rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (10499 ticks this GP) idle=3124/1/0x4000000000000000 softirq=11904/22168 fqs=0
rcu: 	(t=10500 jiffies g=8989 q=65 ncpus=2)
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g8989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=4736
rcu: rcu_preempt kthread starved for 10500 jiffies! g8989 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27496 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14e2/0x4580 kernel/sched/core.c:6700
 schedule+0xbd/0x170 kernel/sched/core.c:6774
 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
 rcu_gp_kthread+0x99/0x380 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 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5866 Comm: kworker/0:5 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:__lock_acquire+0xfb8/0x7c80 kernel/locking/lockdep.c:-1
Code: 40 e8 0c be 75 00 eb bb 44 89 e0 25 ff 1f 00 00 41 c1 ec 03 41 81 e4 00 60 00 00 41 09 c4 4c 89 fe 48 c1 ee 20 89 f0 c1 c0 04 <41> 29 f4 44 31 e0 44 01 fe 41 29 c7 89 c1 c1 c1 06 44 31 f9 01 f0
RSP: 0018:ffffc900000077a0 EFLAGS: 00000003
RAX: 00000000be9ba323 RBX: 000000000000806b RCX: ffffffff81671ba0
RDX: 0000000000000000 RSI: 000000003be9ba32 RDI: ffffffff90da2520
RBP: ffffc900000079e8 R08: dffffc0000000000 R09: 1ffffffff21b44a4
R10: dffffc0000000000 R11: fffffbfff21b44a5 R12: 0000000000000000
R13: ffff88802e4e1e00 R14: ffff88802e4e28e0 R15: 3be9ba32c8301548
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bf5ffff CR3: 000000005f8ce000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 lock_acquire+0x197/0x410 kernel/locking/lockdep.c:5754
 debug_objects_fill_pool+0x92/0x6b0 lib/debugobjects.c:615
 debug_object_activate+0x36/0x4b0 lib/debugobjects.c:705
 debug_hrtimer_activate kernel/time/hrtimer.c:450 [inline]
 debug_activate kernel/time/hrtimer.c:505 [inline]
 enqueue_hrtimer+0x30/0x370 kernel/time/hrtimer.c:1113
 __run_hrtimer kernel/time/hrtimer.c:1772 [inline]
 __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/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:__zone_watermark_ok+0x32f/0x3f0 mm/page_alloc.c:-1
Code: 8b 14 24 e9 66 fe ff ff 44 89 fe 48 c7 c7 40 57 e1 8c e8 14 3f 80 02 48 b9 00 00 00 00 00 fc ff df 48 8b 14 24 e9 8e fe ff ff <31> c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 b0 01 eb ed 41
RSP: 0018:ffffc900033873b8 EFLAGS: 00000297
RAX: 1ffff11027fff5c8 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88813fffae00 RSI: 0000000000000002 RDI: ffff88813fffb490
RBP: ffff88813fffae40 R08: ffff88813fffb497 R09: 1ffff11027fff692
R10: dffffc0000000000 R11: ffffed1027fff693 R12: 0000000000000004
R13: 0000000000000005 R14: ffff88813fffae30 R15: 0000000000000000
 zone_watermark_fast+0x162/0x230 mm/page_alloc.c:2966
 get_page_from_freelist+0x35e/0x19f0 mm/page_alloc.c:3142
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 kmem_cache_alloc_node+0x1ea/0x330 mm/slub.c:3530
 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
 alloc_skb include/linux/skbuff.h:1284 [inline]
 ndisc_alloc_skb+0xa6/0x450 net/ipv6/ndisc.c:423
 ndisc_ns_create+0x213/0x640 net/ipv6/ndisc.c:626
 ndisc_send_ns+0xaf/0x150 net/ipv6/ndisc.c:668
 addrconf_dad_work+0xa25/0x14e0 net/ipv6/addrconf.c:4247
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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>
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 5866 Comm: kworker/0:5 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: ipv6_addrconf addrconf_dad_work
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp4+0x1f/0x90 kernel/kcov.c:313
Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 15 10 20 7e 7e 65 8b 0d 11 20 7e 7e 81 e1 00 01 ff 00 74 11 <81> f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 8a f8 15 00
RSP: 0018:ffffc90000007d00 EFLAGS: 00000006
