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INFO: rcu detected stall in nsim_dev_trap_report_work (3)

Status: upstream: reported on 2025/08/20 06:57
Reported-by: syzbot+adf3d9d216d554ccac29@syzkaller.appspotmail.com
First crash: 1d16h, last: 1d16h
▶ ▼ Similar bugs (6)
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 412d 434d 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 199d 199d 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 171d 659d 0/29 upstream: reported syz repro on 2023/11/01 08:50
upstream INFO: rcu detected stall in nsim_dev_trap_report_work net 1 syz 4 714d 757d 23/29 fixed on 2023/10/12 12:48
linux-6.1 INFO: rcu detected stall in nsim_dev_trap_report_work 1 2 464d 509d 0/3 auto-obsoleted due to no activity on 2024/08/22 01:13
linux-6.1 INFO: rcu detected stall in nsim_dev_trap_report_work (2) 1 1 118d 118d 0/3 auto-obsoleted due to no activity on 2025/08/03 09:20

Sample crash report:
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=39f/1/0x4000000000000000 softirq=15182/15182 fqs=10 
	(detected by 0, t=10502 jiffies, g=20265, q=282)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 1109 Comm: kworker/1:2 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:436 [inline]
RIP: 0010:lock_is_held_type+0x100/0x190 kernel/locking/lockdep.c:5667
Code: ff 74 16 89 e9 31 c0 41 f6 47 22 03 0f 95 c0 31 ed 39 c1 40 0f 94 c5 eb 05 bd 01 00 00 00 48 c7 c7 60 28 0b 8a e8 c0 0d 00 00 <b8> ff ff ff ff 65 0f c1 05 13 48 5a 76 83 f8 01 75 40 48 c7 04 24
RSP: 0018:ffffc90000dd0c38 EFLAGS: 00000082
RAX: 0000000000000001 RBX: ffff888020e55940 RCX: 11301bcc93a80800
RDX: 0000000000010000 RSI: ffffffff8a0b2860 RDI: ffffffff8a599340
RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000003
R10: fffff520001ba180 R11: 1ffff920001ba180 R12: 0000000000000004
R13: 0000000000000046 R14: ffff88805e40a300 R15: ffff888020e564d0
FS:  0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c249de5 CR3: 000000007b7a6000 CR4: 00000000003526e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 lock_is_held include/linux/lockdep.h:287 [inline]
 advance_sched+0x141/0x940 net/sched/sch_taprio.c:721
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:preempt_count_sub+0x2c/0x160 kernel/sched/core.c:5517
Code: 48 bb 00 00 00 00 00 fc ff df 48 c7 c0 60 df 0b 96 48 c1 e8 03 0f b6 04 18 84 c0 0f 85 bd 00 00 00 83 3d 16 6f ba 14 00 75 25 <65> 8b 05 75 ff b0 7e 89 c1 81 e1 ff ff ff 7f 39 cf 7f 25 81 ff ff
RSP: 0018:ffffc90004767650 EFLAGS: 00000246
RAX: 0000000000000004 RBX: dffffc0000000000 RCX: ffffffff960bdf03
RDX: ffffc90004767701 RSI: ffffc90004767778 RDI: 0000000000000001
RBP: ffffc900047677d0 R08: dffffc0000000000 R09: ffffc900047677d8
R10: fffff520008ecefd R11: 1ffff920008ecefb R12: ffffc90004760000
R13: dffffc0000000000 R14: ffffc90004767798 R15: ffffc90004767788
 unwind_next_frame+0x1296/0x1d90 arch/x86/kernel/unwind_orc.c:616
 __unwind_start+0x5bb/0x740 arch/x86/kernel/unwind_orc.c:704
 unwind_start arch/x86/include/asm/unwind.h:60 [inline]
 arch_stack_walk+0xda/0x140 arch/x86/kernel/stacktrace.c:24
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xb5/0xf0 mm/kasan/common.c:522
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:664 [inline]
 nsim_dev_trap_report drivers/net/netdevsim/dev.c:721 [inline]
 nsim_dev_trap_report_work+0x2a1/0xb40 drivers/net/netdevsim/dev.c:762
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread starved for 10450 jiffies! g20265 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:28128 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 6353 Comm: syz.9.455 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 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:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_single+0x212/0x490 kernel/smp.c:758
Code: 48 44 89 f6 83 e6 01 31 ff e8 0a 5c 0b 00 41 83 e6 01 49 bc 00 00 00 00 00 fc ff df 75 0a e8 95 58 0b 00 e9 a3 00 00 00 f3 90 <f7> 44 24 48 01 00 00 00 0f 84 8e 00 00 00 e8 7b 58 0b 00 eb e9 e8
RSP: 0018:ffffc900015bf900 EFLAGS: 00000246
RAX: ffffffff816c6ba5 RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000fe21000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc900015bf9f0 R08: dffffc0000000000 R09: ffffed1017227679
R10: ffffed1017227679 R11: 1ffff11017227678 R12: dffffc0000000000
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff920002b7f24
 loaded_vmcs_clear arch/x86/kvm/vmx/vmx.c:723 [inline]
 vmx_vcpu_load_vmcs+0x12a/0x780 arch/x86/kvm/vmx/vmx.c:1315
 vmx_vcpu_load+0x1a/0x80 arch/x86/kvm/vmx/vmx.c:1380
 kvm_arch_vcpu_load+0x190/0x770 arch/x86/kvm/x86.c:4385
 vcpu_load+0x4e/0x80 virt/kvm/kvm_main.c:209
 kvm_arch_vcpu_ioctl_run+0x53/0x1f40 arch/x86/kvm/x86.c:10337
 kvm_vcpu_ioctl+0x887/0xb80 virt/kvm/kvm_main.c:3894
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:874 [inline]
 __se_sys_ioctl+0xfa/0x170 fs/ioctl.c:860
 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: 0033:0x7f5a9b788be9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f5a999ae038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f5a9b9b0180 RCX: 00007f5a9b788be9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 0000000000000005
RBP: 00007f5a9b80be19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5a9b9b0218 R14: 00007f5a9b9b0180 R15: 00007fff8531b8b8
 </TASK>

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/08/20 06:56 linux-5.15.y c79648372d02 79512909 .config console log report info [disk image] [vmlinux] [kernel image] ci2-linux-5-15-kasan INFO: rcu detected stall in nsim_dev_trap_report_work
* Struck through repros no longer work on HEAD.