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KMSAN: uninit-value in __vmx_flush_tlb

Status: closed as invalid on 2018/10/08 08:59
Subsystems: kvm
[Documentation on labels]
First crash: 2030d, last: 2026d

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.
IPv6: ADDRCONF(NETDEV_UP): veth1: link is not ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth1: link becomes ready
IPv6: ADDRCONF(NETDEV_CHANGE): veth0: link becomes ready
==================================================================
BUG: KMSAN: uninit-value in __invept arch/x86/kvm/vmx.c:2098 [inline]
BUG: KMSAN: uninit-value in ept_sync_context arch/x86/kvm/vmx.c:2266 [inline]
BUG: KMSAN: uninit-value in __vmx_flush_tlb+0x755/0x790 arch/x86/kvm/vmx.c:5129
CPU: 1 PID: 6809 Comm: syz-executor0 Not tainted 4.19.0-rc4+ #63
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+0x306/0x460 lib/dump_stack.c:113
 kmsan_report+0x1a3/0x2d0 mm/kmsan/kmsan.c:917
 __msan_warning+0x7c/0xe0 mm/kmsan/kmsan_instr.c:500
 __invept arch/x86/kvm/vmx.c:2098 [inline]
 ept_sync_context arch/x86/kvm/vmx.c:2266 [inline]
 __vmx_flush_tlb+0x755/0x790 arch/x86/kvm/vmx.c:5129
 vmx_flush_tlb+0x94/0xb0 arch/x86/kvm/vmx.c:5137
 kvm_mmu_load+0x1656/0x3460 arch/x86/kvm/mmu.c:4960
 kvm_mmu_reload arch/x86/kvm/mmu.h:86 [inline]
 vcpu_enter_guest arch/x86/kvm/x86.c:7513 [inline]
 vcpu_run arch/x86/kvm/x86.c:7711 [inline]
 kvm_arch_vcpu_ioctl_run+0x879e/0x10a20 arch/x86/kvm/x86.c:7888
 kvm_vcpu_ioctl+0x11a7/0x20b0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2590
 vfs_ioctl fs/ioctl.c:46 [inline]
 do_vfs_ioctl+0xcf3/0x2810 fs/ioctl.c:687
 ksys_ioctl fs/ioctl.c:702 [inline]
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl+0x1da/0x270 fs/ioctl.c:707
 __x64_sys_ioctl+0x4a/0x70 fs/ioctl.c:707
 do_syscall_64+0xbe/0x100 arch/x86/entry/common.c:291
 entry_SYSCALL_64_after_hwframe+0x63/0xe7
RIP: 0033:0x457579
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f057836ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f057836f6d4
R13: 00000000004c003b R14: 00000000004d0108 R15: 00000000ffffffff

Local variable description: ----error.i.i.i@__vmx_flush_tlb
Variable was created at:
 __vmx_flush_tlb+0x103/0x790 arch/x86/kvm/vmx.c:5125
 vmx_flush_tlb+0x94/0xb0 arch/x86/kvm/vmx.c:5137
==================================================================

Crashes (20):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/10/07 15:25 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/07 15:19 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/07 05:53 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/06 18:41 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/06 02:35 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 23:16 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 16:53 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 16:17 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 10:11 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 07:31 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 06:44 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/05 04:40 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/04 22:23 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/04 18:02 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/04 17:42 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/04 11:49 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/04 05:25 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/03 22:27 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/03 18:46 https://github.com/google/kmsan.git master b2efdb2ef006 8b311eaf .config console log report ci-upstream-kmsan-gce
2018/10/03 11:35 https://github.com/google/kmsan.git master b2efdb2ef006 0f3e0261 .config console log report ci-upstream-kmsan-gce
* Struck through repros no longer work on HEAD.