RAX: ffffffff8175ec09 RBX: ffff88807b545340 RCX: 0000000000010000
RDX: ffff88802e4e1e00 RSI: 0000000000000001 RDI: 0000000000000020
RBP: 0000000000000010 R08: ffffffff8e4a7cef R09: 1ffffffff1c94f9d
R10: dffffc0000000000 R11: fffffbfff1c94f9e R12: dffffc0000000000
R13: 1ffff110171c5748 R14: ffff8880b8e2ba40 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2bf5ffff CR3: 000000005f8ce000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 enqueue_hrtimer+0x129/0x370 kernel/time/hrtimer.c:1116
 __run_hrtimer kernel/time/hrtimer.c:1772 [inline]
 __hrtimer_run_queues+0x637/0xc40 kernel/time/hrtimer.c:1819
 hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
 __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
 sysvec_apic_timer_interrupt+0x9f/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:__zone_watermark_ok+0x32f/0x3f0 mm/page_alloc.c:-1
Code: 8b 14 24 e9 66 fe ff ff 44 89 fe 48 c7 c7 40 57 e1 8c e8 14 3f 80 02 48 b9 00 00 00 00 00 fc ff df 48 8b 14 24 e9 8e fe ff ff <31> c0 48 83 c4 20 5b 41 5c 41 5d 41 5e 41 5f 5d c3 b0 01 eb ed 41
RSP: 0018:ffffc900033873b8 EFLAGS: 00000297
RAX: 1ffff11027fff5c8 RBX: 0000000000000000 RCX: dffffc0000000000
RDX: ffff88813fffae00 RSI: 0000000000000002 RDI: ffff88813fffb490
RBP: ffff88813fffae40 R08: ffff88813fffb497 R09: 1ffff11027fff692
R10: dffffc0000000000 R11: ffffed1027fff693 R12: 0000000000000004
R13: 0000000000000005 R14: ffff88813fffae30 R15: 0000000000000000
 zone_watermark_fast+0x162/0x230 mm/page_alloc.c:2966
 get_page_from_freelist+0x35e/0x19f0 mm/page_alloc.c:3142
 __alloc_pages+0x1e3/0x460 mm/page_alloc.c:4457
 alloc_slab_page+0x5d/0x170 mm/slub.c:1876
 allocate_slab mm/slub.c:2023 [inline]
 new_slab+0x87/0x2e0 mm/slub.c:2076
 ___slab_alloc+0xc6d/0x12f0 mm/slub.c:3230
 __slab_alloc mm/slub.c:3329 [inline]
 __slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc_node mm/slub.c:3475 [inline]
 kmem_cache_alloc_node+0x1ea/0x330 mm/slub.c:3530
 __alloc_skb+0x108/0x2c0 net/core/skbuff.c:640
 alloc_skb include/linux/skbuff.h:1284 [inline]
 ndisc_alloc_skb+0xa6/0x450 net/ipv6/ndisc.c:423
 ndisc_ns_create+0x213/0x640 net/ipv6/ndisc.c:626
 ndisc_send_ns+0xaf/0x150 net/ipv6/ndisc.c:668
 addrconf_dad_work+0xa25/0x14e0 net/ipv6/addrconf.c:4247
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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: 1 PID: 3495 Comm: kworker/u4:8 Not tainted 6.6.99-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:212
Code: 00 0f 0b 0f 1f 80 00 00 00 00 f3 0f 1e fa 53 48 89 fb e8 13 00 00 00 48 8b 3d ec e8 c4 0c 48 89 de 5b e9 f3 74 56 00 cc cc cc <f3> 0f 1e fa 48 8b 04 24 65 48 8b 0d c0 23 7e 7e 65 8b 15 c1 23 7e
RSP: 0018:ffffc9000cb47778 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 1ffff110171c87d9 RCX: ffff88802e4e3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000cb47900 R08: ffffffff90da2527 R09: 1ffffffff21b44a4
R10: dffffc0000000000 R11: fffffbfff21b44a5 R12: ffff8880b8e43ec8
R13: dffffc0000000000 R14: ffff8880b8f3d588 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f94c4e5b000 CR3: 000000000cb30000 CR4: 00000000003506e0
Call Trace:
 <TASK>
 csd_lock_wait kernel/smp.c:311 [inline]
 smp_call_function_many_cond+0xdf7/0x1130 kernel/smp.c:855
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1023
 on_each_cpu include/linux/smp.h:71 [inline]
 text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
 text_poke_bp_batch+0x318/0x930 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_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:237
 static_key_disable+0x1a/0x20 kernel/jump_label.c:245
 toggle_allocation_gate+0x1b0/0x250 mm/kfence/core.c:836
 process_one_work kernel/workqueue.c:2634 [inline]
 process_scheduled_works+0xa45/0x15b0 kernel/workqueue.c:2711
 worker_thread+0xa55/0xfc0 kernel/workqueue.c:2792
 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>