INFO: rcu detected stall in nsim_dev_psample_report_work (2)

Status: auto-obsoleted due to no activity on 2026/07/21 02:52
Subsystems: mm
Labels: prio:high
[Documentation on labels]
First crash: 110d, last: 110d
✨ AI Jobs (1)
ID Workflow Result Correct Bug Created Started Finished Revision
7deb846b assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ❌ NetworkTrigger: ✅ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ✅ VMGuestTrigger: ❌ VMHostTrigger: ❌ INFO: rcu detected stall in nsim_dev_psample_report_work (2) 2026/05/17 15:54 2026/05/17 15:54 2026/05/17 16:44 de5aae85
Similar bugs (1)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: rcu detected stall in nsim_dev_psample_report_work mm 1 1 371d 371d 0/29 auto-obsoleted due to no activity on 2025/11/02 18:58

Sample crash report:
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P84/1:b..l P2/1:b..l P1229/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=389213, q=634 ncpus=1)
task:kworker/0:3     state:R  running task     stack:25896 pid:1229  tgid:1229  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: events nsim_dev_psample_report_work
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <c3> cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db ff da f5 cc
RSP: 0018:ffffc90005c9f840 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 00000000000aff5b RCX: ffffffff828188aa
RDX: ffff88802a5edc40 RSI: ffffffff828188be RDI: ffff88802a5edc40
RBP: ffff88801d780000 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: 00000000025a03a1 R14: 0000000000000000 R15: 0000000004fa047c
 page_ext_invalid mm/page_ext.c:249 [inline]
 lookup_page_ext+0x8e/0x100 mm/page_ext.c:265
 page_ext_iter_begin include/linux/page_ext.h:133 [inline]
 __update_page_owner_free_handle.isra.0+0xa4/0x4d0 mm/page_owner.c:284
 __reset_page_owner+0x93/0x190 mm/page_owner.c:321
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 __do_kmalloc_node mm/slub.c:5294 [inline]
 __kmalloc_node_track_caller_noprof+0x2ba/0x850 mm/slub.c:5403
 kmalloc_reserve+0xe8/0x350 net/core/skbuff.c:635
 __alloc_skb+0x185/0x710 net/core/skbuff.c:713
 alloc_skb include/linux/skbuff.h:1383 [inline]
 nsim_dev_psample_skb_build drivers/net/netdevsim/psample.c:46 [inline]
 nsim_dev_psample_report_work+0x9b/0xc50 drivers/net/netdevsim/psample.c:120
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:kthreadd        state:R  running task     stack:26528 pid:2     tgid:2     ppid:0      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5893
Code: ff 65 0f c1 05 db 59 2f 12 83 f8 01 0f 85 28 01 00 00 9c 58 f6 c4 02 0f 85 13 01 00 00 41 f7 c6 00 02 00 00 0f 85 c0 00 00 00 <48> 8b 44 24 10 65 48 2b 05 2d 12 2f 12 0f 85 4e 01 00 00 48 83 c4
RSP: 0018:ffffc90000077580 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e7e5260 RCX: ffffc9000007758c
RDX: 0000000000000001 RSI: ffffffff8df2fec2 RDI: ffffffff8c1c1080
RBP: ffffffff81b851ae R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000016a08 R12: ffff88801de9bd80
R13: ffffc90000077638 R14: 0000000000000202 R15: 0000000000000002
 rcu_lock_release include/linux/rcupdate.h:310 [inline]
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0x3c3/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x162/0x1e0 mm/page_owner.c:165
 __reset_page_owner+0x84/0x190 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0x747/0x1040 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
 copy_signal kernel/fork.c:1703 [inline]
 copy_process+0x2c51/0x7fa0 kernel/fork.c:2259
 kernel_clone+0x12e/0x9c0 kernel/fork.c:2723
 kernel_thread+0xdb/0x120 kernel/fork.c:2784
 create_kthread kernel/kthread.c:459 [inline]
 kthreadd+0x498/0x7a0 kernel/kthread.c:817
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
task:kswapd0         state:R  running task     stack:26144 pid:84    tgid:84    ppid:2      task_flags:0x220840 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 3b 19 2f 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 46 87 f7 0e 0f 82 a4 02 00 00 8b 35 ae ba f7 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd 18 2f 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc9000251ed80 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8df2fec2 RDI: ffffffff8c1c1080
RBP: ffffffff8e7e5260 R08: 000000001a670176 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
 unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x162/0x1e0 mm/page_owner.c:165
 __reset_page_owner+0x84/0x190 mm/page_owner.c:320
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
 shrink_folio_list+0x473d/0x60c0 mm/vmscan.c:1516
 evict_folios+0x846/0x20c0 mm/vmscan.c:4854
 try_to_shrink_lruvec+0x57c/0xa20 mm/vmscan.c:5009
 shrink_one+0x307/0x7f0 mm/vmscan.c:5069
 shrink_many mm/vmscan.c:5132 [inline]
 lru_gen_shrink_node mm/vmscan.c:5210 [inline]
