KMSAN: uninit-value in vmx_queue_exception

Status: auto-obsoleted due to no activity on 2022/12/09 22:15
Subsystems: kvm-x86
[Documentation on labels]
Reported-by: syzbot+788c6e0a154504bd4b99@syzkaller.appspotmail.com
First crash: 2845d, last: 2705d
▶ ▼ Discussions (3)
Title Replies (including bot) Last reply
Reminder: 25 open syzbot bugs in kvm subsystem 1 (1) 2019/07/24 01:43
Reminder: 25 open syzbot bugs in kvm subsystem 1 (1) 2019/06/24 05:21
KMSAN: uninit-value in vmx_queue_exception 0 (1) 2018/12/03 13:20
▶ ▼ Last patch testing requests (5)
Created Duration User Patch Repo Result
2022/12/09 21:31 21m retest repro https://github.com/google/kmsan.git master OK log
2022/12/09 20:31 21m retest repro https://github.com/google/kmsan.git master OK log
2022/08/31 17:27 5m retest repro https://github.com/google/kmsan.git master error
2022/08/31 14:27 5m retest repro https://github.com/google/kmsan.git master error
2020/09/18 20:06 17m anant.thazhemadam@gmail.com https://github.com/google/kmsan.git master OK

Sample crash report:
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.
==================================================================
BUG: KMSAN: uninit-value in __vmcs_writel arch/x86/kvm/vmx.c:2399 [inline]
BUG: KMSAN: uninit-value in vmcs_write32 arch/x86/kvm/vmx.c:2420 [inline]
BUG: KMSAN: uninit-value in vmx_queue_exception+0x757/0x920 arch/x86/kvm/vmx.c:3352
CPU: 0 PID: 6638 Comm: syz-executor166 Not tainted 4.20.0-rc3+ #89
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x32d/0x480 lib/dump_stack.c:113
 kmsan_report+0x19f/0x300 mm/kmsan/kmsan.c:911
 __msan_warning+0x76/0xc0 mm/kmsan/kmsan_instr.c:415
 __vmcs_writel arch/x86/kvm/vmx.c:2399 [inline]
 vmcs_write32 arch/x86/kvm/vmx.c:2420 [inline]
 vmx_queue_exception+0x757/0x920 arch/x86/kvm/vmx.c:3352
 inject_pending_event arch/x86/kvm/x86.c:7146 [inline]
 vcpu_enter_guest arch/x86/kvm/x86.c:7641 [inline]
 vcpu_run arch/x86/kvm/x86.c:7872 [inline]
 kvm_arch_vcpu_ioctl_run+0x7d81/0x12040 arch/x86/kvm/x86.c:8072
 kvm_vcpu_ioctl+0xfb1/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
 do_vfs_ioctl+0xfbc/0x2f70 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x442a39
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 1b 0c fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007ffef8ea1048 EFLAGS: 00000217 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000442a39
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00000000006cd018 R08: 00000000004002c8 R09: 00000000004002c8
R10: 0000000020014000 R11: 0000000000000217 R12: 0000000000403ae0
R13: 0000000000403b70 R14: 0000000000000000 R15: 0000000000000000

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:252 [inline]
 kmsan_save_stack mm/kmsan/kmsan.c:267 [inline]
 kmsan_internal_chain_origin+0x136/0x240 mm/kmsan/kmsan.c:569
 __msan_chain_origin+0x6d/0xb0 mm/kmsan/kmsan_instr.c:292
 kvm_multiple_exception arch/x86/kvm/x86.c:483 [inline]
 kvm_queue_exception_e_p arch/x86/kvm/x86.c:554 [inline]
 kvm_inject_page_fault+0xa60/0xef0 arch/x86/kvm/x86.c:578
 nested_vmx_get_vmptr+0x36f/0x3d0 arch/x86/kvm/vmx.c:8264
 handle_vmon+0x5ea/0xe70 arch/x86/kvm/vmx.c:8387
 vmx_handle_exit+0x21bd/0xb980 arch/x86/kvm/vmx.c:10600
 vcpu_enter_guest arch/x86/kvm/x86.c:7809 [inline]
 vcpu_run arch/x86/kvm/x86.c:7872 [inline]
 kvm_arch_vcpu_ioctl_run+0xaeee/0x12040 arch/x86/kvm/x86.c:8072
 kvm_vcpu_ioctl+0xfb1/0x1f90 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2596
 do_vfs_ioctl+0xfbc/0x2f70 fs/ioctl.c:46
 ksys_ioctl fs/ioctl.c:713 [inline]
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:718
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:718
 do_syscall_64+0xcf/0x110 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7

