rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=637/1/0x4000000000000000 softirq=19706/19706 fqs=0 (detected by 1, t=10506 jiffies, g=26565, q=904) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8057 Comm: syz.2.934 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 50 d3 f1 0b 48 89 de 5b e9 57 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 RSP: 0018:ffffc90000007720 EFLAGS: 00000046 RAX: ffffffff8196ed72 RBX: 0000000000000000 RCX: ffff88807e8d8000 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff8880b90351c8 R08: dffffc0000000000 R09: fffffbfff1ad33a6 R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 0000000000000001 R13: ffff888079458000 R14: ffffc90000007800 R15: ffff888079458000 FS: 0000555588bf5500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32063fff CR3: 000000008170d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: perf_swevent_event+0xc8/0x530 kernel/events/core.c:9614 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 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:674 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 ed 11 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:ffffc90000007c60 EFLAGS: 00000206 RAX: 956e73eaf2f4d400 RBX: 1ffff92000000f90 RCX: 956e73eaf2f4d400 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580 RBP: ffffc90000007d28 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] rebalance_domains+0xa51/0xb80 kernel/sched/fair.c:10660 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:__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 de 0d cb 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 f6 95 9e f7 65 8b 05 87 93 4f 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900031af8a0 EFLAGS: 00000206 RAX: 956e73eaf2f4d400 RBX: 0000000000000a06 RCX: 956e73eaf2f4d400 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001 RBP: ffffc900031af930 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: dffffc0000000000 R13: ffff88804bf6b358 R14: ffffffff96290390 R15: 1ffff92000635f14 __debug_object_init+0x217/0xa40 lib/debugobjects.c:633 hrtimer_init_sleeper_on_stack+0x1f/0x30 kernel/time/hrtimer.c:435 futex_setup_timer kernel/futex/core.c:463 [inline] futex_wait+0x140/0x5c0 kernel/futex/core.c:2952 do_futex+0xd1c/0x1240 kernel/futex/core.c:3982 __do_sys_futex kernel/futex/core.c:4059 [inline] __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040 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: 0033:0x7f0bdf8ba749 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:00007ffdaca05ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 0000000000033823 RCX: 00007f0bdf8ba749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0bdfb10fac RBP: 0000000000000032 R08: 00399df63a4759f0 R09: 00000014aca05dcf R10: 00007ffdaca05bd0 R11: 0000000000000246 R12: 00007f0bdfb10fac R13: 00007ffdaca05bd0 R14: 0000000000033855 R15: 00007ffdaca05bf0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g26565 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=14635 rcu: rcu_preempt kthread starved for 10506 jiffies! g26565 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:27200 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8057 Comm: syz.2.934 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x60 kernel/kcov.c:202 Code: 66 2e 0f 1f 84 00 00 00 00 00 53 48 89 fb e8 17 00 00 00 48 8b 3d 50 d3 f1 0b 48 89 de 5b e9 57 9e 43 00 00 00 cc cc 00 00 cc <48> 8b 04 24 65 48 8b 0d a4 a3 8a 7e 65 8b 15 a5 a3 8a 7e 81 e2 00 RSP: 0018:ffffc90000007598 EFLAGS: 00000086 RAX: ffffffff81966a68 RBX: ffff88813fe46578 RCX: ffff88807e8d8000 RDX: 0000000000000100 RSI: 00000000ffffffe4 RDI: 0000000000000000 RBP: ffffc900000076b8 R08: dffffc0000000000 R09: fffffbfff1ad33a6 R10: fffffbfff1ad33a6 R11: 1ffffffff1ad33a5 R12: 00000000ffffffe4 R13: 1ffff92000000eb8 R14: ffffc900000075e0 R15: ffffc90000007800 FS: 0000555588bf5500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b32063fff CR3: 000000008170d000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __perf_event_output kernel/events/core.c:7805 [inline] perf_event_output_forward+0x172/0x280 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_swevent_overflow kernel/events/core.c:9591 [inline] perf_swevent_event+0x4ad/0x530 kernel/events/core.c:9629 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 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:674 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 ed 11 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:ffffc90000007c60 EFLAGS: 00000206 RAX: 956e73eaf2f4d400 RBX: 1ffff92000000f90 RCX: 956e73eaf2f4d400 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: ffffffff8a59e580 RBP: ffffc90000007d28 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: ffffffff8c120c00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] rebalance_domains+0xa51/0xb80 kernel/sched/fair.c:10660 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:__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 de 0d cb 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 f6 95 9e f7 65 8b 05 87 93 4f 76 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900031af8a0 EFLAGS: 00000206 RAX: 956e73eaf2f4d400 RBX: 0000000000000a06 RCX: 956e73eaf2f4d400 RDX: dffffc0000000000 RSI: ffffffff8a0b1c60 RDI: 0000000000000001 RBP: ffffc900031af930 R08: dffffc0000000000 R09: ffffed1017207662 R10: ffffed1017207662 R11: 1ffff11017207661 R12: dffffc0000000000 R13: ffff88804bf6b358 R14: ffffffff96290390 R15: 1ffff92000635f14 __debug_object_init+0x217/0xa40 lib/debugobjects.c:633 hrtimer_init_sleeper_on_stack+0x1f/0x30 kernel/time/hrtimer.c:435 futex_setup_timer kernel/futex/core.c:463 [inline] futex_wait+0x140/0x5c0 kernel/futex/core.c:2952 do_futex+0xd1c/0x1240 kernel/futex/core.c:3982 __do_sys_futex kernel/futex/core.c:4059 [inline] __se_sys_futex+0x3a3/0x430 kernel/futex/core.c:4040 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: 0033:0x7f0bdf8ba749 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:00007ffdaca05ad8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 0000000000033823 RCX: 00007f0bdf8ba749 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0bdfb10fac RBP: 0000000000000032 R08: 00399df63a4759f0 R09: 00000014aca05dcf R10: 00007ffdaca05bd0 R11: 0000000000000246 R12: 00007f0bdfb10fac R13: 00007ffdaca05bd0 R14: 0000000000033855 R15: 00007ffdaca05bf0