syzbot


WARNING: locking bug in kvm_xen_set_evtchn_fast

Status: upstream: reported C repro on 2024/11/21 15:03
Subsystems: kvm-x86 kvm
[Documentation on labels]
Reported-by: syzbot+919877893c9d28162dc2@syzkaller.appspotmail.com
First crash: 202d, last: 4d06h
Cause bisection: introduced by (bisect log) :
commit 560af5dc839eef08a273908f390cfefefb82aa04
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Wed Oct 9 15:45:03 2024 +0000

  lockdep: Enable PROVE_RAW_LOCK_NESTING with PROVE_LOCKING.

Crash: WARNING: locking bug in kvm_xen_set_evtchn_fast (log)
Repro: C syz .config
  
Discussions (7)
Title Replies (including bot) Last reply
[syzbot] Monthly kvm-x86 report (Jun 2025) 0 (1) 2025/06/08 17:33
[syzbot] Monthly kvm report (May 2025) 0 (1) 2025/05/12 13:34
[syzbot] Monthly kvm report (Apr 2025) 0 (1) 2025/04/02 09:38
[syzbot] Monthly kvm report (Feb 2025) 0 (1) 2025/02/11 13:32
[syzbot] Monthly kvm report (Jan 2025) 0 (1) 2025/01/13 10:54
[syzbot] Monthly kvm report (Dec 2024) 0 (1) 2024/12/11 11:27
[syzbot] [kvm?] WARNING: locking bug in kvm_xen_set_evtchn_fast 4 (7) 2024/11/26 16:26

Sample crash report:
=============================
[ BUG: Invalid wait context ]
6.12.0-syzkaller-07834-g06afb0f36106 #0 Not tainted
-----------------------------
kworker/0:1/9 is trying to lock:
ffffc90003bca460 (&gpc->lock){....}-{3:3}, at: kvm_xen_set_evtchn_fast+0x1ee/0xa00 arch/x86/kvm/xen.c:1755
other info that might help us debug this:
context-{2:2}
6 locks held by kworker/0:1/9:
 #0: ffff888144a92148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3204 [inline]
 #0: ffff888144a92148 ((wq_completion)usb_hub_wq){+.+.}-{0:0}, at: process_scheduled_works+0x93b/0x1850 kernel/workqueue.c:3310
 #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3205 [inline]
 #1: ffffc900000e7d00 ((work_completion)(&hub->events)){+.+.}-{0:0}, at: process_scheduled_works+0x976/0x1850 kernel/workqueue.c:3310
 #2: ffff888145711190 (&dev->mutex){....}-{4:4}, at: device_lock include/linux/device.h:1014 [inline]
 #2: ffff888145711190 (&dev->mutex){....}-{4:4}, at: hub_event+0x1fe/0x5150 drivers/usb/core/hub.c:5849
 #3: ffffffff8e817de0 (console_lock){+.+.}-{0:0}, at: dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4942
 #4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: rcu_try_lock_acquire include/linux/rcupdate.h:342 [inline]
 #4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: srcu_read_lock_nmisafe include/linux/srcu.h:297 [inline]
 #4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: console_srcu_read_lock kernel/printk/printk.c:288 [inline]
 #4: ffffffff8e8179f0 (console_srcu){....}-{0:0}, at: console_flush_all+0x1a3/0xeb0 kernel/printk/printk.c:3187
 #5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_lock_acquire include/linux/srcu.h:158 [inline]
 #5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: srcu_read_lock include/linux/srcu.h:249 [inline]
 #5: ffffc90003bca8c8 (&kvm->srcu){.?.+}-{0:0}, at: kvm_xen_set_evtchn_fast+0x1bb/0xa00 arch/x86/kvm/xen.c:1753
stack backtrace:
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:1 Not tainted 6.12.0-syzkaller-07834-g06afb0f36106 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Workqueue: usb_hub_wq hub_event
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_lock_invalid_wait_context kernel/locking/lockdep.c:4826 [inline]
 check_wait_context kernel/locking/lockdep.c:4898 [inline]
 __lock_acquire+0x15a8/0x2100 kernel/locking/lockdep.c:5176
 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5849
 __raw_read_lock_irqsave include/linux/rwlock_api_smp.h:160 [inline]
 _raw_read_lock_irqsave+0xdd/0x130 kernel/locking/spinlock.c:236
 kvm_xen_set_evtchn_fast+0x1ee/0xa00 arch/x86/kvm/xen.c:1755
 xen_timer_callback+0x1a0/0x380 arch/x86/kvm/xen.c:140
 __run_hrtimer kernel/time/hrtimer.c:1739 [inline]
 __hrtimer_run_queues+0x551/0xd50 kernel/time/hrtimer.c:1803
 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
 __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:console_flush_all+0x996/0xeb0
Code: 48 21 c3 0f 85 16 02 00 00 e8 66 aa 20 00 4c 8b 7c 24 10 4d 85 f6 75 07 e8 57 aa 20 00 eb 06 e8 50 aa 20 00 fb 48 8b 5c 24 18 <48> 8b 44 24 30 42 80 3c 28 00 74 08 48 89 df e8 76 61 8b 00 4c 8b
RSP: 0018:ffffc900000e7000 EFLAGS: 00000293
RAX: ffffffff8174a2e0 RBX: ffffffff8f17fa58 RCX: ffff88801bef8000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000e71b0 R08: ffffffff8174a2b7 R09: 1ffffffff285cb10
R10: dffffc0000000000 R11: fffffbfff285cb11 R12: ffffffff8f17fa00
R13: dffffc0000000000 R14: 0000000000000200 R15: ffffc900000e7200
 __console_flush_and_unlock kernel/printk/printk.c:3269 [inline]
 console_unlock+0x14f/0x3b0 kernel/printk/printk.c:3309
 vprintk_emit+0x730/0xa10 kernel/printk/printk.c:2432
 dev_vprintk_emit+0x2ae/0x330 drivers/base/core.c:4942
 dev_printk_emit+0xdd/0x120 drivers/base/core.c:4953
 _dev_info+0x122/0x170 drivers/base/core.c:5011
 show_string drivers/usb/core/hub.c:2357 [inline]
 announce_device drivers/usb/core/hub.c:2375 [inline]
 usb_new_device+0xd02/0x19a0 drivers/usb/core/hub.c:2632
 hub_port_connect drivers/usb/core/hub.c:5521 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5661 [inline]
 port_event drivers/usb/core/hub.c:5821 [inline]
 hub_event+0x2d6d/0x5150 drivers/usb/core/hub.c:5903
 process_one_work kernel/workqueue.c:3229 [inline]
 process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310
 worker_thread+0x870/0xd30 kernel/workqueue.c:3391
 kthread+0x2f0/0x390 kernel/kthread.c:389
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
----------------
Code disassembly (best guess):
   0:	48 21 c3             	and    %rax,%rbx
   3:	0f 85 16 02 00 00    	jne    0x21f
   9:	e8 66 aa 20 00       	call   0x20aa74
   e:	4c 8b 7c 24 10       	mov    0x10(%rsp),%r15
  13:	4d 85 f6             	test   %r14,%r14
  16:	75 07                	jne    0x1f
  18:	e8 57 aa 20 00       	call   0x20aa74
  1d:	eb 06                	jmp    0x25
  1f:	e8 50 aa 20 00       	call   0x20aa74
  24:	fb                   	sti
  25:	48 8b 5c 24 18       	mov    0x18(%rsp),%rbx
* 2a:	48 8b 44 24 30       	mov    0x30(%rsp),%rax <-- trapping instruction
  2f:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  34:	74 08                	je     0x3e
  36:	48 89 df             	mov    %rbx,%rdi
  39:	e8 76 61 8b 00       	call   0x8b61b4
  3e:	4c                   	rex.WR
  3f:	8b                   	.byte 0x8b

