INFO: rcu detected stall in nsim_dev_trap_report_work (2)

Status: auto-obsoleted due to no activity on 2025/08/03 09:20
Reported-by: syzbot+b28ae5298ef3b122fbb8@syzkaller.appspotmail.com
First crash: 472d, last: 472d
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-5.15 INFO: rcu detected stall in nsim_dev_trap_report_work 1 2 766d 788d 0/3 auto-obsoleted due to no activity on 2024/10/13 18:52
linux-5.15 INFO: rcu detected stall in nsim_dev_trap_report_work (2) 1 1 553d 553d 0/3 auto-obsoleted due to no activity on 2025/05/14 15:54
upstream INFO: rcu detected stall in nsim_dev_trap_report_work (2) net 1 syz done 17 526d 1013d 0/29 auto-obsoleted due to no activity on 2025/09/25 13:43
upstream INFO: rcu detected stall in nsim_dev_trap_report_work net 1 syz 4 1069d 1112d 23/29 fixed on 2023/10/12 12:48
linux-6.1 INFO: rcu detected stall in nsim_dev_trap_report_work (3) 1 1 51d 51d 0/3 upstream: reported on 2026/06/20 12:13
upstream INFO: rcu detected stall in nsim_dev_trap_report_work (3) net 1 2 238d 238d 0/29 auto-obsoleted due to no activity on 2026/03/15 13:28
linux-5.15 INFO: rcu detected stall in nsim_dev_trap_report_work (3) origin:lts-only 1 syz, C error 15 12d 355d 0/3 upstream: reported C repro on 2025/08/20 06:57
linux-6.1 INFO: rcu detected stall in nsim_dev_trap_report_work 1 2 819d 864d 0/3 auto-obsoleted due to no activity on 2024/08/22 01:13

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (1 GPs behind) idle=f5b4/1/0x4000000000000000 softirq=55205/55206 fqs=1
	(detected by 0, t=10505 jiffies, g=81849, q=32 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 8202 Comm: kworker/u4:18 Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline]
RIP: 0010:mark_lock+0xa2/0x340 kernel/locking/lockdep.c:4606
Code: 00 8b 1b 81 e3 ff 1f 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 60 82 2b 91 be 08 00 00 00 e8 d6 d6 76 00 48 0f a3 1d 8e ab c0 0f <73> 11 48 8d 04 5b 48 c1 e0 06 48 8d 98 20 01 c4 90 eb 23 48 c7 c0
RSP: 0018:ffffc900001e09b8 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffffffff816ad6ca
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff912b8260
RBP: 0000000000000008 R08: dffffc0000000000 R09: fffffbfff225704d
R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88802c7de418
R13: dffffc0000000000 R14: 0000000000000100 R15: ffff88802c7de4e8
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c36e9de CR3: 00000000491e6000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000097 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 mark_usage kernel/locking/lockdep.c:4549 [inline]
 __lock_acquire+0xc6a/0x1f80 kernel/locking/lockdep.c:5003
 lock_acquire+0x1f8/0x5a0 kernel/locking/lockdep.c:5662
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0xd1/0x120 kernel/locking/spinlock.c:162
 debug_object_deactivate+0x63/0x380 lib/debugobjects.c:753
 debug_hrtimer_deactivate kernel/time/hrtimer.c:416 [inline]
 debug_deactivate+0x1d/0x280 kernel/time/hrtimer.c:472
 __run_hrtimer kernel/time/hrtimer.c:1659 [inline]
 __hrtimer_run_queues+0x334/0xe50 kernel/time/hrtimer.c:1755
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1817
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline]
 __sysvec_apic_timer_interrupt+0x158/0x5b0 arch/x86/kernel/apic/apic.c:1124
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:49 [inline]
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:178 [inline]
RIP: 0010:unwind_next_frame+0x4c3/0x2220 arch/x86/kernel/unwind_orc.c:448
Code: 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 89 d9 80 e1 07 80 c1 03 38 c1 7c cd
RSP: 0018:ffffc9000361f5c0 EFLAGS: 00000202
RAX: ffffffff8eb76e2c RBX: ffffffff8eb76e30 RCX: ffffffff8eb76e34
RDX: ffffffff8f27da54 RSI: ffffffff81e17fbb RDI: dffffc0000000000
RBP: ffffffff8eb76e2c R08: 0000000000000011 R09: ffffc9000361f790
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8eb76e28
R13: ffffffff81e17fba R14: ffffffff8eb76e08 R15: ffffffff8eb76e2c
 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_slab_alloc+0x65/0x70 mm/kasan/common.c:328
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook+0x52/0x3a0 mm/slab.h:737
 slab_alloc_node mm/slub.c:3398 [inline]
 kmem_cache_alloc_node+0x136/0x310 mm/slub.c:3443
 __alloc_skb+0xd3/0x2c0 net/core/skbuff.c:505
 alloc_skb include/linux/skbuff.h:1271 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline]
 nsim_dev_trap_report_work+0x24c/0xab0 drivers/net/netdevsim/dev.c:851
 process_one_work+0x917/0x1260 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:295
 </TASK>
rcu: rcu_preempt kthread starved for 10500 jiffies! g81849 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:26200 pid:16    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5244 [inline]
 __schedule+0x143f/0x4570 kernel/sched/core.c:6561
 schedule+0xbf/0x180 kernel/sched/core.c:6637
 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965
 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706
 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905
 kthread+0x28d/0x320 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 4361 Comm: kworker/u4:10 Not tainted 6.1.134-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline]
RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998
Code: 2f 44 89 ee 83 e6 01 31 ff e8 6e 47 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 f9 43 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:ffffc9000485f5a0 EFLAGS: 00000293
RAX: ffffffff817f08c9 RBX: 1ffff110171e81a1 RCX: ffff888028ecbb80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000485f980 R08: ffffffff817f0892 R09: fffffbfff225704d
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8f40d08
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c301e73 CR3: 000000000d08e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:1334 [inline]
 text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534
 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline]
 text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732
 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146
 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:207
 static_key_enable+0x16/0x20 kernel/jump_label.c:220
 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:805
 process_one_work+0x917/0x1260 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:295
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/04/25 09:19 linux-6.1.y 420102835862 e3715315 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-6-1-kasan INFO: rcu detected stall in nsim_dev_trap_report_work
* Struck through repros no longer work on HEAD.