rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=177017, q=1320 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10118 (4295037798-4295027680), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10119 jiffies! g177017 f0x2 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:26848 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 26913 Comm: udevd Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:deref_stack_reg+0x18e/0x220 arch/x86/kernel/unwind_orc.c:422
Code: 20 c2 20 ca 80 fa 01 75 46 49 8d 40 08 4c 39 e0 0f 97 c1 4c 39 f0 0f 96 c0 20 c8 3c 01 75 30 4c 89 c7 49 89 f7 e8 12 07 00 00 <49> 89 c6 48 8b 5c 24 08 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08
RSP: 0018:ffffc90000a07df8 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff92000140fdd RCX: 0000000000000001
RDX: ffffc90000a07f28 RSI: dffffc0000000000 RDI: ffffc90000a08fc0
RBP: ffffc90000a01000 R08: ffffc90000a08fc0 R09: 0000000000000000
R10: ffffc90000a07f38 R11: fffff52000140fe9 R12: 1ffff92000140fde
R13: 1ffff92000140fdf R14: ffffc90000a09000 R15: dffffc0000000000
FS: 0000000000000000(0000) GS:ffff888125049000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055dcfc609660 CR3: 000000007f7d2000 CR4: 00000000003526f0
Call Trace:
unwind_next_frame+0x19bd/0x2550 arch/x86/kernel/unwind_orc.c:-1
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4584 [inline]
slab_alloc_node mm/slub.c:4917 [inline]
kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931
skb_clone+0x212/0x3a0 net/core/skbuff.c:2116
deliver_clone net/bridge/br_forward.c:125 [inline]
maybe_deliver net/bridge/br_forward.c:191 [inline]
br_flood+0x3c3/0x8d0 net/bridge/br_forward.c:245
br_handle_frame_finish+0x1175/0x1990 net/bridge/br_input.c:229
br_nf_hook_thresh+0x3dd/0x4c0 net/bridge/br_netfilter_hooks.c:-1
br_nf_pre_routing_finish_ipv6+0x90c/0xc40 net/bridge/br_netfilter_ipv6.c:-1
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x382/0x6f0 net/bridge/br_netfilter_ipv6.c:183
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_bridge_pre net/bridge/br_input.c:291 [inline]
br_handle_frame+0x127f/0x1510 net/bridge/br_input.c:442
__netif_receive_skb_core+0x989/0x30b0 net/core/dev.c:6103
__netif_receive_skb_one_core net/core/dev.c:6214 [inline]
__netif_receive_skb net/core/dev.c:6329 [inline]
process_backlog+0x706/0x1860 net/core/dev.c:6680
__napi_poll+0xaa/0x330 net/core/dev.c:7739
napi_poll net/core/dev.c:7802 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:7959
handle_softirqs+0x225/0x840 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:finish_task_switch+0x417/0xc60 kernel/sched/core.c:5361
Code: 04 00 00 41 c7 84 24 20 0e 00 00 00 00 00 00 0f 1f 44 00 00 49 83 c4 48 4c 89 e7 e8 53 8c 3f 0a e8 6e aa 39 00 fb 4c 8b 65 c8 <49> 8d bc 24 f8 16 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0
RSP: 0018:ffffc90005dff020 EFLAGS: 00000202
RAX: 000000000000badf RBX: ffff8880b873bf20 RCX: 0000000080000001
RDX: 0000000000000006 RSI: ffffffff8e22cd57 RDI: ffffffff8c4bbf80
RBP: ffffc90005dff070 R08: ffffffff90578f37 R09: 1ffffffff20af1e6
R10: dffffc0000000000 R11: fffffbfff20af1e7 R12: ffff8880771d9f00
R13: ffff8880b873bee8 R14: dffffc0000000000 R15: 1ffff110170e77e4
context_switch kernel/sched/core.c:5513 [inline]
__schedule+0x17e1/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x2d7/0x3c0 kernel/locking/lockdep.c:5893
Code: cb ca 11 00 00 00 00 eb b5 e8 b5 7b 2f 0a f7 c3 00 02 00 00 74 b9 65 48 8b 05 45 86 ca 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d c2 37 b8
RSP: 0018:ffffc90005dff3a8 EFLAGS: 00000282
RAX: d72fff1f4d2ffd00 RBX: 0000000000000206 RCX: 0000000000000046
RDX: 0000000000000002 RSI: ffffffff8e4b233f RDI: ffffffff8c4bbf80
RBP: ffff8880771daaf0 R08: ffffc90005dfff38 R09: 0000000000000000
R10: ffffc90005dff4d8 R11: fffff52000bbfe9d R12: 0000000000000002
R13: 0000000000000002 R14: ffffffff8eb59c60 R15: ffff8880771d9f00
rcu_lock_release include/linux/rcupdate.h:310 [inline]
rcu_read_unlock include/linux/rcupdate.h:871 [inline]
class_rcu_destructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2677 [inline]
slab_free mm/slub.c:6377 [inline]
kmem_cache_free+0x182/0x650 mm/slub.c:6504
anon_vma_chain_free mm/rmap.c:147 [inline]
unlink_anon_vmas+0x366/0x730 mm/rmap.c:514
free_pgtables+0x836/0xb70 mm/memory.c:414
exit_mmap+0x4aa/0x9f0 mm/mmap.c:1312
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:615
do_exit+0x6cd/0x2360 kernel/exit.c:997
do_group_exit+0x22d/0x2f0 kernel/exit.c:1152
__do_sys_exit_group kernel/exit.c:1163 [inline]
__se_sys_exit_group kernel/exit.c:1161 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1161
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1687cf16c5
Code: Unable to access opcode bytes at 0x7f1687cf169b.
RSP: 002b:00007fffbe6dc958 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00005617563976b0 RCX: 00007f1687cf16c5
RDX: 00000000000000e7 RSI: fffffffffffffe68 RDI: 0000000000000000
RBP: 000056175638f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fffbe6dc9a0 R14: 0000000000000000 R15: 0000000000000000