syzbot


INFO: rcu detected stall in __run_timers (2)

Status: upstream: reported on 2025/09/03 11:07
Reported-by: syzbot+cd14d7355b2f09d8aa58@syzkaller.appspotmail.com
First crash: 255d, last: 2d18h
Similar bugs (15)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in __run_timers (4) tomoyo 1 4 2292d 2306d 0/29 auto-closed as invalid on 2020/05/06 02:55
linux-5.15 INFO: rcu detected stall in __run_timers 1 1 1125d 1125d 0/3 auto-obsoleted due to no activity on 2023/08/15 19:18
upstream INFO: rcu detected stall in __run_timers net 1 2 2806d 2808d 0/29 closed as invalid on 2018/09/11 10:51
upstream INFO: rcu detected stall in __run_timers (2) block 1 58 2679d 2802d 0/29 closed as dup on 2019/01/02 16:40
linux-6.1 INFO: rcu detected stall in __run_timers (2) origin:upstream 1 syz error 1 216d 216d 0/3 upstream: reported syz repro on 2025/10/12 10:55
upstream INFO: rcu detected stall in __run_timers (7) kernfs 1 25 614d 719d 0/29 auto-obsoleted due to no activity on 2024/11/08 17:44
linux-6.1 INFO: rcu detected stall in __run_timers 1 1 573d 573d 0/3 auto-obsoleted due to no activity on 2025/01/28 16:20
upstream INFO: rcu detected stall in __run_timers (6) kernel 1 2 1534d 1550d 0/29 auto-closed as invalid on 2022/06/02 21:46
upstream INFO: rcu detected stall in __run_timers (3) mm 1 4 2418d 2440d 0/29 auto-closed as invalid on 2019/12/31 08:04
upstream INFO: rcu detected stall in __run_timers (5) kernel 1 C error error 63 1566d 2079d 0/29 closed as invalid on 2022/02/08 10:39
android-5-10 BUG: soft lockup in __run_timers 1 2 635d 703d 0/2 auto-obsoleted due to no activity on 2024/11/18 04:44
android-54 BUG: soft lockup in __run_timers 1 1 688d 688d 0/2 auto-obsoleted due to no activity on 2024/09/26 00:22
android-5-15 BUG: soft lockup in __run_timers 1 1 606d 606d 0/2 auto-obsoleted due to no activity on 2024/12/16 23:50
upstream BUG: soft lockup in __run_timers kernel 1 1 1196d 1192d 0/29 auto-obsoleted due to no activity on 2023/05/06 12:08
android-54 BUG: soft lockup in __run_timers (2) 1 2 407d 470d 0/2 auto-obsoleted due to no activity on 2025/07/03 11:27

Sample crash report:
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-....: (10499 ticks this GP) idle=473/1/0x4000000000000000 softirq=51251/51251 fqs=5248 
	(t=10501 jiffies g=76537 q=1660)
NMI backtrace for cpu 0
CPU: 0 PID: 16214 Comm: syz.0.2605 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ea/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 be 59 97 f7 48 89 df e8 f6 31 98 f7 e8 01 27 b9 f7 fb bf 01 00 00 00 <e8> d6 38 8c f7 65 8b 05 67 36 3c 76 85 c0 74 02 5b c3 e8 b4 43 3a
RSP: 0018:ffffc90000007c90 EFLAGS: 00000286
RAX: 7424da610a4fbf00 RBX: ffff8880b90280c0 RCX: 7424da610a4fbf00
RDX: dffffc0000000000 RSI: ffffffff8a2b2800 RDI: 0000000000000001
RBP: ffffc90000007df0 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: ffff8880b90280c0
R13: 1ffff11017205020 R14: ffffffff96650520 R15: ffffc90000007d40
 expire_timers kernel/time/timer.c:1698 [inline]
 __run_timers+0x52f/0x800 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x339/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
 sysvec_irq_work+0x9d/0xc0 arch/x86/kernel/irq_work.c:17
 </IRQ>
 <TASK>
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:preempt_schedule_irq+0xb6/0x160 kernel/sched/core.c:6799
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 7f bf 01 00 00 00 e8 b5 5d 8d f7 e8 60 4d ba f7 fb bf 01 00 00 00 <e8> 65 b5 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc90003a0f840 EFLAGS: 00000286
RAX: 7424da610a4fbf00 RBX: 0000000000000000 RCX: 7424da610a4fbf00
RDX: dffffc0000000000 RSI: ffffffff8a2b2800 RDI: 0000000000000001
RBP: ffffc90003a0f8f0 R08: ffff8880b903b30b R09: 1ffff11017207661
R10: dffffc0000000000 R11: ffffed1017207662 R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000741f08
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:209
Code: 8b 15 25 3b 89 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 <48> 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39
RSP: 0018:ffffc90003a0f9b8 EFLAGS: 00000246
RAX: ffffffff81c27a0d RBX: ffffc90003a0fa60 RCX: ffff88802c5b3b80
RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff888074620200
RBP: ffffc90003a0fad8 R08: ffff88814077c197 R09: 1ffff110280ef832
R10: dffffc0000000000 R11: ffffed10280ef833 R12: ffff888074620200
R13: dffffc0000000000 R14: 0000000000406dc2 R15: 0000000000000001
 page_counter_try_charge+0x1d/0x2c0 mm/page_counter.c:101
 obj_cgroup_charge_pages+0x136/0x1a0 mm/memcontrol.c:3023
 __memcg_kmem_charge_page+0x2fe/0x380 mm/memcontrol.c:3058
 __alloc_pages+0x225/0x480 mm/page_alloc.c:5518
 vm_area_alloc_pages mm/vmalloc.c:2876 [inline]
 __vmalloc_area_node mm/vmalloc.c:2932 [inline]
 __vmalloc_node_range+0x4b2/0x8b0 mm/vmalloc.c:3037
 __bpf_map_area_alloc kernel/bpf/syscall.c:328 [inline]
 bpf_map_area_alloc+0xd4/0xe0 kernel/bpf/syscall.c:335
 array_map_alloc+0x27c/0x6f0 kernel/bpf/arraymap.c:142
 find_and_alloc_map kernel/bpf/syscall.c:129 [inline]
 map_create+0x485/0x2350 kernel/bpf/syscall.c:881
 __sys_bpf+0x30a/0x6f0 kernel/bpf/syscall.c:4639
 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fdb75899e59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fdb73ab1028 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007fdb75b13180 RCX: 00007fdb75899e59
RDX: 0000000000000050 RSI: 00002000000004c0 RDI: 0000000000000000
RBP: 00007fdb7592fd6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fdb75b13218 R14: 00007fdb75b13180 R15: 00007fff1e7dcb38
 </TASK>

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/05/14 13:19 linux-5.15.y de8dfb3f0278 6ccb967e .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/04/27 17:20 linux-5.15.y b9d57c40a767 0f700595 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/04/26 08:42 linux-5.15.y b9d57c40a767 9c2d0995 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2026/01/24 21:23 linux-5.15.y 9eec9a14ee10 40acda8a .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/12/01 14:20 linux-5.15.y cc5ec8769306 d6526ea3 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/10/11 12:15 linux-5.15.y 29e53a5b1c4f ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
2025/09/03 11:07 linux-5.15.y 01879f56bdde 96a211bc .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan-perf INFO: rcu detected stall in __run_timers
* Struck through repros no longer work on HEAD.