rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=f91/1/0x4000000000000002 softirq=51621/51622 fqs=15 (detected by 1, t=10506 jiffies, g=72121, q=233) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 18771 Comm: syz.6.3848 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+0x12/0x30 kernel/rcu/update.c:280 Code: 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 b9 ec 0a 00 00 00 0f 94 c0 RSP: 0018:ffffc90000006fa0 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff8880b9035178 RCX: ffff88805be01dc0 RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000001 R08: dffffc0000000000 R09: ffffc90000007120 R10: fffff52000000e2b R11: 1ffff92000000e24 R12: dffffc0000000000 R13: ffffc90000007186 R14: ffffffff8bf23920 R15: dffffc0000000000 FS: 00007f988b8f46c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000005771d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: rcu_read_lock_held_common kernel/rcu/update.c:104 [inline] rcu_read_lock_held+0x6/0x40 kernel/rcu/update.c:309 perf_get_guest_cbs include/linux/perf_event.h:1274 [inline] perf_misc_flags+0x56/0x1b0 arch/x86/events/core.c:2961 perf_prepare_sample+0x132/0x1cb0 kernel/events/core.c:7608 __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: a7d13ca0e1e0ee00 RBX: 1ffff92000000ef4 RCX: a7d13ca0e1e0ee00 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 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:account_kernel_stack+0x209/0x340 kernel/fork.c:387 Code: 85 db 75 1c e8 c8 00 31 00 49 83 fd 38 75 1d eb 29 e8 bb 00 31 00 e8 16 6a 61 08 48 85 db 74 e4 e8 ac 00 31 00 fb 49 83 fd 38 <74> 0e e8 a0 00 31 00 49 83 c5 08 e9 dc fe ff ff e8 92 00 31 00 4c RSP: 0018:ffffc90002e8f280 EFLAGS: 00000293 RAX: ffffffff8146c374 RBX: 0000000000000200 RCX: ffff88805be01dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90002e8f388 R08: dffffc0000000000 R09: ffffed101720765a R10: ffffed101720765a R11: 1ffff11017207659 R12: 1ffff1100c744034 R13: 0000000000000000 R14: ffff888063a201a0 R15: 0000000000000000 release_task_stack kernel/fork.c:432 [inline] put_task_stack+0x8f/0x140 kernel/fork.c:444 finish_task_switch+0x26f/0x640 kernel/sched/core.c:4942 context_switch kernel/sched/core.c:5033 [inline] __schedule+0x11c0/0x43b0 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:84 [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+0x89/0x290 mm/kasan/generic.c:189 Code: 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 1c 01 00 00 44 89 cb 83 e3 07 0f 84 b5 00 00 00 41 80 39 00 4d RSP: 0018:ffffc90002e8f778 EFLAGS: 00000256 RAX: ffffffff81459b01 RBX: 0000000000000000 RCX: ffffffff81459b5b RDX: 0000000000000001 RSI: 0000000000000003 RDI: ffffffffa00023ca RBP: ffffc90002e8fb30 R08: dffffc0000000000 R09: fffffbfff400047a R10: fffffbfff400047a R11: 1ffffffff4000479 R12: ffffffff81459b5b R13: ffffc90001096069 R14: 0000000000000001 R15: dffffc0000000001 memcpy+0x3c/0x60 mm/kasan/shadow.c:66 do_jit arch/x86/net/bpf_jit_comp.c:1832 [inline] bpf_int_jit_compile+0x6fab/0xcc80 arch/x86/net/bpf_jit_comp.c:2431 bpf_prog_select_runtime+0x74f/0xaa0 kernel/bpf/core.c:1934 bpf_prog_load+0x106e/0x1550 kernel/bpf/syscall.c:2352 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4651 __do_sys_bpf kernel/bpf/syscall.c:4755 [inline] __se_sys_bpf kernel/bpf/syscall.c:4753 [inline] __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4753 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: 0033:0x7f988d68cbe9 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:00007f988b8f4038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141 RAX: ffffffffffffffda RBX: 00007f988d8b3fa0 RCX: 00007f988d68cbe9 RDX: 0000000000000090 RSI: 00002000000004c0 RDI: 0000000000000005 RBP: 00007f988d70fe19 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f988d8b4038 R14: 00007f988d8b3fa0 R15: 00007ffe06c5dab8 rcu: rcu_preempt kthread timer wakeup didn't happen for 10434 jiffies! g72121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=31308 rcu: rcu_preempt kthread starved for 10435 jiffies! g72121 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27712 pid: 15 ppid: 2 flags:0x00004000 Call Trace: 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 rcu: Stack dump where RCU GP kthread last ran: NMI backtrace for cpu 1 CPU: 1 PID: 4218 Comm: syz-executor Not tainted 5.15.189-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline] rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline] rcu_pending kernel/rcu/tree.c:3936 [inline] rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619 update_process_times+0x193/0x200 kernel/time/timer.c:1818 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473 __run_hrtimer kernel/time/hrtimer.c:1690 [inline] __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline] __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918 Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 5f da 49 00 44 38 e3 75 10 66 90 0f 00 2d 61 63 d4 08 fb f4 33 ff ff ff fb e9 2d ff ff ff e8 7f 25 74 08 89 f9 80 e1 07 38 RSP: 0018:ffffc900032ff8c0 EFLAGS: 00000246 RAX: 17849d161878c100 RBX: 0000000000000003 RCX: 17849d161878c100 RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340 RBP: ffffc900032ff970 R08: dffffc0000000000 R09: fffffbfff1ff6e32 R10: fffffbfff1ff6e32 R11: 1ffffffff1ff6e31 R12: 0000000000000003 R13: ffff8880b913b114 R14: dffffc0000000000 R15: 1ffff9200065ff18 pv_wait arch/x86/include/asm/paravirt.h:597 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline] do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115 spin_lock_bh include/linux/spinlock.h:368 [inline] lock_sock_nested+0x68/0x100 net/core/sock.c:3254 lock_sock include/net/sock.h:1694 [inline] tcp_sendmsg+0x1d/0x40 net/ipv4/tcp.c:1456 sock_sendmsg_nosec net/socket.c:704 [inline] __sock_sendmsg net/socket.c:716 [inline] sock_write_iter+0x29c/0x380 net/socket.c:1079 call_write_iter include/linux/fs.h:2172 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x712/0xd00 fs/read_write.c:594 ksys_write+0x14d/0x250 fs/read_write.c:647 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: 0033:0x7f5c590d7660 Code: 40 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 80 3d 01 af 1f 00 00 74 17 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 58 c3 0f 1f 80 00 00 00 00 48 83 ec 28 48 89 RSP: 002b:00007ffd50b659f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 000000002de54480 RCX: 00007f5c590d7660 RDX: 0000000000000290 RSI: 00007f5c54f49d70 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000007 R09: 00000000003ffde8 R10: 9067ca1d5568fa59 R11: 0000000000000202 R12: 0000000000000290 R13: 0000555562dcc8c0 R14: 00007ffd50b65ec0 R15: 00007f5c54f49d70