INFO: rcu detected stall in sys_futex (5)

Status: auto-obsoleted due to no activity on 2023/02/12 18:33
Subsystems: kernel
[Documentation on labels]
First crash: 1625d, last: 1380d
▶ ▼ Similar bugs (11)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in futex (2) origin:lts-only 1 syz, C inconclusive 70 7d21h 277d 0/2 upstream: reported C repro on 2025/10/31 01:02
upstream INFO: rcu detected stall in sys_futex (7) prio:high kernel 1 syz error error 139 12h18m 771d 0/29 upstream: reported syz repro on 2024/06/24 16:48
upstream INFO: rcu detected stall in sys_futex (3) mm 1 959 2400d 2449d 0/29 auto-closed as invalid on 2020/03/08 12:44
upstream INFO: rcu detected stall in sys_futex (2) kernel 1 6 2568d 2712d 0/29 auto-closed as invalid on 2019/10/25 14:11
upstream INFO: rcu detected stall in sys_futex (4) kernel 1 1 1649d 1649d 0/29 closed as invalid on 2022/02/08 10:00
linux-5.15 INFO: rcu detected stall in sys_futex (2) origin:lts-only 1 syz, C error 95 2d03h 790d 0/3 upstream: reported C repro on 2024/06/05 16:49
upstream INFO: rcu detected stall in sys_futex kernel 1 1 2773d 2773d 0/29 closed as invalid on 2018/12/31 04:10
linux-6.6 INFO: rcu detected stall in futex origin:lts-only 1 syz, C done 6 341d 359d 2/2 fixed on 2025/10/06 10:09
linux-5.15 INFO: rcu detected stall in sys_futex 1 4 946d 1120d 0/3 auto-obsoleted due to no activity on 2024/04/10 17:08
linux-6.1 INFO: rcu detected stall in sys_futex origin:lts-only 1 syz, C done 66 1d09h 1126d 0/3 upstream: reported C repro on 2023/07/05 11:35
upstream INFO: rcu detected stall in sys_futex (6) kernel 1 10 948d 1184d 0/29 auto-obsoleted due to no activity on 2024/03/29 00:57

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=2b64/1/0x4000000000000000 softirq=25348/25349 fqs=2
	(detected by 0, t=10502 jiffies, g=29801, q=131 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8576 Comm: syz-executor.1 Not tainted 6.1.0-rc1-syzkaller-00427-gd47136c28015 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
RIP: 0010:__kasan_check_read+0x4/0x10 mm/kasan/shadow.c:31
Code: 0f 0b 48 83 c4 60 5b 5d 41 5c c3 48 05 00 80 00 00 48 89 fb 48 39 c7 0f 82 42 27 83 07 eb e1 cc cc cc cc cc cc cc 48 8b 0c 24 <89> f6 31 d2 e9 83 f8 ff ff 0f 1f 00 48 8b 0c 24 89 f6 ba 01 00 00
RSP: 0018:ffffc900001e0c58 EFLAGS: 00000056
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff815fa015
RDX: 1ffffffff1bc4328 RSI: 0000000000000008 RDI: ffffffff8de21750
RBP: 1ffff9200003c18e R08: ffffffff913a9c80 R09: 0000000000000003
R10: fffff5200003c196 R11: 0000000000000001 R12: ffffffff913a9c98
R13: ffffffff89ef0d80 R14: 0000000000000001 R15: ffff888017f84340
FS:  0000555556de6400(0000) GS:ffff8880b9b00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2e822000 CR3: 0000000073cc1000 CR4: 0000000000350ee0
Call Trace:
 <IRQ>
 instrument_atomic_read include/linux/instrumented.h:72 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 cpumask_test_cpu include/linux/cpumask.h:444 [inline]
 cpu_online include/linux/cpumask.h:1030 [inline]
 trace_lock_release include/trace/events/lock.h:69 [inline]
 lock_release+0xd5/0x810 kernel/locking/lockdep.c:5679
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline]
 _raw_spin_unlock_irqrestore+0x16/0x70 kernel/locking/spinlock.c:194
 debug_object_deactivate lib/debugobjects.c:754 [inline]
 debug_object_deactivate+0x264/0x300 lib/debugobjects.c:720
 debug_hrtimer_deactivate kernel/time/hrtimer.c:425 [inline]
 debug_deactivate kernel/time/hrtimer.c:481 [inline]
 __run_hrtimer kernel/time/hrtimer.c:1653 [inline]
 __hrtimer_run_queues+0x422/0xfb0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x31c/0x790 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1096 [inline]
 __sysvec_apic_timer_interrupt+0x17c/0x640 arch/x86/kernel/apic/apic.c:1113
 sysvec_apic_timer_interrupt+0x8e/0xc0 arch/x86/kernel/apic/apic.c:1107
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:finish_task_switch.isra.0+0x2bf/0xc80 kernel/sched/core.c:5070
Code: 8b 3a 4c 89 e7 48 c7 02 00 00 00 00 ff d1 4d 85 ff 75 bf 4c 89 e7 e8 20 f8 ff ff e8 9b e2 2f 00 fb 65 48 8b 1c 25 80 6f 02 00 <48> 8d bb 68 15 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1
RSP: 0018:ffffc90015c579f0 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffff88801f84ba80 RCX: 1ffffffff1bc4989
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff81531f15
RBP: ffffc90015c57a38 R08: 0000000000000000 R09: 0000000000000000
R10: ffffed1017347420 R11: 0000000000000001 R12: ffff8880b9b3a100
R13: ffff88801b5157c0 R14: 0000000000000000 R15: ffff8880b9b3ab38
 context_switch kernel/sched/core.c:5194 [inline]
 __schedule+0xaf1/0x53f0 kernel/sched/core.c:6503
 schedule+0xda/0x1b0 kernel/sched/core.c:6579
 futex_wait_queue+0xf5/0x1e0 kernel/futex/waitwake.c:355
