rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=9c1c/1/0x4000000000000000 softirq=38524/38525 fqs=3
rcu: (detected by 1, t=10502 jiffies, g=28629, q=561 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 5186 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:check_preemption_disabled+0x25/0xe0 lib/smp_processor_id.c:54
Code: 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d d5 91 3a 08 65 8b 05 ca 91 3a 08 a9 ff ff ff 7f 74 0f 48 83 c4 08 89 d8 5b 5d <41> 5c c3 cc cc cc cc 9c 58 f6 c4 02 74 ea 48 89 fd 65 48 8b 05 8a
RSP: 0018:ffffc90000007e18 EFLAGS: 00000082
RAX: 0000000000000000 RBX: ffff8880b8428540 RCX: ffffffff81aac8f6
RDX: ffff888020aa0000 RSI: ffffffff8bf2b380 RDI: ffffffff8bf2b3c0
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: ffff888020aa0b30 R12: ffff8880b8428440
R13: 0000000000000001 R14: ffff88807917c300 R15: 0000000000000001
FS: 00007f75aec04880(0000) GS:ffff8881248f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000206f2000 CR4: 00000000003526f0
Call Trace:
<IRQ>
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x12/0xc0 kernel/rcu/tree.c:751
trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline]
__run_hrtimer kernel/time/hrtimer.c:1780 [inline]
__hrtimer_run_queues+0x9bf/0xc40 kernel/time/hrtimer.c:1841
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x3c0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1056
</IRQ>
<TASK>
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:bpf_bprintf_prepare+0x3c1/0x13f0 kernel/bpf/helpers.c:853
Code: be e0 ff 31 ff 89 ee e8 3d b8 e0 ff 40 84 ed 0f 88 9a 01 00 00 e8 ef bd e0 ff 89 ee bf 25 00 00 00 41 8d 5d 01 e8 1f b8 e0 ff <40> 80 fd 25 0f 85 49 03 00 00 e8 d0 bd e0 ff 48 63 eb 4c 01 f5 48
RSP: 0018:ffffc90003d4f7f0 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000003 RCX: ffffffff81de2891
RDX: ffff888020aa0000 RSI: 0000000000000025 RDI: 0000000000000001
RBP: 0000000000000070 R08: 0000000000000001 R09: 0000000000000025
R10: 0000000000000070 R11: ffff888020aa0b30 R12: ffffc90003d4fa10
R13: 0000000000000002 R14: ffffc90003d4fa10 R15: dffffc0000000000
____bpf_trace_printk kernel/trace/bpf_trace.c:372 [inline]
bpf_trace_printk+0xda/0x190 kernel/trace/bpf_trace.c:362
bpf_prog_930ede9872f2967c+0x3e/0x44
bpf_dispatcher_nop_func include/linux/bpf.h:1378 [inline]
__bpf_prog_run include/linux/filter.h:723 [inline]
bpf_prog_run include/linux/filter.h:730 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2075 [inline]
bpf_trace_run2+0x239/0x5c0 kernel/trace/bpf_trace.c:2116
__bpf_trace_contention_begin+0xc9/0x110 include/trace/events/lock.h:95
__do_trace_contention_begin include/trace/events/lock.h:95 [inline]
trace_contention_begin+0xc1/0x110 include/trace/events/lock.h:95
__mutex_lock_common kernel/locking/mutex.c:616 [inline]
__mutex_lock+0x1b7/0x1ca0 kernel/locking/mutex.c:776
kernfs_open_file_mutex_lock fs/kernfs/file.c:56 [inline]
kernfs_unlink_open_file+0x6a/0x4b0 fs/kernfs/file.c:583
kernfs_fop_release+0xe9/0x1e0 fs/kernfs/file.c:783
__fput+0x402/0xb70 fs/file_table.c:468
fput_close_sync+0x118/0x260 fs/file_table.c:573
__do_sys_close fs/open.c:1573 [inline]
__se_sys_close fs/open.c:1558 [inline]
__x64_sys_close+0x8b/0x120 fs/open.c:1558
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f75ae515a67
Code: 44 00 00 48 83 ec 10 48 63 ff 45 31 c9 45 31 c0 6a 01 31 c9 e8 ca 19 f9 ff 48 83 c4 18 c3 0f 1f 44 00 00 b8 03 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 01 c3 48 8b 15 61 b3 0d 00 f7 d8 64 89 02 b8
RSP: 002b:00007ffc2d3bc168 EFLAGS: 00000297 ORIG_RAX: 0000000000000003
RAX: ffffffffffffffda RBX: 00005614c72465c0 RCX: 00007f75ae515a67
RDX: 00007f75ae5efea0 RSI: 00005614c7263a50 RDI: 000000000000000c
RBP: 00007f75ae5efff0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000297 R12: 0000000000000000
R13: 3d45505954564544 R14: 3d5845444e494649 R15: 3d454d414e564544
</TASK>
rcu: rcu_preempt kthread starved for 10496 jiffies! g28629 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:28064 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 8814 Comm: syz.6.623 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x15e0 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 35 5b 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 b6 05 00 00 8b 43 08 31
RSP: 0000:ffffc90004117720 EFLAGS: 00000246
RAX: 0000000000080000 RBX: ffff8880b84431e0 RCX: ffffc9000f0fe000
RDX: 0000000000080000 RSI: ffffffff81b28b3b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: dffffc0000000000
R13: ffffed101708863d R14: 0000000000000001 R15: 0000000000000000
FS: 00007ff92b3a96c0(0000) GS:ffff8881249f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000499ac000 CR4: 00000000003526f0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x2f0/0x12c0 arch/x86/mm/tlb.c:1472
dup_mmap+0xd04/0x20e0 mm/mmap.c:1866
dup_mm kernel/fork.c:1529 [inline]
copy_mm kernel/fork.c:1581 [inline]
copy_process+0x3b9f/0x7430 kernel/fork.c:2221
kernel_clone+0xfc/0x910 kernel/fork.c:2651
__do_sys_clone+0xce/0x120 kernel/fork.c:2792
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff92a58f749
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:00007ff92b3a8fe8 EFLAGS: 00000206 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ff92a7e5fa0 RCX: 00007ff92a58f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000100000
RBP: 00007ff92a613f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007ff92a7e6038 R14: 00007ff92a7e5fa0 R15: 00007ffd270d9d28
</TASK>