syzbot


WARNING in handle_desc

Status: fixed on 2019/10/15 23:40
Subsystems: kvm
[Documentation on labels]
Reported-by: syzbot+0f1819555fbdce992df9@syzkaller.appspotmail.com
Fix commit: 3ca94192278c KVM: X86: Fix userspace set invalid CR4
First crash: 1740d, last: 1730d
Cause bisection: introduced by (bisect log) :
commit 0367f205a3b7c0efe774634eef1f4697c79a4132
Author: Paolo Bonzini <pbonzini@redhat.com>
Date: Tue Jul 12 08:44:55 2016 +0000

  KVM: vmx: add support for emulating UMIP

Crash: WARNING in handle_desc (log)
Repro: C syz .config
  
Discussions (7)
Title Replies (including bot) Last reply
[PATCH 5.3 000/148] 5.3.6-stable review 163 (163) 2019/11/14 15:05
[PATCH 4.19 000/114] 4.19.79-stable review 124 (124) 2019/10/13 15:47
[PATCH v3] KVM: X86: Fix userspace set invalid CR4 3 (3) 2019/09/26 10:29
[PATCH 1/3] KVM: Fix coalesced mmio ring buffer out-of-bounds access 10 (10) 2019/09/24 13:55
Reminder: 4 active syzbot reports in kvm subsystem 1 (1) 2019/09/19 05:27
[PATCH] KVM: X86: Fix warning in handle_desc 3 (3) 2019/09/17 08:22
WARNING in handle_desc 0 (1) 2019/09/11 20:38
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream WARNING in handle_desc (2) kvm 1 1384d 1380d 0/27 auto-closed as invalid on 2020/12/29 08:10
linux-4.19 WARNING in handle_desc C done 1 1730d 1730d 1/1 fixed on 2019/12/09 13:28
linux-4.19 WARNING in handle_desc (2) C error 10 564d 1275d 0/1 upstream: reported C repro on 2020/12/18 04:57

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/hw-vuln/l1tf.html for details.
------------[ cut here ]------------
WARNING: CPU: 0 PID: 9878 at arch/x86/kvm/vmx/vmx.c:4678 handle_desc.cold+0x11/0x18 arch/x86/kvm/vmx/vmx.c:4678
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 9878 Comm: syz-executor390 Not tainted 5.3.0+ #0
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+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2dc/0x755 kernel/panic.c:219
 __warn.cold+0x20/0x4c kernel/panic.c:576
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:handle_desc.cold+0x11/0x18 arch/x86/kvm/vmx/vmx.c:4678
Code: 00 48 c7 c7 20 e7 83 87 c6 05 77 04 86 08 01 e8 f7 65 40 00 e9 a5 42 fd ff e8 e9 c6 56 00 48 c7 c7 80 e7 83 87 e8 e1 65 40 00 <0f> 0b e9 75 44 fd ff e8 d1 c6 56 00 89 de 48 c7 c7 e0 e7 83 87 c6
RSP: 0018:ffff88809336f9a0 EFLAGS: 00010282
RAX: 0000000000000024 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815c3826 RDI: ffffed101266df26
RBP: ffff88809336f9b0 R08: 0000000000000024 R09: ffffed1015d060d1
R10: ffffed1015d060d0 R11: ffff8880ae830687 R12: ffff8880958c8040
R13: 000000000000002f R14: ffff8880958cbc0c R15: ffff8880958c8070
 vmx_handle_exit+0x299/0x15e0 arch/x86/kvm/vmx/vmx.c:5886
 vcpu_enter_guest+0x1087/0x5e90 arch/x86/kvm/x86.c:8095
 vcpu_run arch/x86/kvm/x86.c:8159 [inline]
 kvm_arch_vcpu_ioctl_run+0x464/0x1750 arch/x86/kvm/x86.c:8367
 kvm_vcpu_ioctl+0x4dc/0xfd0 arch/x86/kvm/../../../virt/kvm/kvm_main.c:2765
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:696
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
 __do_sys_ioctl fs/ioctl.c:720 [inline]
 __se_sys_ioctl fs/ioctl.c:718 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x443819
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:00007ffe512f8218 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffe512f8220 RCX: 0000000000443819
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000006
RBP: 0000000000000000 R08: 00000000004010a0 R09: 00000000004010a0
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000004048c0
R13: 0000000000404950 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/17 05:49 upstream cef7298262e9 51ca0454 .config console log report syz C ci-upstream-kasan-gce-root
2019/09/16 02:15 upstream 1609d7604b84 32d59357 .config console log report syz C ci-upstream-kasan-gce-smack-root
2019/09/16 01:09 upstream 1609d7604b84 32d59357 .config console log report syz C ci-upstream-kasan-gce-selinux-root
2019/09/20 05:28 linux-next eb2f12732f67 4d3ae0b7 .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/09/10 15:00 linux-next 6d028043b55e a60cb4cd .config console log report syz C ci-upstream-linux-next-kasan-gce-root
2019/09/10 14:21 linux-next 6d028043b55e a60cb4cd .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.