rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=029/1/0x4000000000000002 softirq=7185/7185 fqs=0 
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P4430/1:b..l
	(detected by 1, t=10502 jiffies, g=8573, q=326)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4480 Comm: syz.4.43 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280
Code: 60 14 0b 8a 48 c7 c6 e0 38 0b 8a e8 d1 34 f5 ff 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d 8b 3c c1 03 00 <74> 1d 83 3d 02 6f c1 03 00 74 14 65 48 8b 0d 74 3c 5a 76 31 c0 83
RSP: 0018:ffffc90000006f88 EFLAGS: 00000002
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff8880273d5940
RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900000070d0 R08: dffffc0000000000 R09: fffffbfff1ff6e19
R10: fffffbfff1ff6e19 R11: 1ffffffff1ff6e18 R12: 1ffff92000000e04
R13: 0000000000000008 R14: ffffc90000007120 R15: ffffc90000007340
FS:  00007f18142506c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5116dfad0 CR3: 0000000073f55000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 rcu_read_lock_held_common kernel/rcu/update.c:104 [inline]
 rcu_read_lock_held+0x6/0x40 kernel/rcu/update.c:309
 __perf_output_begin kernel/events/ring_buffer.c:170 [inline]
 perf_output_begin_forward+0x1a6/0xa30 kernel/events/ring_buffer.c:271
 __perf_event_output kernel/events/core.c:7790 [inline]
 perf_event_output_forward+0x15c/0x280 kernel/events/core.c:7808
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9501
 perf_swevent_overflow kernel/events/core.c:9577 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9615
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10033
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10007
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:671
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 7d 16 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 35fb713dd5350400 RBX: 1ffff92000000ef4 RCX: 35fb713dd5350400
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340
RBP: ffffc90000007860 R08: dffffc0000000000 R09: fffffbfff1ff6e32
R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: ffffffff8c120800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 __ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533
 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
 tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
 tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 2e 47 cc f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> f6 d4 9f f7 65 8b 05 97 d4 50 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90004b37ca0 EFLAGS: 00000206
RAX: 35fb713dd5350400 RBX: 0000000000000a02 RCX: 35fb713dd5350400
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001
RBP: ffffc90004b37d20 R08: dffffc0000000000 R09: ffffed101720765a
R10: ffffed101720765a R11: 1ffff11017207659 R12: dffffc0000000000
R13: ffff8880b9040280 R14: ffff8880b9040288 R15: 1ffff92000966f94
 find_get_context+0x327/0x950 kernel/events/core.c:4802
 __do_sys_perf_event_open kernel/events/core.c:12537 [inline]
 __se_sys_perf_event_open+0x8c3/0x1b80 kernel/events/core.c:12373
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1814be0be9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1814250038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f1814e07fa0 RCX: 00007f1814be0be9
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0
RBP: 00007f1814c63e19 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1814e08038 R14: 00007f1814e07fa0 R15: 00007ffff54a0988
 </TASK>
task:kworker/u4:8    state:R  running task     stack:25600 pid: 4430 ppid:     2 flags:0x00004000
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
 irqentry_exit+0x63/0x70 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:85 [inline]
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:102 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x7b/0x290 mm/kasan/generic.c:189
Code: 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce 49 83 fe 10 7f 26 4d 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41 80 39 00 <0f> 85 c1 01 00 00 49 ff c1 48 ff c3 75 ee e9 1c 01 00 00 44 89 cb
RSP: 0018:ffffc900049b7a80 EFLAGS: 00000246
RAX: 0000000000000001 RBX: ffffffffffffffff RCX: ffffffff815bf63b
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d696ea8
RBP: ffffc900049b7bc0 R08: dffffc0000000000 R09: fffffbfff1ad2dd5
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: ffffffff8c11c360
R13: 1ffff92000936f60 R14: 0000000000000001 R15: dffffc0000000001
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 cpu_online include/linux/cpumask.h:895 [inline]
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xbb/0x3f0 kernel/locking/lockdep.c:5594
 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312
 rcu_read_lock include/linux/rcupdate.h:739 [inline]
 batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline]
 batadv_nc_worker+0xc9/0x5c0 net/batman-adv/network-coding.c:723
 process_one_work+0x863/0x1000 kernel/workqueue.c:2310
 worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g8573 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=3655
rcu: rcu_preempt kthread starved for 10502 jiffies! g8573 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:27584 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5030 [inline]
 __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
 schedule+0x11b/0x1e0 kernel/sched/core.c:6459
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </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: 4480 Comm: syz.4.43 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:226 [inline]
RIP: 0010:__sanitizer_cov_trace_const_cmp8+0x4/0x80 kernel/kcov.c:300
Code: 77 22 89 ff 89 f6 4a c7 44 02 08 05 00 00 00 4a 89 7c 02 10 4a 89 74 02 18 4a 89 44 02 20 48 ff c1 48 89 0a c3 90 48 8b 04 24 <65> 48 8b 0d b4 a7 8a 7e 65 8b 15 b5 a7 8a 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc90000006fd8 EFLAGS: 00000046
RAX: ffffffff8196470f RBX: ffffc90000007180 RCX: ffff8880273d5940
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900000070d0 R08: dffffc0000000000 R09: ffffc90000007120
R10: fffff52000000e2b R11: 1ffff92000000e24 R12: dffffc0000000000
R13: ffffc90000007186 R14: 0000000000000000 R15: ffffc90000007340
FS:  00007f18142506c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd5116dfad0 CR3: 0000000073f55000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 perf_prepare_sample+0x7af/0x1cb0 kernel/events/core.c:7663
 __perf_event_output kernel/events/core.c:7788 [inline]
 perf_event_output_forward+0x146/0x280 kernel/events/core.c:7808
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9501
 perf_swevent_overflow kernel/events/core.c:9577 [inline]
 perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9615
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10033
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10007
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:671
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 7d 16 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 35fb713dd5350400 RBX: 1ffff92000000ef4 RCX: 35fb713dd5350400
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340
RBP: ffffc90000007860 R08: dffffc0000000000 R09: fffffbfff1ff6e32
R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: ffffffff8c120800
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 __ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533
 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
 tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
 tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa5/0x100 kernel/locking/spinlock.c:194
Code: 74 05 e8 2e 47 cc f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> f6 d4 9f f7 65 8b 05 97 d4 50 76 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90004b37ca0 EFLAGS: 00000206
RAX: 35fb713dd5350400 RBX: 0000000000000a02 RCX: 35fb713dd5350400
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: 0000000000000001
RBP: ffffc90004b37d20 R08: dffffc0000000000 R09: ffffed101720765a
R10: ffffed101720765a R11: 1ffff11017207659 R12: dffffc0000000000
R13: ffff8880b9040280 R14: ffff8880b9040288 R15: 1ffff92000966f94
 find_get_context+0x327/0x950 kernel/events/core.c:4802
 __do_sys_perf_event_open kernel/events/core.c:12537 [inline]
 __se_sys_perf_event_open+0x8c3/0x1b80 kernel/events/core.c:12373
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f1814be0be9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f1814250038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f1814e07fa0 RCX: 00007f1814be0be9
RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0
RBP: 00007f1814c63e19 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1814e08038 R14: 00007f1814e07fa0 R15: 00007ffff54a0988
 </TASK>