Local variable description: ----e@nested_vmx_get_vmptr
Variable was created at:
 nested_vmx_get_vmptr+0xa5/0x3d0 arch/x86/kvm/vmx.c:8255
 handle_vmon+0x5ea/0xe70 arch/x86/kvm/vmx.c:8387
==================================================================

Crashes (29):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/11/20 14:26 https://github.com/google/kmsan.git master 2808e543aacb 9bc2a903 .config console log report syz C ci-upstream-kmsan-gce
2018/10/16 01:51 https://github.com/google/kmsan.git master 22ec98c3e38f 8cd30605 .config console log report syz ci-upstream-kmsan-gce
2019/03/05 17:21 https://github.com/google/kmsan.git master 6c55aa96dcda bb91cf81 .config console log report ci-upstream-kmsan-gce
2019/02/06 06:28 https://github.com/google/kmsan.git master fa1981bee40f d672172c .config console log report ci-upstream-kmsan-gce
2019/01/17 07:26 https://github.com/google/kmsan.git master 02f2d5aea531 c2faf9b2 .config console log report ci-upstream-kmsan-gce
2019/01/07 21:33 https://github.com/google/kmsan.git master 48128c3ca084 69d69aa9 .config console log report ci-upstream-kmsan-gce
2018/12/28 00:31 https://github.com/google/kmsan.git master 79fc24ff6184 af317504 .config console log report ci-upstream-kmsan-gce
2018/12/26 22:34 https://github.com/google/kmsan.git master 79fc24ff6184 e747ec98 .config console log report ci-upstream-kmsan-gce
2018/12/26 18:46 https://github.com/google/kmsan.git master 79fc24ff6184 8a41a0ad .config console log report ci-upstream-kmsan-gce
2018/12/24 22:38 https://github.com/google/kmsan.git master 79fc24ff6184 8a41a0ad .config console log report ci-upstream-kmsan-gce
2018/12/24 01:37 https://github.com/google/kmsan.git master 75b3ad224f19 e3bd7ab8 .config console log report ci-upstream-kmsan-gce
2018/12/19 15:26 https://github.com/google/kmsan.git master 49d30e29c6d8 fe2dc057 .config console log report ci-upstream-kmsan-gce
2018/12/19 14:07 https://github.com/google/kmsan.git master 49d30e29c6d8 fe2dc057 .config console log report ci-upstream-kmsan-gce
2018/12/19 14:04 https://github.com/google/kmsan.git master 49d30e29c6d8 fe2dc057 .config console log report ci-upstream-kmsan-gce
2018/12/15 06:47 https://github.com/google/kmsan.git master 0a602458c72c 7624ddd6 .config console log report ci-upstream-kmsan-gce
2018/11/30 01:37 https://github.com/google/kmsan.git master c1c8fce47960 66071e27 .config console log report ci-upstream-kmsan-gce
2018/11/29 04:18 https://github.com/google/kmsan.git master fffec98ae2a6 4b6d14f2 .config console log report ci-upstream-kmsan-gce
2018/11/26 02:27 https://github.com/google/kmsan.git master fffec98ae2a6 3d3ec907 .config console log report ci-upstream-kmsan-gce
2018/11/22 05:22 https://github.com/google/kmsan.git master 3ededcaa1606 9db828b5 .config console log report ci-upstream-kmsan-gce
2018/11/20 08:36 https://github.com/google/kmsan.git master 2808e543aacb 9bc2a903 .config console log report ci-upstream-kmsan-gce
2018/11/20 08:27 https://github.com/google/kmsan.git master 2808e543aacb 9bc2a903 .config console log report ci-upstream-kmsan-gce
2018/11/17 02:14 https://github.com/google/kmsan.git master cddc52641fd2 b08ee62a .config console log report ci-upstream-kmsan-gce
2018/11/14 17:14 https://github.com/google/kmsan.git master 006aa39cddee 5f5f6d14 .config console log report ci-upstream-kmsan-gce
2018/11/10 06:16 https://github.com/google/kmsan.git master 746f11553795 f9815aaf .config console log report ci-upstream-kmsan-gce
2018/11/10 06:13 https://github.com/google/kmsan.git master 746f11553795 f9815aaf .config console log report ci-upstream-kmsan-gce
2018/11/09 01:36 https://github.com/google/kmsan.git master 6fbdd09ed73e e85d2a61 .config console log report ci-upstream-kmsan-gce
2018/11/09 01:35 https://github.com/google/kmsan.git master 6fbdd09ed73e e85d2a61 .config console log report ci-upstream-kmsan-gce
2018/10/30 13:52 https://github.com/google/kmsan.git master cb4c1d77c7e1 8dbb755a .config console log report ci-upstream-kmsan-gce
2018/10/16 00:51 https://github.com/google/kmsan.git master 22ec98c3e38f 8cd30605 .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.