INFO: rcu detected stall in sys_clone

Status: auto-obsoleted due to no activity on 2024/03/15 18:08
Reported-by: syzbot+d10be8518c8486101c67@syzkaller.appspotmail.com
First crash: 984d, last: 984d
▶ ▼ Similar bugs (19)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-6.6 INFO: rcu detected stall in sys_clone 1 syz, C done 8 285d 370d 2/2 fixed on 2025/12/06 23:11
linux-6.1 INFO: rcu detected stall in sys_clone 1 3 1131d 1204d 0/3 auto-obsoleted due to no activity on 2023/10/20 18:18
upstream INFO: rcu detected stall in sys_clone (2) mm 1 49 2358d 2474d 0/29 auto-closed as invalid on 2020/06/01 05:26
upstream INFO: rcu detected stall in sys_clone (4) kernel 1 1 1874d 1874d 0/29 auto-closed as invalid on 2021/09/27 17:49
upstream INFO: rcu detected stall in sys_clone (3) mm 1 2 2210d 2232d 0/29 auto-closed as invalid on 2020/10/26 22:48
upstream INFO: rcu detected stall in sys_clone (6) kasan mm 1 1 1545d 1545d 0/29 auto-closed as invalid on 2022/08/23 03:28
upstream INFO: rcu detected stall in sys_clone kernel 1 1 2531d 2531d 13/29 fixed on 2019/10/09 10:54
upstream INFO: rcu detected stall in sys_clone (8) mm 1 syz, C error 487 11h55m 871d 0/29 upstream: reported C repro on 2024/03/29 00:16
linux-4.19 INFO: rcu detected stall in sys_clone 1 2 2429d 2447d 0/1 auto-closed as invalid on 2020/04/21 05:46
upstream INFO: rcu detected stall in sys_clone (5) kernfs 1 5 1679d 1779d 0/29 closed as invalid on 2022/02/08 10:00
upstream INFO: rcu detected stall in sys_clone (7) fs 1 1 1280d 1280d 0/29 auto-obsoleted due to no activity on 2023/05/14 17:18
linux-5.15 INFO: rcu detected stall in sys_clone (2) missing-backport origin:upstream 1 syz, C done 177 4h27m 873d 0/3 upstream: reported C repro on 2024/03/27 00:16
linux-6.1 INFO: rcu detected stall in sys_clone (2) origin:upstream missing-backport 1 syz, C error 100 7d09h 879d 0/3 upstream: reported C repro on 2024/03/20 15:17
linux-6.6 INFO: rcu detected stall in sys_clone (2) 1 20 19d 251d 0/2 upstream: reported on 2025/12/09 09:13
android-5-10 BUG: soft lockup in sys_clone 1 1 769d 769d 0/2 auto-obsoleted due to no activity on 2024/10/06 12:58
android-5-10 BUG: soft lockup in sys_clone (2) 1 1 344d 344d 0/2 auto-obsoleted due to no activity on 2025/12/06 02:03
android-5-10 BUG: soft lockup in sys_clone (4) 1 1 71d 71d 0/2 premoderation: reported on 2026/06/07 05:26
android-5-10 BUG: soft lockup in sys_clone (3) 1 1 196d 196d 0/2 auto-obsoleted due to no activity on 2026/05/02 19:39
android-5-15 BUG: soft lockup in sys_clone origin:upstream 1 syz, C error 18 705d 849d 0/2 auto-obsoleted due to no activity on 2024/12/19 12:14

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4928/1:b..l P2636/1:b..l P2964/1:b..l
	(detected by 0, t=10502 jiffies, g=160493, q=101)
task:udevd           state:R  running task     stack:22176 pid: 2964 ppid:     1 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
 irqentry_exit+0x53/0x80 kernel/entry/common.c:426
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 dc 5e 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90002af77e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff9200055ef08 RCX: 1ffff9200055eea8
RDX: dffffc0000000000 RSI: ffffffff8a8b2000 RDI: ffffffff8ad87d40
RBP: ffffc90002af7930 R08: dffffc0000000000 R09: fffffbfff1f79c19
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200055ef04
R13: dffffc0000000000 R14: ffffc90002af7840 R15: 0000000000000246
 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:269
 rcu_read_lock include/linux/rcupdate.h:696 [inline]
 get_obj_cgroup_from_current+0xd3/0x2f0 mm/memcontrol.c:2919
 memcg_slab_pre_alloc_hook mm/slab.h:283 [inline]
 slab_pre_alloc_hook+0x87/0xc0 mm/slab.h:497
 slab_alloc_node mm/slub.c:3134 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x3f/0x280 mm/slub.c:3233
 prepare_creds+0x3c/0x630 kernel/cred.c:260
 copy_creds+0x146/0xca0 kernel/cred.c:365
 copy_process+0x8a7/0x3ef0 kernel/fork.c:2070
 kernel_clone+0x210/0x960 kernel/fork.c:2604
 __do_sys_clone kernel/fork.c:2721 [inline]
 __se_sys_clone kernel/fork.c:2705 [inline]
 __x64_sys_clone+0x23f/0x290 kernel/fork.c:2705
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fba62011a12
RSP: 002b:00007ffd7ef7a308 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 000055a829b7d101 RCX: 00007fba62011a12
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 0000000000000000 R08: 0000000000000000 R09: 000055a829b5b910
R10: 00007fba61f00f50 R11: 0000000000000246 R12: 000055a829b8fbe0
