INFO: rcu detected stall in kvm_vcpu_release (3)

Status: auto-obsoleted due to no activity on 2026/07/19 08:55
Subsystems: mm
Labels: prio:high
[Documentation on labels]
First crash: 114d, last: 114d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
3c4c2f5a assessment-security DenialOfService: ❌ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ✅ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in kvm_vcpu_release (3) 2026/05/26 02:22 2026/05/26 02:22 2026/05/26 03:21 c69befb3
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in kvm_vcpu_release kernel 1 1 2664d 2664d 0/29 auto-closed as invalid on 2019/10/24 01:16
upstream INFO: rcu detected stall in kvm_vcpu_release (2) fs 1 1 796d 796d 0/29 auto-obsoleted due to no activity on 2024/09/05 03:45
linux-5.15 INFO: rcu detected stall in kvm_vcpu_release 1 1 809d 809d 0/3 auto-obsoleted due to no activity on 2024/09/02 00:50

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7195/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=26773, q=1512 ncpus=2)
task:syz.2.344       state:R  running task     stack:25000 pid:7195  tgid:7193  ppid:5858   task_flags:0x400040 flags:0x00080003
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7188
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x730 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0xd/0x3c0 kernel/locking/lockdep.c:5876
Code: 00 00 00 e9 0e ff ff ff 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 41 57 41 56 41 55 41 54 <53> 48 83 ec 30 49 89 f5 49 89 fe 65 48 8b 05 a0 33 9e 11 48 89 44
RSP: 0018:ffffc9001ba574a8 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 00007fbeb0632c01 RCX: 0000000080000001
RDX: ffffffff90bf5b00 RSI: ffffffff81770256 RDI: ffffffff8e95cce0
RBP: dffffc0000000000 R08: 0000000000000022 R09: ffffffff8e95cce0
R10: ffffc9001ba575f8 R11: ffffffff81b0f560 R12: 00007fbeb13f1028
R13: ffffc9001ba50000 R14: ffffc9001ba575a8 R15: ffffffff81770256
 rcu_lock_release include/linux/rcupdate.h:310 [inline]
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0x1bba/0x2550 arch/x86/kernel/unwind_orc.c:709
 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:1402 [inline]
 __free_frozen_pages+0xbc7/0xd30 mm/page_alloc.c:2943
 kvm_mmu_free_memory_cache+0x11a/0x240 virt/kvm/kvm_main.c:419
 mmu_free_memory_caches arch/x86/kvm/mmu/mmu.c:626 [inline]
 kvm_mmu_destroy+0x336/0x390 arch/x86/kvm/mmu/mmu.c:7643
 kvm_arch_vcpu_destroy+0x28e/0x380 arch/x86/kvm/x86.c:12969
 kvm_vcpu_destroy virt/kvm/kvm_main.c:468 [inline]
 kvm_destroy_vcpus+0x123/0x380 virt/kvm/kvm_main.c:488
 kvm_arch_destroy_vm+0xf9/0x2d0 arch/x86/kvm/x86.c:13517
 kvm_destroy_vm virt/kvm/kvm_main.c:1294 [inline]
 kvm_put_kvm+0x6ca/0xa50 virt/kvm/kvm_main.c:1331
 kvm_vcpu_release+0x54/0x60 virt/kvm/kvm_main.c:4094
 __fput+0x44f/0xa60 fs/file_table.c:510
 task_work_run+0x1d9/0x270 kernel/task_work.c:233
 get_signal+0x11eb/0x1330 kernel/signal.c:2809
 arch_do_signal_or_restart+0xbc/0x830 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
 exit_to_user_mode_loop+0x86/0x480 kernel/entry/common.c:98
 __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:238 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:328 [inline]
 do_syscall_64+0x33e/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fbeb059c819
RSP: 002b:00007fbeb13f1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 00007fbeb0816090 RCX: 00007fbeb059c819
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000009
RBP: 00007fbeb0632c91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbeb0816128 R14: 00007fbeb0816090 R15: 00007fbeb093fa48
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/20 08:47 upstream c1f49dea2b8f 303e2802 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce INFO: rcu detected stall in kvm_vcpu_release
* Struck through repros no longer work on HEAD.