INFO: rcu detected stall in kvm_vm_release (4)

Status: upstream: reported on 2026/08/20 13:16
Subsystems: mm
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+5f0b6e2e4195c75b5658@syzkaller.appspotmail.com
First crash: 650d, last: 7d02h
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
bc857902 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ✅ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ✅ VMHostTrigger: ❌ INFO: rcu detected stall in kvm_vm_release (4) 2026/05/25 01:21 2026/05/25 01:21 2026/05/25 02:19 c69befb3
Discussions (1)
Title Replies (including bot) Last reply
[syzbot] [mm?] INFO: rcu detected stall in kvm_vm_release (4) 3 (4) 2026/08/21 01:20
Similar bugs (5)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in kvm_vm_release (2) fs 1 1 1057d 1057d 0/29 auto-obsoleted due to no activity on 2024/01/02 09:35
linux-6.1 INFO: rcu detected stall in kvm_vm_release 1 1 190d 190d 0/3 auto-obsoleted due to no activity on 2026/05/29 08:31
upstream INFO: rcu detected stall in kvm_vm_release kernel 1 1 2292d 2292d 0/29 auto-closed as invalid on 2020/08/15 10:19
upstream INFO: rcu detected stall in kvm_vm_release (3) bpf net 1 1 816d 816d 0/29 auto-obsoleted due to no activity on 2024/08/30 21:11
android-6-12 BUG: soft lockup in kvm_vm_release 1 2 324d 328d 0/1 auto-obsoleted due to no activity on 2026/01/04 18:02

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P21500/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=207513, q=1145 ncpus=2)
task:syz.9.4605      state:R  running task     stack:26920 pid:21500 tgid:21500 ppid:14397  task_flags:0x40044c flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x17d4/0x5630 kernel/sched/core.c:7239
 preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7561
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x222/0x350 kernel/locking/lockdep.c:5890
Code: ff ff ff e8 c0 0b 32 0a f7 44 24 08 00 02 00 00 0f 84 39 ff ff ff 65 48 8b 05 12 77 cb 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 57 a1 b8
RSP: 0018:ffffc900074cf260 EFLAGS: 00000286
RAX: 7db047bb98fc4c00 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000c0065176 RSI: ffffffff8e4b5735 RDI: ffffffff8c4bdd80
RBP: ffffffff8177710f R08: ffffffff8177710f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb5a0e0 R12: 0000000000000002
R13: ffffffff8eb5a0e0 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:840 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
 unwind_next_frame+0xac/0x2550 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
 save_stack+0x122/0x230 mm/page_owner.c:165
 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0xc22/0xd20 mm/page_alloc.c:2950
 __slab_free+0x274/0x2c0 mm/slub.c:5741
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4584 [inline]
 slab_alloc_node mm/slub.c:4917 [inline]
 __do_kmalloc_node mm/slub.c:5333 [inline]
 __kmalloc_noprof+0x315/0x720 mm/slub.c:5359
 _kmalloc_noprof include/linux/slab.h:992 [inline]
 _kzalloc_noprof include/linux/slab.h:1309 [inline]
 kobject_get_path+0xc5/0x2f0 lib/kobject.c:161
 kobject_uevent_env+0x29e/0x9e0 lib/kobject_uevent.c:548
 kvm_uevent_notify_change+0x300/0x3a0 virt/kvm/kvm_main.c:6335
 kvm_destroy_vm virt/kvm/kvm_main.c:1260 [inline]
 kvm_put_kvm+0xa9/0xb50 virt/kvm/kvm_main.c:1331
 kvm_vm_release+0x43/0x50 virt/kvm/kvm_main.c:1354
 __fput+0x418/0xa50 fs/file_table.c:512
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0x73a/0x2360 kernel/exit.c:1009
 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
 get_signal+0x121b/0x12c0 kernel/signal.c:3046
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:336 [inline]
 do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe3a1f5e90e
RSP: 002b:00007fe3a2e23f58 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: fffffffffffffdfc RBX: 00007fe3a2e246c0 RCX: 00007fe3a1f5e90e
RDX: 00007fe3a2e23fb0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fe3a2035024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe3a2226308 R14: 00007fe3a2226270 R15: 00007fe3a234fa48
 </TASK>

Crashes (30):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/08/20 06:01 upstream e8bf40d15402 1e72964b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/08/16 20:01 upstream 3eb40771c00a 746171ee .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/08/01 10:00 upstream 0131b508c0e2 e611ffe1 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/07/19 02:42 upstream 1229e2e57a5c 72524a66 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/06/28 11:00 upstream 780d569e6c4b fb92f11c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/04/14 09:43 upstream 0f0013213293 1a086e7c .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/03/11 03:39 upstream b4f0dd314b39 86914af9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2026/02/16 00:48 upstream ca4ee40bf13d 1e62d198 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2025/12/14 08:23 upstream 4a298a43f5e3 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2025/10/21 18:24 upstream 6548d364a3e8 9832ed61 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2025/10/05 03:11 upstream d104e3d17f7b 49379ee0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2025/09/06 23:16 upstream d1d10cea0895 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2025/08/17 18:21 upstream 99bade344cfa 1804e95e .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2025/08/14 07:35 upstream 038d61fd6422 22ec1469 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kvm_vm_release
2025/07/22 14:29 upstream 89be9a83ccf1 1555463b .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2025/06/29 10:37 upstream dfba48a70cb6 fc9d8ee5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kvm_vm_release
2025/02/16 10:03 upstream 496659003dac 40a34ec9 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2024/12/08 07:48 upstream 7503345ac5f5 9ac0fdc6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vm_release
2024/12/04 21:53 upstream feffde684ac2 b50eb251 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2024/11/16 09:50 upstream f868cd251776 cfe3a04a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in kvm_vm_release
2024/11/14 11:05 upstream 0a9b9d17f3a7 a8c99394 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in kvm_vm_release
2026/01/29 18:43 upstream 8dfce8991b95 aeb6fdd5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in kvm_vm_release
2025/05/17 10:06 upstream 3c21441eeffc f41472b0 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-386 INFO: rcu detected stall in kvm_vm_release
2026/02/21 01:58 linux-next d4906ae14a5f 741f5161 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in kvm_vm_release
2025/12/06 05:31 linux-next 6987d58a9cbc d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kvm_vm_release
2025/11/29 03:41 linux-next 7d31f578f323 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kvm_vm_release
2025/09/24 09:58 linux-next ce7f1a983b07 0abd0691 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in kvm_vm_release
2025/09/15 19:46 linux-next 590b221ed425 e2beed91 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kvm_vm_release
2025/08/26 09:28 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in kvm_vm_release
2025/08/26 01:24 linux-next 7fa4d8dc380f bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-rust-kasan-gce INFO: rcu detected stall in kvm_vm_release
* Struck through repros no longer work on HEAD.