rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4430
(detected by 1, t=10502 jiffies, g=7561, q=606)
task:syz.4.57 state:R running task stack:26128 pid: 4430 ppid: 4197 flags:0x00004008
Call Trace:
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g7561 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=4247
rcu: rcu_preempt kthread starved for 10502 jiffies! g7561 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:27952 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9b/0x370 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: 4430 Comm: syz.4.57 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:hlock_class kernel/locking/lockdep.c:197 [inline]
RIP: 0010:check_wait_context kernel/locking/lockdep.c:4711 [inline]
RIP: 0010:__lock_acquire+0x92d/0x7d10 kernel/locking/lockdep.c:4962
Code: 89 c6 41 81 e6 ff 1f 00 00 c1 e8 03 25 f8 03 00 00 48 8d b8 c0 50 1d 90 be 08 00 00 00 e8 db 35 61 00 4c 0f a3 35 a3 31 c0 0e <73> 1a 4b 8d 04 76 c1 e0 06 4c 8d b0 80 cf b5 8f 49 b8 00 00 00 00
RSP: 0018:ffffc900031df0e0 EFLAGS: 00000057
RAX: 0000000000000001 RBX: 0000000000000002 RCX: ffffffff815d1f15
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901d50c0
RBP: ffffc900031df330 R08: ffffffff901d50c7 R09: 1ffffffff203aa18
R10: dffffc0000000000 R11: fffffbfff203aa19 R12: ffff88801e41c6e0
R13: 0000000000000002 R14: 0000000000000015 R15: ffff88801e41c6e0
FS: 000055557f607500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c2c5ee0 CR3: 00000000605e0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire+0x19e/0x400 kernel/locking/lockdep.c:5623
rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:313
rcu_read_lock include/linux/rcupdate.h:740 [inline]
__task_pid_nr_ns+0x21/0x420 kernel/pid.c:497
perf_event_pid_type kernel/events/core.c:1446 [inline]
perf_event_tid kernel/events/core.c:1460 [inline]
__perf_event_header__init_id+0x20b/0x500 kernel/events/core.c:7106
perf_prepare_sample+0x158/0x1cd0 kernel/events/core.c:7624
__perf_event_output kernel/events/core.c:7802 [inline]
perf_event_output_forward+0x185/0x2e0 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+0x383/0xbf0 kernel/events/core.c:10047
perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
perf_trace_preemptirq_template+0x2aa/0x360 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+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674
Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 32 e1 9c 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08
RSP: 0018:ffffc900031dfcc0 EFLAGS: 00000206
RAX: cdd1698219faae00 RBX: 1ffff9200063bf9c RCX: cdd1698219faae00
RDX: dffffc0000000000 RSI: ffffffff8a2b2800 RDI: ffffffff8a79fe40
RBP: ffffc900031dfd88 R08: ffffffff901d50cf R09: 1ffffffff203aa19
R10: dffffc0000000000 R11: fffffbfff203aa1a R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8c323060
__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: 0033:0x7f27640c1dd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fffa0e7d198 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007f276433cda0 RCX: 00007f27640c1dd9
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f276433cda0 R08: 00007f276433b128 R09: 0000000000000000
R10: 00000000003ffcd0 R11: 0000000000000246 R12: 0000000000013073
R13: 00007f276433b09c R14: 0000000000012e46 R15: 00007fffa0e7d2a0