rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=71c4/1/0x4000000000000000 softirq=27504/27504 fqs=0
rcu: 	(detected by 1, t=10502 jiffies, g=27269, q=464 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 10921 Comm: syz.0.2438 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__lock_release kernel/locking/lockdep.c:5459 [inline]
RIP: 0010:lock_release+0x2ec/0x8b0 kernel/locking/lockdep.c:5774
Code: e0 48 c1 e8 03 42 80 3c 28 00 4c 8b 74 24 10 74 0e 4c 89 e7 48 89 d3 e8 c2 4e 75 00 48 89 da 49 8b 1c 24 49 81 c6 d0 0a 00 00 <4c> 89 f0 48 c1 e8 03 42 80 3c 28 00 74 0e 4c 89 f7 49 89 d4 e8 3b
RSP: 0018:ffffc90000006e20 EFLAGS: 00000082
RAX: 1ffff1100bc6a53a RBX: 9d4fca835d337a35 RCX: 0000000000000001
RDX: 0000000000000006 RSI: ffffffff8cd2fba0 RDI: ffff88805e3529d0
RBP: ffffc90000006f30 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d
R10: dffffc0000000000 R11: fffffbfff1c9509e R12: ffff88805e3529d0
R13: dffffc0000000000 R14: ffff88805e3528d0 R15: 1ffff92000000dd0
FS:  00007f20dbe7e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 0000000063ddd000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __perf_output_begin kernel/events/ring_buffer.c:264 [inline]
 perf_output_begin_forward+0x95b/0xa20 kernel/events/ring_buffer.c:273
 __perf_event_output kernel/events/core.c:7960 [inline]
 perf_event_output_forward+0x22b/0x3a0 kernel/events/core.c:7978
 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9703
 perf_swevent_overflow kernel/events/core.c:9779 [inline]
 perf_swevent_event+0x2f5/0x5c0 kernel/events/core.c:-1
 perf_tp_event+0x4f9/0x13a0 kernel/events/core.c:10329
 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10253
 perf_trace_preemptirq_template+0x281/0x340 include/trace/events/preemptirq.h:14
 trace_irq_enable+0xbf/0xe0 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
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 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 941df4e64dcda300 RBX: 1ffff92000000ef8 RCX: 941df4e64dcda300
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc90000007878 R08: ffffffff90da35af R09: 1ffffffff21b46b5
R10: dffffc0000000000 R11: fffffbfff21b46b6 R12: ffffffff8cd35400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:818 [inline]
 __ip_queue_xmit+0x1115/0x1a00 net/ipv4/ip_output.c:536
 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422
 tcp_delack_timer_handler+0x2ad/0x440 net/ipv4/tcp_timer.c:330
 tcp_delack_timer+0x18c/0x2e0 net/ipv4/tcp_timer.c:353
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 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:generic_exec_single+0x476/0x4f0 kernel/smp.c:418
Code: 75 11 e8 3d e6 0a 00 48 85 db 75 16 e8 33 e6 0a 00 eb 15 e8 2c e6 0a 00 e8 27 69 f2 08 48 85 db 74 ea e8 1d e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c
RSP: 0018:ffffc90003677a00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88805e351e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003677ad0 R08: ffffffff90da362f R09: 1ffffffff21b46c5
R10: dffffc0000000000 R11: fffffbfff21b46c6 R12: 1ffff920006cef44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920006cef65
 smp_call_function_single+0x352/0x580 kernel/smp.c:647
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948
 __do_sys_perf_event_open kernel/events/core.c:12900 [inline]
 __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12552
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f20daf8ebe9
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:00007f20dbe7e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f20db1b5fa0 RCX: 00007f20daf8ebe9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007f20db011e19 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f20db1b6038 R14: 00007f20db1b5fa0 R15: 00007ffca9e20ee8
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g27269 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=0 timer-softirq=11715
rcu: rcu_preempt kthread starved for 10502 jiffies! g27269 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:27080 pid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5381 [inline]
