INFO: rcu detected stall in unwind_next_frame

Status: auto-obsoleted due to no activity on 2024/01/21 04:23
Reported-by: syzbot+6009fa7b9b6d065a994e@syzkaller.appspotmail.com
First crash: 1014d, last: 1014d
▶ ▼ Similar bugs (9)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in unwind_next_frame (2) kernel 1 1 1063d 1063d 0/29 auto-obsoleted due to no activity on 2023/10/24 10:24
linux-6.1 INFO: rcu detected stall in unwind_next_frame (2) 1 1 849d 849d 0/3 auto-obsoleted due to no activity on 2024/07/04 19:31
upstream INFO: rcu detected stall in unwind_next_frame (5) prio:low ext4 1 C error error 55 5d00h 283d 0/29 upstream: reported C repro on 2025/10/14 01:28
linux-6.1 INFO: rcu detected stall in unwind_next_frame (3) 1 2 29d 71d 0/3 upstream: reported on 2026/05/13 02:27
upstream INFO: rcu detected stall in unwind_next_frame (3) kernel 1 1 996d 996d 0/29 auto-obsoleted due to no activity on 2024/01/29 09:37
upstream INFO: rcu detected stall in unwind_next_frame (4) mm 1 7 634d 767d 0/29 auto-obsoleted due to no activity on 2025/01/25 06:35
linux-5.15 INFO: rcu detected stall in unwind_next_frame 1 1 334d 334d 0/3 auto-obsoleted due to no activity on 2025/12/01 20:02
linux-6.6 INFO: rcu detected stall in unwind_next_frame 1 1 15d 15d 0/2 upstream: reported on 2026/07/08 12:08
upstream INFO: rcu detected stall in unwind_next_frame kernel 1 2 2985d 2989d 8/29 fixed on 2018/07/09 18:05

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=81ac/1/0x4000000000000000 softirq=88575/88576 fqs=0
	(detected by 1, t=10505 jiffies, g=130813, q=202 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 7697 Comm: kworker/u4:25 Not tainted 6.1.57-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet
RIP: 0010:__lock_acquire+0x469/0x1f80 kernel/locking/lockdep.c:4996
Code: 85 e5 12 00 00 44 8b b4 24 d8 00 00 00 48 8b 44 24 08 44 89 20 48 8b 44 24 20 48 8d 5c c6 24 48 89 d8 48 c1 e8 03 0f b6 04 10 <84> c0 4c 8b 64 24 18 0f 85 e3 12 00 00 44 89 33 44 89 fb 48 89 d8
RSP: 0018:ffffc90000006ce0 EFLAGS: 00000803
RAX: 0000000000000000 RBX: ffff888017b264bc RCX: 0000000000080000
RDX: dffffc0000000000 RSI: ffff888017b26420 RDI: 000000000000605d
RBP: ffff888017b26404 R08: 0000000000000001 R09: 0000000000000001
R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000000c605d
R13: ffff888017b25940 R14: 0000000000000000 R15: 000000000000005d
FS:  0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f799d976bf8 CR3: 000000003bf19000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <NMI>
 </NMI>
 <IRQ>
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5661
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
 _raw_spin_lock_irq+0xcf/0x110 kernel/locking/spinlock.c:170
 __run_hrtimer kernel/time/hrtimer.c:1689 [inline]
 __hrtimer_run_queues+0x6d3/0xe50 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1811
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline]
 __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112
 sysvec_apic_timer_interrupt+0x3e/0xb0 arch/x86/kernel/apic/apic.c:1106
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:649
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:52 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x4b7/0x2220 arch/x86/kernel/unwind_orc.c:448
Code: 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 84 c0 75 27 48 63 03 48 01 d8 48 8d 4b 04 4c 39 e8 4c 0f 46 f9 <48> 8d 43 fc 48 0f 47 e8 4c 0f 46 e3 49 39 ef 76 a9 e9 a7 fd ff ff
RSP: 0018:ffffc90000007320 EFLAGS: 00000206
RAX: ffffffff81e0c3b8 RBX: ffffffff8e8a0fb4 RCX: ffffffff8e8a0fb8
RDX: ffffffff8ef886a4 RSI: ffffffff81e0c302 RDI: dffffc0000000000
RBP: ffffffff8e8a0fb8 R08: 0000000000000011 R09: ffffc900000074f0