 futex_wait+0x28e/0x680 kernel/futex/waitwake.c:656
 do_futex+0x1af/0x300 kernel/futex/syscalls.c:106
 __do_sys_futex kernel/futex/syscalls.c:183 [inline]
 __se_sys_futex kernel/futex/syscalls.c:164 [inline]
 __x64_sys_futex+0x1b0/0x4a0 kernel/futex/syscalls.c:164
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7ffa3588b5f9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffccc50a878 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007ffa359abf8c RCX: 00007ffa3588b5f9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007ffa359abf8c
RBP: 00007ffa359abf80 R08: 00007ffccc522080 R09: 0000000000000000
R10: 00007ffccc50a960 R11: 0000000000000246 R12: 000000000005c8ea
R13: 00007ffccc50a960 R14: 00007ffccc50a980 R15: 0000000000000032
 </TASK>
rcu: rcu_preempt kthread starved for 10498 jiffies! g29801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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:29088 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5191 [inline]
 __schedule+0xae9/0x53f0 kernel/sched/core.c:6503
 schedule+0xda/0x1b0 kernel/sched/core.c:6579
 schedule_timeout+0x14a/0x2a0 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x190/0x910 kernel/rcu/tree.c:1658
 rcu_gp_kthread+0x236/0x360 kernel/rcu/tree.c:1857
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 4007 Comm: kworker/u4:9 Not tainted 6.1.0-rc1-syzkaller-00427-gd47136c28015 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/11/2022
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline]
RIP: 0010:smp_call_function_many_cond+0x43f/0x10a0 kernel/smp.c:987
Code: e6 e8 85 e8 0a 00 45 85 e4 74 48 48 8b 04 24 49 89 c5 83 e0 07 49 c1 ed 03 49 89 c4 4d 01 fd 41 83 c4 03 e8 93 eb 0a 00 f3 90 <41> 0f b6 45 00 41 38 c4 7c 08 84 c0 0f 85 4e 0a 00 00 8b 43 08 31
RSP: 0018:ffffc90005d77970 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b9b40440 RCX: 0000000000000000
RDX: ffff88802dbf0000 RSI: ffffffff81719f5d RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000003
R13: ffffed1017368089 R14: 0000000000000001 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f51c617f1b8 CR3: 000000000bc8e000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x56/0xa0 kernel/smp.c:1155
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1311 [inline]
 text_poke_bp_batch+0x22e/0x6b0 arch/x86/kernel/alternative.c:1502
 text_poke_flush arch/x86/kernel/alternative.c:1670 [inline]
 text_poke_flush arch/x86/kernel/alternative.c:1667 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1677
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 jump_label_update+0x32f/0x410 kernel/jump_label.c:801
 static_key_enable_cpuslocked+0x1b1/0x260 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate mm/kfence/core.c:800 [inline]
 toggle_allocation_gate+0x100/0x390 mm/kfence/core.c:792
 process_one_work+0x9bf/0x1710 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e4/0x3a0 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (12):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/10/23 03:27 upstream d47136c28015 c0b80a55 .config console log report info ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_futex
2022/10/11 19:24 upstream 55be6084c8e0 1353c374 .config console log report info ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_futex
2022/10/09 00:02 upstream a6afa4199d3d aea5da89 .config console log report info ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_futex
2022/06/23 14:09 upstream de5c208d533a 912f5df7 .config console log report info ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_futex
2022/06/12 20:06 upstream 7a68065eb9cd 0d5abf15 .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_futex
2022/06/10 12:29 upstream 874c8ca1e60b 0d5abf15 .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_futex
2022/05/28 15:14 upstream 9d004b2f4fea a46af346 .config console log report info ci-upstream-kasan-gce-smack-root INFO: rcu detected stall in sys_futex
2022/04/23 20:43 upstream c00c5e1d157b 131df97d .config console log report info ci-upstream-kasan-gce-selinux-root INFO: rcu detected stall in sys_futex
2022/03/14 10:28 upstream 09688c0166e7 9e8eaa75 .config console log report info ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_futex
2022/02/21 15:05 upstream cfb92440ee71 3cd800e4 .config console log report info ci-upstream-kasan-gce-root INFO: rcu detected stall in sys_futex
2022/10/24 15:18 linux-next 4d48f589d294 23bf86af .config console log report info [disk image] [vmlinux] ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_futex
2022/09/03 15:15 linux-next e47eb90a0a9a 28811d0a .config console log report info ci-upstream-linux-next-kasan-gce-root INFO: rcu detected stall in sys_futex
* Struck through repros no longer work on HEAD.