 shrink_node+0x2673/0x3dc0 mm/vmscan.c:6198
 kswapd_shrink_node mm/vmscan.c:7052 [inline]
 balance_pgdat+0xaaf/0x1ac0 mm/vmscan.c:7228
 kswapd+0x557/0xb60 mm/vmscan.c:7501
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread starved for 1258 jiffies! g389213 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:27752 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x10e9/0x6820 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0xdd/0x390 kernel/sched/core.c:7282
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 3427 Comm: kworker/R-bat_e Tainted: G     U    I  L      syzkaller #0 PREEMPT(full) 
Tainted: [U]=USER, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Workqueue: bat_events batadv_tt_purge
RIP: 0010:stack_trace_consume_entry+0x93/0x170 kernel/stacktrace.c:89
Code: 00 00 00 fc ff df 48 8d 7b 0c 48 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 98 00 00 00 <8b> 43 0c 85 c0 75 57 48 b8 00 00 00 00 00 fc ff df 48 89 da 48 c1
RSP: 0018:ffffc90000006d18 EFLAGS: 00000246
RAX: 0000000000000007 RBX: ffffc90000006df8 RCX: ffffc90000006c8c
RDX: 0000000000000000 RSI: ffffffff81d19780 RDI: ffffc90000006e04
RBP: 000000000000001d R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000000cf43 R12: ffffffff81f32c30
R13: ffffc90000006df8 R14: 0000000000000000 R15: ffff88802ae50000
FS:  0000000000000000(0000) GS:ffff8881242e2000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555810974e8 CR3: 000000007dc8e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 arch_stack_walk+0x88/0xf0 arch/x86/kernel/stacktrace.c:27
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
 kasan_save_track+0x14/0x30 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x241/0x6e0 mm/slub.c:4905
 skb_ext_maybe_cow net/core/skbuff.c:7063 [inline]
 skb_ext_add+0xfa/0x810 net/core/skbuff.c:7138
 nf_bridge_unshare net/bridge/br_netfilter_hooks.c:170 [inline]
 br_nf_forward_ip.part.0+0x28/0x820 net/bridge/br_netfilter_hooks.c:682
 br_nf_forward_ip net/bridge/br_netfilter_hooks.c:677 [inline]
 br_nf_forward+0xfe5/0x19f0 net/bridge/br_netfilter_hooks.c:774
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
 nf_hook include/linux/netfilter.h:273 [inline]
 NF_HOOK include/linux/netfilter.h:316 [inline]
 __br_forward+0x2f7/0x970 net/bridge/br_forward.c:115
 deliver_clone net/bridge/br_forward.c:131 [inline]
 maybe_deliver+0xf0/0x180 net/bridge/br_forward.c:191
 br_flood+0x193/0x650 net/bridge/br_forward.c:238
 br_handle_frame_finish+0xff4/0x1f60 net/bridge/br_input.c:229
 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1161
 br_nf_pre_routing_finish_ipv6+0x659/0xdd0 net/bridge/br_netfilter_ipv6.c:153
 NF_HOOK include/linux/netfilter.h:318 [inline]
 br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:183
 br_nf_pre_routing+0x90f/0x1560 net/bridge/br_netfilter_hooks.c:509
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
 br_handle_frame+0xcdd/0x1520 net/bridge/br_input.c:442
 __netif_receive_skb_core.constprop.0+0x6c5/0x3530 net/core/dev.c:6096
 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6207
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6322
 process_backlog+0x37a/0x1580 net/core/dev.c:6673
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7737
 napi_poll net/core/dev.c:7800 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:7957
 handle_softirqs+0x1ea/0xa00 kernel/softirq.c:622
 do_softirq kernel/softirq.c:523 [inline]
 do_softirq+0xac/0xe0 kernel/softirq.c:510
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_tt_global_purge net/batman-adv/translation-table.c:2255 [inline]
 batadv_tt_purge+0x25d/0xbd0 net/batman-adv/translation-table.c:3515
 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302
 process_scheduled_works kernel/workqueue.c:3385 [inline]
 rescuer_thread+0x905/0x14a0 kernel/workqueue.c:3609
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
net_ratelimit: 4222 callbacks suppressed
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:76:d6:62:36:57:b6, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:9a:6a:95:ae:0f:3c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
net_ratelimit: 7188 callbacks suppressed
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:aa:aa:aa:aa:aa:0c, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:76:d6:62:36:57:b6, vlan:0)
bridge0: received packet on veth0_to_bridge with own address as source address (addr:9a:6a:95:ae:0f:3c, vlan:0)
bridge0: received packet on bridge_slave_0 with own address as source address (addr:aa:aa:aa:aa:aa:1b, vlan:0)

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/04/22 02:42 upstream 6596a02b2078 0b6ab7ec .config console log report info [disk image] [vmlinux] [kernel image] ci-qemu-gce-upstream-auto INFO: rcu detected stall in nsim_dev_psample_report_work
* Struck through repros no longer work on HEAD.