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8e8a0fb0
R13: ffffffff81e0c301 R14: ffffffff8e8a0fb0 R15: ffffffff8e8a0fb0
 arch_stack_walk+0x10d/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x27/0x40 mm/kasan/generic.c:516
 ____kasan_slab_free+0xd6/0x120 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:177 [inline]
 slab_free_hook mm/slub.c:1724 [inline]
 slab_free_freelist_hook mm/slub.c:1750 [inline]
 slab_free mm/slub.c:3661 [inline]
 kmem_cache_free+0x292/0x510 mm/slub.c:3683
 __netif_receive_skb_core+0x398a/0x41d0 net/core/dev.c:5470
 __netif_receive_skb_one_core net/core/dev.c:5494 [inline]
 __netif_receive_skb+0x11c/0x530 net/core/dev.c:5610
 process_backlog+0x381/0x760 net/core/dev.c:5938
 __napi_poll+0xc7/0x470 net/core/dev.c:6505
 napi_poll net/core/dev.c:6572 [inline]
 net_rx_action+0x70f/0xeb0 net/core/dev.c:6683
 __do_softirq+0x2e9/0xa4c kernel/softirq.c:571
 do_softirq+0x162/0x240 kernel/softirq.c:472
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x1b1/0x1f0 kernel/softirq.c:396
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_read_unlock_bh include/linux/rcupdate.h:817 [inline]
 __dev_queue_xmit+0x1790/0x3cf0 net/core/dev.c:4288
 dev_queue_xmit include/linux/netdevice.h:3021 [inline]
 batadv_send_skb_packet+0x409/0x660 net/batman-adv/send.c:108
 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:393 [inline]
 batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:421 [inline]
 batadv_iv_send_outstanding_bat_ogm_packet+0x66f/0x800 net/batman-adv/bat_iv_ogm.c:1701
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>
rcu: rcu_preempt kthread starved for 10505 jiffies! g130813 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:26680 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5241 [inline]
 __schedule+0x142d/0x4550 kernel/sched/core.c:6554
 schedule+0xbf/0x180 kernel/sched/core.c:6630
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1935
 rcu_gp_fqs_loop+0x2c2/0x1010 kernel/rcu/tree.c:1661
 rcu_gp_kthread+0xa3/0x3a0 kernel/rcu/tree.c:1860
 kthread+0x28d/0x320 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: 1 PID: 21597 Comm: kworker/u4:11 Not tainted 6.1.57-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/06/2023
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:413 [inline]
RIP: 0010:smp_call_function_many_cond+0x1f62/0x33d0 kernel/smp.c:987
Code: 2f 44 89 ee 83 e6 01 31 ff e8 da 35 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 65 32 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff
RSP: 0018:ffffc900053275a0 EFLAGS: 00000293
RAX: ffffffff817f3ead RBX: 1ffff1101730841d RCX: ffff888014680000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90005327980 R08: ffffffff817f3e76 R09: fffffbfff2093045
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b98420e8
FS:  0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8b44ac56be CR3: 000000000ce8e000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1155
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1316 [inline]
 text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1516
 text_poke_flush arch/x86/kernel/alternative.c:1707 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1714
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:177
 static_key_enable+0x16/0x20 kernel/jump_label.c:190
 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804
 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292
 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:306
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/10/13 04:22 linux-6.1.y 082280fe94a0 6388bc36 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in unwind_next_frame
* Struck through repros no longer work on HEAD.