R13: 0000000000000000 R14: 0000000000000000 R15: 000055a829b5b910
 </TASK>
task:syz-executor.3  state:R  running task     stack:28096 pid: 2636 ppid: 32336 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6552
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6577
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
 _raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:403 [inline]
 filemap_map_pages+0x11d1/0x1560 mm/filemap.c:3344
 do_fault_around mm/memory.c:4213 [inline]
 do_read_fault mm/memory.c:4228 [inline]
 do_fault mm/memory.c:4362 [inline]
 handle_pte_fault mm/memory.c:4621 [inline]
 __handle_mm_fault mm/memory.c:4756 [inline]
 handle_mm_fault+0x341b/0x5950 mm/memory.c:4854
 do_user_addr_fault arch/x86/mm/fault.c:1397 [inline]
 handle_page_fault arch/x86/mm/fault.c:1485 [inline]
 exc_page_fault+0x271/0x740 arch/x86/mm/fault.c:1541
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:568
RIP: 0033:0x7fa5996cd95f
RSP: 002b:00007ffeb53128d8 EFLAGS: 00010283
RAX: 0000000000000390 RBX: 00007ffeb5312e40 RCX: 0000000000000000
RDX: 00007ffeb5312fc0 RSI: 0000000000000025 RDI: 00007fa59972c390
RBP: 00000000fbad8001 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa59972c390
R13: 00007ffeb5312fc0 R14: 0000000000000000 R15: 00007ffeb5312e40
 </TASK>
task:kworker/u4:16   state:R  running task     stack:20312 pid: 4928 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 preempt_schedule_notrace+0xf8/0x140 kernel/sched/core.c:6631
 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35
 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xdd/0x4f0 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:269
 rcu_read_lock include/linux/rcupdate.h:696 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc1/0x5b0 net/batman-adv/network-coding.c:723
 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310
 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: rcu_preempt kthread starved for 10572 jiffies! g160493 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:26776 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1f0 kernel/sched/core.c:6459
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1884
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:319
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 2633 Comm: syz-executor.4 Not tainted 5.15.141-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/10/2023
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2cb lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1788
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1685 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1085 [inline]
 __sysvec_apic_timer_interrupt+0x139/0x470 arch/x86/kernel/apic/apic.c:1102
 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1096
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:638
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: 81 7e f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 6e 4a 3d f7 48 89 df e8 46 9e 3e f7 e8 51 4e 61 f7 fb bf 01 00 00 00 <e8> a6 da 31 f7 65 8b 05 87 15 dd 75 85 c0 74 02 5b c3 e8 14 2d db
RSP: 0018:ffffc90006f47bc0 EFLAGS: 00000282
RAX: 11812e1961cba600 RBX: ffff888077682e40 RCX: ffffffff913c5f03
RDX: dffffc0000000000 RSI: ffffffff8a8b0d60 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff8186a8b0 R09: ffffed100eed05c9
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000021
R13: dffffc0000000000 R14: ffff8880776832d8 R15: ffff888077682e40
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0x13ee/0x14e0 kernel/signal.c:2892
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:148 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:172
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:208
 __syscall_exit_to_user_mode_work kernel/entry/common.c:290 [inline]
 syscall_exit_to_user_mode+0x5d/0x250 kernel/entry/common.c:301
 do_syscall_64+0x49/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7f6f5d309ae7
Code: 14 25 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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 b0 ff ff ff f7 d8 64 89
RSP: 002b:00007f6f5b88b0c8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f6f5d428f80 RCX: 00007f6f5d309ae9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 00007f6f5d35547a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f6f5d428f80 R15: 00007fff3adab3f8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/12/06 18:07 linux-5.15.y 9b91d36ba301 e3299f55 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in sys_clone
* Struck through repros no longer work on HEAD.