Crashes (585):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/23 13:17 upstream 06afb0f36106 68da6d95 .config strace log report syz / log C [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/03/04 11:39 upstream 99fa936e8e4f c3901742 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 08:27 upstream e0797d3b91de 3d2f584d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/14 22:44 upstream 9f35e33144ae a4fa04ef .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/14 09:15 upstream 405e6c37c89e 7344edeb .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/02/25 03:20 upstream d082ecbc71e9 d34966d1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/05 03:19 upstream 1af80d00e1e0 fd5e6e61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/04 01:51 upstream 546b1c9e93c2 a30356b7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/28 09:28 upstream 015a99fa7665 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/26 18:43 upstream 0ff41df1cb26 874a1386 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/18 11:38 upstream 5723cc3450bc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/13 00:56 upstream 627277ba7c23 f6671af7 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/12 15:49 upstream 82f2b0b97b36 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/12 08:05 upstream 82f2b0b97b36 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/12 06:36 upstream 82f2b0b97b36 77908e5f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/09 16:07 upstream 9c69f8884904 bb813bcc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/07 13:21 upstream 0d8d44db295c 350f4ffc .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/07 04:14 upstream c0c9379f235d 4826c28e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/07 02:19 upstream c0c9379f235d 4826c28e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/05 21:03 upstream ec7714e49479 6b6b5f21 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/04 00:27 upstream 5abc7438f1e9 a30356b7 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/06/01 22:35 upstream 7d4e49a77d99 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/31 22:55 upstream 0f70f5b08a47 3d2f584d .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/31 09:46 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/31 08:05 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/31 04:48 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/31 02:05 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 21:50 upstream 8477ab143069 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 20:31 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 17:45 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 16:22 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 14:56 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 13:51 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 12:45 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 11:43 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 10:41 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 09:36 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 08:29 upstream f66bc387efbe 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 06:36 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 05:25 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 03:53 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 02:53 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/30 00:50 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/29 22:49 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/29 21:42 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/29 21:41 upstream e0797d3b91de 3d2f584d .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/26 20:18 upstream 0ff41df1cb26 06877188 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/24 16:42 upstream 4856ebd99715 ed351ea7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/21 01:53 upstream b36ddb9210e6 b47f9e02 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/17 11:56 upstream 172a9d94339c f41472b0 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/04 23:11 upstream e8ab83e34bdc b0714e37 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/05/04 21:32 upstream e8ab83e34bdc b0714e37 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root WARNING: locking bug in kvm_xen_set_evtchn_fast
2024/11/21 10:38 upstream 8f7c8b88bda4 4b25d554 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2024/11/21 04:53 upstream 8f7c8b88bda4 4b25d554 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream WARNING: locking bug in kvm_xen_set_evtchn_fast
2025/04/12 23:05 upstream 3bde70a2c827 0bd6db41 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 WARNING: locking bug in kvm_xen_set_evtchn_fast
* Struck through repros no longer work on HEAD.