INFO: rcu detected stall in delayed_vfree_work (2)

Status: auto-obsoleted due to no activity on 2026/10/08 19:20
Subsystems: kernel
Labels: prio:normal
[Documentation on labels]
First crash: 95d, last: 95d
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ID Workflow Result Correct Bug Created Started Finished Revision
2d405b5d assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ INFO: rcu detected stall in delayed_vfree_work (2) 2026/07/12 00:54 2026/07/12 00:54 2026/07/12 01:26 d78ea535
▶ ▼ Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in delayed_vfree_work mm 1 1 429d 429d 0/29 auto-obsoleted due to no activity on 2025/11/08 17:34

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=c56c/1/0x4000000000000000 softirq=143018/143024 fqs=1
rcu: 	(detected by 1, t=10503 jiffies, g=166953, q=463 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Workqueue: events delayed_vfree_work
RIP: 0010:arch_atomic_try_cmpxchg arch/x86/include/asm/atomic.h:107 [inline]
RIP: 0010:raw_atomic_try_cmpxchg_acquire include/linux/atomic/atomic-arch-fallback.h:2170 [inline]
RIP: 0010:atomic_try_cmpxchg_acquire include/linux/atomic/atomic-instrumented.h:1302 [inline]
RIP: 0010:queued_spin_lock include/asm-generic/qspinlock.h:111 [inline]
RIP: 0010:do_raw_spin_lock+0x139/0x260 kernel/locking/spinlock_debug.c:116
Code: 28 00 00 00 00 e8 a7 9c 94 00 be 04 00 00 00 48 8d 7c 24 28 e8 98 9c 94 00 8b 44 24 28 ba 01 00 00 00 89 44 24 04 f0 0f b1 13 <0f> 85 93 00 00 00 48 89 ea 65 44 8b 35 2a 9d 7d 12 48 b8 00 00 00
RSP: 0000:ffffc90000007d50 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff8880237ca2a8 RCX: ffffffff81e5b2e8
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000007d78
RBP: ffff8880237ca2b0 R08: 0000000000000001 R09: fffff52000000faf
R10: 0000000000000003 R11: 0000000000000000 R12: 1ffff92000000fab
R13: ffff8880237ca2b8 R14: ffff8880b8428640 R15: ffff8880b8428690
FS:  0000000000000000(0000) GS:ffff888123deb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a0e7ddf74 CR3: 0000000038c8d000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000086
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 spin_lock include/linux/spinlock.h:342 [inline]
 advance_sched+0xe5/0xd20 net/sched/sch_taprio.c:930
 __run_hrtimer kernel/time/hrtimer.c:2032 [inline]
 __hrtimer_run_queues+0x462/0x9c0 kernel/time/hrtimer.c:2096
 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
 __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
 sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x31/0x80 kernel/locking/spinlock.c:198
Code: f5 53 48 8b 74 24 10 48 89 fb 48 83 c7 18 e8 16 5f 29 f6 48 89 df e8 9e ae 29 f6 f7 c5 00 02 00 00 75 23 9c 58 f6 c4 02 75 37 <bf> 01 00 00 00 e8 a5 bf 18 f6 65 8b 05 ee 48 a7 08 85 c0 74 16 5b
RSP: 0000:ffffc900000e78e8 EFLAGS: 00000246
RAX: 0000000000000002 RBX: ffffffff9b968648 RCX: 0000000000000040
RDX: 0000000000000000 RSI: ffffffff8e1a312a RDI: ffffffff8c400c80
RBP: 0000000000000282 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: 0000000000000002 R14: 0000000000000002 R15: ffff88807b854000
 __debug_check_no_obj_freed lib/debugobjects.c:1180 [inline]
 debug_check_no_obj_freed+0x31f/0x630 lib/debugobjects.c:1201
 __free_pages_prepare mm/page_alloc.c:1413 [inline]
 free_pages_prepare+0x3a7/0xd80 mm/page_alloc.c:1451
 __free_contig_range_common+0x14f/0x250 mm/page_alloc.c:6897
 __free_contig_range mm/page_alloc.c:6942 [inline]
 free_pages_bulk+0x12a/0x200 mm/page_alloc.c:5257
 vm_area_free_pages+0xad/0x2b0 mm/vmalloc.c:3439
 vfree mm/vmalloc.c:3488 [inline]
 vfree+0x107/0x750 mm/vmalloc.c:3462
 delayed_vfree_work+0x56/0x80 mm/vmalloc.c:3392
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 10495 jiffies! g166953 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:27592 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5510 [inline]
 __schedule+0x125c/0x6730 kernel/sched/core.c:7234
 __schedule_loop kernel/sched/core.c:7311 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7326
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 17401 Comm: kworker/u8:44 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x58e/0x16c0 kernel/smp.c:892
Code: 00 fc ff df 48 8b 54 24 08 49 89 d5 49 89 d4 49 c1 ed 03 41 83 e4 07 49 01 c5 41 83 c4 03 e8 a9 95 0c 00 f3 90 41 0f b6 45 00 <41> 38 c4 7c 08 84 c0 0f 85 2c 0f 00 00 8b 45 08 31 ff 83 e0 01 41
RSP: 0018:ffffc900054b7878 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff81fd3abd
RDX: ffff888036b62540 RSI: ffffffff81fd3a97 RDI: ffff888036b62540
RBP: ffff8880b8443680 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170886d1 R14: 0000000000000001 R15: ffff8880b853c880
FS:  0000000000000000(0000) GS:ffff888123eeb000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3a11831679 CR3: 000000000e992000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
 on_each_cpu include/linux/smp.h:72 [inline]
 smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
 smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x37a/0x550 kernel/jump_label.c:910
 static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
 static_key_enable+0x1a/0x20 kernel/jump_label.c:223
 toggle_allocation_gate mm/kfence/core.c:911 [inline]
 toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:903
 process_one_work+0xa23/0x1940 kernel/workqueue.c:3322
 process_scheduled_works kernel/workqueue.c:3405 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3486
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/07/10 19:10 upstream a635d6748234 99e64375 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in delayed_vfree_work
* Struck through repros no longer work on HEAD.