rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (10499 ticks this GP) idle=f0dc/1/0x4000000000000000 softirq=11054/11056 fqs=32
rcu: (t=10500 jiffies g=10813 q=917 ncpus=2)
rcu: rcu_preempt kthread starved for 10363 jiffies! g10813 f0x0 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:27848 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x15ae/0x4660 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 13 Comm: kworker/u4:1 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xd85/0x1190 kernel/smp.c:855
Code: 45 8b 34 24 44 89 f6 83 e6 01 31 ff e8 34 f1 0a 00 41 83 e6 01 49 be 00 00 00 00 00 fc ff df 75 07 e8 6f ed 0a 00 eb 38 f3 90 <42> 0f b6 04 33 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 53 ed
RSP: 0018:ffffc90000127780 EFLAGS: 00000293
RAX: ffffffff817bf7fd RBX: 1ffff110171c87a9 RCX: ffff88801be50000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90000127900 R08: ffffffff911bc507 R09: 1ffffffff22378a0
R10: dffffc0000000000 R11: fffffbfff22378a1 R12: ffff8880b8e43d48
R13: ffff8880b8f3d3c0 R14: dffffc0000000000 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f360c0e8492 CR3: 000000000cf32000 CR4: 00000000003506e0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x31e/0x980 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xa8/0x260 mm/kfence/core.c:847
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2730
worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2811
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
</TASK>
CPU: 0 PID: 5880 Comm: syz.3.4 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x27/0x60 kernel/kcov.c:216
Code: cc cc cc f3 0f 1e fa 48 8b 04 24 65 48 8b 0d e0 d2 7c 7e 65 8b 15 e1 d2 7c 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 <83> b9 1c 16 00 00 00 74 2c 8b 91 f8 15 00 00 83 fa 02 75 21 48 8b
RSP: 0018:ffffc900000074b0 EFLAGS: 00000246
RAX: ffffffff813b23f7 RBX: ffffc90000007640 RCX: ffff88802bd63c00
RDX: 0000000000000100 RSI: ffffffff81f36c30 RDI: ffffc90000007588
RBP: ffffc90000007610 R08: ffffc90000007650 R09: 0000000000000015
R10: 0000000000000004 R11: 0000000000000100 R12: ffffffff81f36c30
R13: ffffc90000007588 R14: ffffffff81758be0 R15: dffffc0000000000
FS: 00007fa7d192a6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000100000000 CR3: 000000001db70000 CR4: 00000000003506f0
Call Trace:
<IRQ>
unwind_next_frame+0x27/0x2990 arch/x86/kernel/unwind_orc.c:469
arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:46 [inline]
kasan_set_track+0x4e/0x70 mm/kasan/common.c:53
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329
kasan_slab_alloc include/linux/kasan.h:188 [inline]
slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:767
slab_alloc_node mm/slub.c:3495 [inline]
kmem_cache_alloc_node+0x1af/0x310 mm/slub.c:3540
__alloc_skb+0x103/0x2c0 net/core/skbuff.c:643
alloc_skb include/linux/skbuff.h:1316 [inline]
ndisc_alloc_skb+0xa6/0x450 net/ipv6/ndisc.c:423
ndisc_send_rs+0x27d/0x690 net/ipv6/ndisc.c:707
addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4029
call_timer_fn+0x189/0x540 kernel/time/timer.c:1701
expire_timers kernel/time/timer.c:1752 [inline]
__run_timers+0x570/0x810 kernel/time/timer.c:2023
run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036
handle_softirqs+0x27d/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:preempt_schedule_irq+0xba/0x150 kernel/sched/core.c:7010
Code: 00 00 43 c6 44 37 04 f8 74 0b 0f 0b 48 f7 03 08 00 00 00 74 6f bf 01 00 00 00 e8 01 48 d0 f6 e8 3c 34 01 f7 fb bf 01 00 00 00 <e8> 31 b4 ff ff 43 c6 44 37 08 00 48 c7 44 24 40 00 00 00 00 9c 8f
RSP: 0018:ffffc90004b47cc0 EFLAGS: 00000282
RAX: 97422cfe89e96900 RBX: 0000000000000000 RCX: 97422cfe89e96900
RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: 0000000000000001
RBP: ffffc90004b47d70 R08: ffffffff8e8ae5ef R09: 1ffffffff1d15cbd
R10: dffffc0000000000 R11: fffffbfff1d15cbe R12: 0000000000000000
R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000968f98
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__fget_files_rcu fs/file.c:848 [inline]
RIP: 0010:__fget_files+0x19d/0x460 fs/file.c:892
Code: f7 e8 67 f2 e8 ff 49 8b 06 48 85 c0 0f 84 96 02 00 00 4c 89 74 24 28 48 89 04 24 4c 8d 70 50 4c 89 f0 48 c1 e8 03 0f b6 04 28 <84> c0 0f 85 6d 01 00 00 41 8b 2e 44 89 e6 21 ee 31 ff e8 6c 81 90
RSP: 0018:ffffc90004b47e30 EFLAGS: 00000a02
RAX: 0000000000000000 RBX: 1ffff1100f6cde03 RCX: 0000000000000003
RDX: ffff88802bd63c00 RSI: 0000000000000100 RDI: 0000000000000003
RBP: dffffc0000000000 R08: dffffc0000000000 R09: 1ffffffff22378a0
R10: dffffc0000000000 R11: fffffbfff22378a1 R12: 0000000000004000
R13: ffffffff81f66608 R14: ffff88802fbf4a50 R15: 0000000000000003
__fget fs/file.c:900 [inline]
__fget_light fs/file.c:1000 [inline]
__fdget+0x173/0x210 fs/file.c:1008
fdget include/linux/file.h:64 [inline]
__do_sys_ioctl fs/ioctl.c:859 [inline]
__se_sys_ioctl+0x20/0x170 fs/ioctl.c:857
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fa7d099ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fa7d192a028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fa7d0c15fa0 RCX: 00007fa7d099ce59
RDX: ffffffffffffffff RSI: 0000000040042408 RDI: 0000000000000003
RBP: 00007fa7d0a32e6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa7d0c16038 R14: 00007fa7d0c15fa0 R15: 00007ffdae907178
</TASK>