioctl.c:756 [inline]
 __se_sys_ioctl fs/ioctl.c:754 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:754
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x440359
Code: 18 89 d0 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 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 fb 13 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffc16334278 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440359
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 00000000006ca018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 00000000004002c8 R11: 0000000000000246 R12: 0000000000401be0
R13: 0000000000401c70 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
---[ end trace e1a5b9c09fef2e33 ]---
RIP: 0010:transparent_hugepage_adjust+0x4c8/0x550 arch/x86/kvm/mmu/mmu.c:3416
Code: ff ff e8 eb 5d 5e 00 48 8b 45 b8 48 83 e8 01 48 89 45 c8 e9 a3 fd ff ff 48 89 df e8 c2 f8 9b 00 e9 7b fb ff ff e8 c8 5d 5e 00 <0f> 0b 48 8b 7d c8 e8 ad f8 9b 00 e9 ba fc ff ff 49 8d 7f 30 e8 7f
RSP: 0018:ffffc90001f27678 EFLAGS: 00010293
RAX: ffff8880a875a200 RBX: ffffc90001f27768 RCX: ffffffff8116cc87
RDX: 0000000000000000 RSI: ffffffff8116cdc8 RDI: 0000000000000007
RBP: ffffc90001f276c0 R08: ffff8880a875a200 R09: ffffed1010d79682
R10: ffffed1010d79681 R11: ffff888086bcb40b R12: 00000000000001d3
R13: 0000000000094dd3 R14: 0000000000094dd1 R15: 0000000000000000
FS:  0000000000fff880(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009af1b000 CR4: 00000000001426f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/12/13 04:34 upstream ae4b064e2a61 08003f64 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2019/12/12 22:39 upstream ae4b064e2a61 08003f64 .config console log report syz C ci-upstream-kasan-gce-root
2019/12/12 15:54 upstream 687dec9b9459 d973f528 .config console log report syz C ci-upstream-kasan-gce
2019/12/12 20:43 upstream ae4b064e2a61 08003f64 .config console log report syz C ci-upstream-kasan-gce-386
2019/12/24 05:52 linux-next 7ddd09fc4b74 be5c2c81 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/12/12 15:19 upstream 687dec9b9459 d973f528 .config console log report ci-upstream-kasan-gce
* Struck through repros no longer work on HEAD.