 __schedule+0x14d2/0x44d0 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: 10921 Comm: syz.0.2438 Not tainted 6.6.101-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:rcu_read_unlock_special+0x25/0x4c0 kernel/rcu/tree_plugin.h:627
Code: eb 84 0f 1f 00 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec c0 00 00 00 65 48 8b 04 25 28 00 00 00 <48> 89 84 24 a0 00 00 00 49 bd 00 00 00 00 00 fc ff df 48 c7 44 24
RSP: 0018:ffffc90000006f60 EFLAGS: 00000086
RAX: 941df4e64dcda300 RBX: ffff88805e35223c RCX: ffff88805e351e00
RDX: 0000000000000100 RSI: ffffffff8afc6760 RDI: ffff88805e351e00
RBP: ffffc90000007060 R08: ffffffff8e4a84ef R09: 1ffffffff1c9509d
R10: dffffc0000000000 R11: fffffbfff1c9509e R12: 1ffff1100bc6a447
R13: ffffc900000070e0 R14: ffff88805e352240 R15: dffffc0000000000
FS:  00007f20dbe7e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000140 CR3: 0000000063ddd000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:818 [inline]
 __perf_event_output kernel/events/core.c:7969 [inline]
 perf_event_output_forward+0x2e6/0x3a0 kernel/events/core.c:7978
 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9703
 perf_swevent_overflow kernel/events/core.c:9779 [inline]
 perf_swevent_event+0x2f5/0x5c0 kernel/events/core.c:-1
 perf_tp_event+0x4f9/0x13a0 kernel/events/core.c:10329
 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10253
 perf_trace_preemptirq_template+0x281/0x340 include/trace/events/preemptirq.h:14
 trace_irq_enable+0xbf/0xe0 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56
 asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
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 a9 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: 941df4e64dcda300 RBX: 1ffff92000000ef8 RCX: 941df4e64dcda300
RDX: dffffc0000000000 RSI: ffffffff8aaaba40 RDI: ffffffff8afc6780
RBP: ffffc90000007878 R08: ffffffff90da35af R09: 1ffffffff21b46b5
R10: dffffc0000000000 R11: fffffbfff21b46b6 R12: ffffffff8cd35400
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
 rcu_read_unlock include/linux/rcupdate.h:818 [inline]
 __ip_queue_xmit+0x1115/0x1a00 net/ipv4/ip_output.c:536
 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422
 tcp_delack_timer_handler+0x2ad/0x440 net/ipv4/tcp_timer.c:330
 tcp_delack_timer+0x18c/0x2e0 net/ipv4/tcp_timer.c:353
 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1700
 expire_timers kernel/time/timer.c:1751 [inline]
 __run_timers+0x52d/0x7d0 kernel/time/timer.c:2022
 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2035
 handle_softirqs+0x280/0x820 kernel/softirq.c:578
 __do_softirq kernel/softirq.c:612 [inline]
 invoke_softirq kernel/softirq.c:452 [inline]
 __irq_exit_rcu+0xc7/0x190 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:generic_exec_single+0x476/0x4f0 kernel/smp.c:418
Code: 75 11 e8 3d e6 0a 00 48 85 db 75 16 e8 33 e6 0a 00 eb 15 e8 2c e6 0a 00 e8 27 69 f2 08 48 85 db 74 ea e8 1d e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c
RSP: 0018:ffffc90003677a00 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff88805e351e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003677ad0 R08: ffffffff90da362f R09: 1ffffffff21b46c5
R10: dffffc0000000000 R11: fffffbfff21b46c6 R12: 1ffff920006cef44
R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff920006cef65
 smp_call_function_single+0x352/0x580 kernel/smp.c:647
 task_function_call kernel/events/core.c:120 [inline]
 perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948
 __do_sys_perf_event_open kernel/events/core.c:12900 [inline]
 __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12552
 do_syscall_x64 arch/x86/entry/common.c:51 [inline]
 do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f20daf8ebe9
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:00007f20dbe7e038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f20db1b5fa0 RCX: 00007f20daf8ebe9
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007f20db011e19 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f20db1b6038 R14: 00007f20db1b5fa0 R15: 00007ffca9e20ee8
 </TASK>