syzbot


WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr

Status: upstream: reported C repro on 2022/06/09 07:50
Reported-by: syzbot+e54f930ed78eb0f85281@syzkaller.appspotmail.com
Fix commit: af735db31285 KVM: x86/xen: Initialize Xen timer only once c03689913635 KVM: x86/xen: Stop Xen timer before changing IRQ
Patched on: [ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-arm64 ci-upstream-gce-leak ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce ci-upstream-kmsan-gce-386 ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu2-riscv64]
First crash: 111d, last: 55d

Cause bisection: introduced by (bisect log) :
commit 536395260582be7443b0b35b0bbb89ffe3947f62
Author: Joao Martins <joao.m.martins@oracle.com>
Date: Thu Mar 3 15:41:22 2022 +0000

  KVM: x86/xen: handle PV timers oneshot mode

Crash: WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr (log)
Repro: C syz .config
Patch testing requests:
Created Duration User Patch Repo Result
2022/07/28 17:54 15m dietschc@csp.edu patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master OK log
2022/07/28 17:46 0m dietschc@csp.edu patch https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master error

Sample crash report:
------------[ cut here ]------------
ODEBUG: init active (active state 0) object type: hrtimer hint: xen_timer_callback+0x0/0xb0 arch/x86/kvm/xen.c:1086
WARNING: CPU: 0 PID: 3615 at lib/debugobjects.c:502 debug_print_object+0x16e/0x250 lib/debugobjects.c:502
Modules linked in:
CPU: 0 PID: 3615 Comm: syz-executor343 Not tainted 5.19.0-rc7-syzkaller-00190-g70664fc10c0d #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/29/2022
RIP: 0010:debug_print_object+0x16e/0x250 lib/debugobjects.c:502
Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 af 00 00 00 48 8b 14 dd 40 79 28 8a 4c 89 ee 48 c7 c7 20 6d 28 8a e8 7c 1e 32 05 <0f> 0b 83 05 b5 62 bb 09 01 48 83 c4 18 5b 5d 41 5c 41 5d 41 5e c3
RSP: 0018:ffffc9000306f778 EFLAGS: 00010282
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: ffff88801d968000 RSI: ffffffff8160d1a8 RDI: fffff5200060dee1
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000000 R11: 0000000000000001 R12: ffffffff89cee540
R13: ffffffff8a2872a0 R14: ffffffff816a72e0 R15: ffffffff9114ced8
FS:  0000555555da53c0(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000021000000 CR3: 000000001f980000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 __debug_object_init+0x524/0xd10 lib/debugobjects.c:590
 debug_hrtimer_init kernel/time/hrtimer.c:414 [inline]
 debug_init kernel/time/hrtimer.c:468 [inline]
 hrtimer_init+0x23/0x2b0 kernel/time/hrtimer.c:1592
 kvm_xen_init_timer arch/x86/kvm/xen.c:168 [inline]
 kvm_xen_vcpu_set_attr+0x1ca/0x16c0 arch/x86/kvm/xen.c:716
 kvm_arch_vcpu_ioctl+0x1bb3/0x39d0 arch/x86/kvm/x86.c:5715
 kvm_vcpu_ioctl+0x973/0xf30 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4104
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:870 [inline]
 __se_sys_ioctl fs/ioctl.c:856 [inline]
 __x64_sys_ioctl+0x193/0x200 fs/ioctl.c:856
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f859bb34cd9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 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 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffd7a0db668 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007ffd7a0db678 RCX: 00007f859bb34cd9
RDX: 0000000020003680 RSI: 000000004048aecb RDI: 000000000000000b
RBP: 00007ffd7a0db670 R08: 00007f859baf7b00 R09: 00007f859baf7b00
R10: 00007f859baf7b00 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce 2022/07/23 22:04 upstream 70664fc10c0d 22343af4 .config log report syz C WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr
ci-upstream-kasan-gce 2022/07/31 19:31 upstream 6a010258447d fef302b1 .config log report info WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr
ci-upstream-kasan-gce 2022/07/23 21:29 upstream 70664fc10c0d 22343af4 .config log report info WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr
ci-upstream-kasan-gce 2022/06/04 23:09 upstream 032dcf09e2bf c8857892 .config log report info WARNING: ODEBUG bug in kvm_xen_vcpu_set_attr
* Struck through repros no longer work on HEAD.