syzbot
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
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)
* Struck through repros no longer work on HEAD.