rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=593/1/0x4000000000000002 softirq=8981/8981 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5282 (detected by 1, t=10506 jiffies, g=10685, q=1943) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 5282 Comm: syz.2.254 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:perf_tp_event_match kernel/events/core.c:10000 [inline] RIP: 0010:perf_tp_event+0x257/0xb50 kernel/events/core.c:10046 Code: 00 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 80 3c 08 00 74 08 4c 89 ff e8 a3 50 25 00 4d 8b 3f 4c 89 fe 48 83 e6 20 <31> ff e8 d2 eb e0 ff 49 83 e7 20 75 11 e8 e7 e7 e0 ff eb 43 e8 e0 RSP: 0018:ffffc9000395f800 EFLAGS: 00000046 RAX: 1ffff1100eb55a92 RBX: 1ffff11017206a35 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000395fa68 R08: dffffc0000000000 R09: ffffed1003bfb771 R10: ffffed1003bfb771 R11: 1ffff11003bfb770 R12: ffff8880b90351a8 R13: ffff888075aad390 R14: 0000000000000000 R15: 0000000000000000 FS: 00005555813d0500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2de79e CR3: 00000000502b0000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: 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:ffffc9000395fcc0 EFLAGS: 00000206 RAX: 412839f54856e400 RBX: 1ffff9200072bf9c RCX: 412839f54856e400 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffc9000395fd88 R08: dffffc0000000000 R09: fffffbfff1ff541a R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c120c60 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock+0x85/0x90 include/linux/rcupdate.h:772 dput+0xc0/0x1a0 fs/dcache.c:886 __fput+0x5ee/0x930 fs/file_table.c:319 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9185a84749 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:00007ffe9d31d1c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f9185cdcda0 RCX: 00007f9185a84749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f9185cdcda0 R08: 0000000000000208 R09: 0000001e9d31d4bf R10: 00007f9185cdccb0 R11: 0000000000000246 R12: 000000000001b1c2 R13: 00007f9185cdb180 R14: ffffffffffffffff R15: 00007ffe9d31d2e0 task:syz.2.254 state:R running task stack:26912 pid: 5282 ppid: 4186 flags:0x0000400c Call Trace: rcu: rcu_preempt kthread timer wakeup didn't happen for 10505 jiffies! g10685 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=6996 rcu: rcu_preempt kthread starved for 10506 jiffies! g10685 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:26688 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: 5282 Comm: syz.2.254 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_preemption_disabled+0x42/0x110 lib/smp_processor_id.c:55 Code: 65 8b 05 d9 1d 60 76 65 8b 0d 42 78 60 76 f7 c1 ff ff ff 7f 74 1f 65 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 <48> 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 RSP: 0018:ffffc9000395fad0 EFLAGS: 00000046 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 412839f54856e400 RDX: 0000000000000000 RSI: ffffffff8a59e7e0 RDI: ffffffff8a59e7a0 RBP: ffffc9000395fbc8 R08: dffffc0000000000 R09: fffffbfff1ad26b6 R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: 0000000000000000 R13: 0000000000000000 R14: ffff8880b9000000 R15: 0000000000000802 FS: 00005555813d0500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2de79e CR3: 00000000502b0000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: rcu_dynticks_curr_cpu_in_eqs kernel/rcu/tree.c:331 [inline] rcu_nmi_enter+0x2e/0xf0 kernel/rcu/tree.c:1010 rcu_irq_enter_irqson+0x8b/0x110 kernel/rcu/tree.c:1087 trace_irq_enable_rcuidle+0xc6/0x180 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:ffffc9000395fcc0 EFLAGS: 00000206 RAX: 412839f54856e400 RBX: 1ffff9200072bf9c RCX: 412839f54856e400 RDX: dffffc0000000000 RSI: ffffffff8a0b1be0 RDI: ffffffff8a59e800 RBP: ffffc9000395fd88 R08: dffffc0000000000 R09: fffffbfff1ff541a R10: fffffbfff1ff541a R11: 1ffffffff1ff5419 R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c120c60 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock+0x85/0x90 include/linux/rcupdate.h:772 dput+0xc0/0x1a0 fs/dcache.c:886 __fput+0x5ee/0x930 fs/file_table.c:319 task_work_run+0x125/0x1a0 kernel/task_work.c:188 tracehook_notify_resume include/linux/tracehook.h:189 [inline] exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f9185a84749 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:00007ffe9d31d1c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f9185cdcda0 RCX: 00007f9185a84749 RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003 RBP: 00007f9185cdcda0 R08: 0000000000000208 R09: 0000001e9d31d4bf R10: 00007f9185cdccb0 R11: 0000000000000246 R12: 000000000001b1c2 R13: 00007f9185cdb180 R14: ffffffffffffffff R15: 00007ffe9d31d2e0