rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: (detected by 1, t=10502 jiffies, g=35941, q=2633 ncpus=2)
rcu: All QSes seen, last rcu_preempt kthread activity 10317 (4294983247-4294972930), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10318 jiffies! g35941 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5295 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6908
__schedule_loop kernel/sched/core.c:6990 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7005
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:467
ret_from_fork+0x754/0xd80 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:109 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5864 [inline]
RIP: 0010:lock_acquire+0x17c/0x380 kernel/locking/lockdep.c:5825
Code: bd 00 00 00 65 8b 05 eb 0f 29 12 85 c0 0f 85 ae 00 00 00 65 48 8b 05 6b c8 28 12 8b 90 54 0b 00 00 85 d2 0f 85 98 00 00 00 9c <8f> 04 24 fa 48 c7 c7 ff d0 f6 8d e8 44 fd a8 09 45 89 e8 44 89 e1
RSP: 0018:ffffc90000a07a20 EFLAGS: 00000246
RAX: ffff88801e6e0000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff81b7aaf1 RDI: fffffbfff1cfd244
RBP: ffffffff8e7e9220 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000200 R11: 000000000000aeb2 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812444e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f59d5548700 CR3: 0000000033f5c000 CR4: 00000000003526f0
Call Trace:
rcu_lock_acquire include/linux/rcupdate.h:312 [inline]
rcu_read_lock include/linux/rcupdate.h:850 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0xd1/0x1ea0 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
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_save_track+0x14/0x30 mm/kasan/common.c:78
kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2692 [inline]
slab_free mm/slub.c:6143 [inline]
kmem_cache_free+0x124/0x6a0 mm/slub.c:6273
__skb_ext_put+0x102/0x2f0 net/core/skbuff.c:7252
skb_ext_reset include/linux/skbuff.h:5090 [inline]
skb_ext_reset include/linux/skbuff.h:5087 [inline]
skb_release_head_state+0x2c8/0x400 net/core/skbuff.c:1195
skb_release_all net/core/skbuff.c:1201 [inline]
__kfree_skb net/core/skbuff.c:1217 [inline]
sk_skb_reason_drop+0xc4/0x1b0 net/core/skbuff.c:1255
kfree_skb_reason include/linux/skbuff.h:1322 [inline]
kfree_skb include/linux/skbuff.h:1331 [inline]
ip6_mc_input+0x832/0xf50 net/ipv6/ip6_input.c:593
dst_input include/net/dst.h:480 [inline]
dst_input include/net/dst.h:478 [inline]
ip6_rcv_finish+0x3b1/0x550 net/ipv6/ip6_input.c:79
ip_sabotage_in+0x21e/0x290 net/bridge/br_netfilter_hooks.c:990
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ipv6_rcv+0xa4/0x610 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6167
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6280
netif_receive_skb_internal net/core/dev.c:6366 [inline]
netif_receive_skb+0x139/0x820 net/core/dev.c:6425
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
br_pass_frame_up+0x346/0x490 net/bridge/br_input.c:70
br_handle_frame_finish+0x84f/0x1f00 net/bridge/br_input.c:235
br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167
br_nf_pre_routing_finish_ipv6+0x769/0xfb0 net/bridge/br_netfilter_ipv6.c:154
NF_HOOK include/linux/netfilter.h:318 [inline]
br_nf_pre_routing_ipv6+0x39c/0x8b0 net/bridge/br_netfilter_ipv6.c:184
br_nf_pre_routing+0x93b/0x1510 net/bridge/br_netfilter_hooks.c:508
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+0x6c5/0x3550 net/core/dev.c:6054
__netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6165
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6280
process_backlog+0x37a/0x1580 net/core/dev.c:6631
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7695
napi_poll net/core/dev.c:7758 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7910
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
__do_softirq kernel/softirq.c:656 [inline]
invoke_softirq kernel/softirq.c:496 [inline]
__irq_exit_rcu+0xef/0x150 kernel/softirq.c:723
irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa3/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 68 85 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 23 3e 1e 00 fb f4 fc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffc90000197df0 EFLAGS: 00000242
RAX: 0000000000e45fcd RBX: ffff88801e6e0000 RCX: ffffffff8b8d4c75
RDX: 0000000000000000 RSI: ffffffff8de7b970 RDI: ffffffff8c1af620
RBP: 0000000000000001 R08: 0000000000000001 R09: ffffed10170a6795
R10: ffff8880b8533cab R11: 0000000000000000 R12: ffffed1003cdc000
R13: 0000000000000001 R14: ffffffff90d9b210 R15: 0000000000000000
arch_safe_halt arch/x86/include/asm/paravirt.h:73 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x35b/0x4b0 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312
common_startup_64+0x13e/0x148