rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6723
rcu: (detected by 0, t=10503 jiffies, g=18841, q=1371 ncpus=2)
task:syz.3.341 state:R running task stack:26512 pid:6723 ppid:5787 flags:0x0000400e
Call Trace:
sched_show_task+0x481/0x5a0 kernel/sched/core.c:9179
rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:261 [inline]
print_other_cpu_stall+0xfa7/0x1340 kernel/rcu/tree_stall.h:637
check_cpu_stall kernel/rcu/tree_stall.h:809 [inline]
rcu_pending kernel/rcu/tree.c:3950 [inline]
rcu_sched_clock_irq+0x87c/0x1220 kernel/rcu/tree.c:2295
update_process_times+0x147/0x1b0 kernel/time/timer.c:2071
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x3a2/0x580 kernel/time/tick-sched.c:1492
__run_hrtimer kernel/time/hrtimer.c:1755 [inline]
__hrtimer_run_queues+0x4df/0xc40 kernel/time/hrtimer.c:1819
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1881
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:319 [inline]
RIP: 0010:handle_softirqs+0x1b0/0x820 kernel/softirq.c:566
Code: 89 64 24 2c 0f b7 db 48 c7 c7 a0 b1 a9 8a e8 47 19 1d 09 65 66 c7 05 1d 25 b2 7e 00 00 e8 88 74 3a 00 fb 49 c7 c6 c0 a0 a0 8c <89> 5c 24 34 b8 ff ff ff ff 0f bc 44 24 34 41 89 c5 41 ff c5 0f 84
RSP: 0018:ffffc90000007e40 EFLAGS: 00000286
RAX: 57d81ea03f1f3300 RBX: 0000000000000200 RCX: 57d81ea03f1f3300
RDX: dffffc0000000000 RSI: ffffffff8aaab940 RDI: ffffffff8afc7880
RBP: ffffc90000007f50 R08: ffffffff90da6537 R09: 1ffffffff21b4ca6
R10: dffffc0000000000 R11: fffffbfff21b4ca7 R12: 000000000000000a
R13: 0000000000000000 R14: ffffffff8ca0a0c0 R15: ffff8880269abc00
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0xa1/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
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 19 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900044bfc00 EFLAGS: 00000206
RAX: 57d81ea03f1f3300 RBX: 1ffff92000897f88 RCX: 57d81ea03f1f3300
RDX: dffffc0000000000 RSI: ffffffff8aaab940 RDI: ffffffff8afc7880
RBP: ffffc900044bfcf0 R08: ffffffff90da6537 R09: 1ffffffff21b4ca6
R10: dffffc0000000000 R11: fffffbfff21b4ca7 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd35418
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock+0x85/0xa0 include/linux/rcupdate.h:818
dput+0xe6/0x1e0 fs/dcache.c:911
__fput+0x5e5/0x970 fs/file_table.c:392
task_work_run+0x1ce/0x250 kernel/task_work.c:239
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop+0xe6/0x110 kernel/entry/common.c:177
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302
do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb6ee98e929
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:00007ffdb84dc308 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 00007fb6eebb7ba0 RCX: 00007fb6ee98e929
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007fb6eebb7ba0 R08: 000000000000fd84 R09: 0000000ab84dc5ff
R10: 00000000005eb97c R11: 0000000000000246 R12: 000000000002215f
R13: 00007fb6eebb6080 R14: ffffffffffffffff R15: 00007ffdb84dc420
rcu: rcu_preempt kthread starved for 5017 jiffies! g18841 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:26024 pid:17 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x14e2/0x4580 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x160/0x280 kernel/time/timer.c:2167
rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:1866
kthread+0x2fa/0x390 kernel/kthread.c:388
ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152
ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 6753 Comm: udevd Not tainted 6.6.98-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:245 [inline]
RIP: 0010:__sanitizer_cov_trace_switch+0x9f/0x120 kernel/kcov.c:350
Code: 4c 8b 05 54 0e 7e 7e 45 31 c9 eb 08 49 ff c1 4c 39 c8 74 77 4e 8b 54 ce 10 65 44 8b 1d 42 0e 7e 7e 41 81 e3 00 01 ff 00 74 13 <41> 81 fb 00 01 00 00 75 d9 41 83 b8 1c 16 00 00 00 74 cf 45 8b 98
RSP: 0018:ffffc900001f0470 EFLAGS: 00000206
RAX: 0000000000000020 RBX: 0000003916e98f87 RCX: 0000000000000005
RDX: ffffffff8188ab7d RSI: ffffffff8cd79a20 RDI: 0000000000000004
RBP: 0000000000000004 R08: ffff888029ab9e00 R09: 0000000000000014
R10: 0000000000000014 R11: 0000000000000100 R12: ffff88801c27b45c
R13: f800000000000000 R14: 000000000000044c R15: 000000000008e604
FS: 00007fda25599880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffdfcc89158 CR3: 00000000769b4000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
check_buffer+0x24d/0x950 kernel/trace/ring_buffer.c:3495
__rb_reserve_next+0x511/0xd50 kernel/trace/ring_buffer.c:3624
rb_reserve_next_event kernel/trace/ring_buffer.c:3759 [inline]
ring_buffer_lock_reserve+0xae1/0xed0 kernel/trace/ring_buffer.c:3818
__trace_buffer_lock_reserve kernel/trace/trace.c:992 [inline]
trace_event_buffer_lock_reserve+0x1d0/0x6e0 kernel/trace/trace.c:2902
trace_event_buffer_reserve+0x29b/0x3c0 kernel/trace/trace_events.c:661
do_trace_event_raw_event_bpf_trace_printk kernel/trace/bpf_trace.h:11 [inline]
trace_event_raw_event_bpf_trace_printk+0x101/0x210 kernel/trace/bpf_trace.h:11
trace_bpf_trace_printk+0x142/0x1a0 kernel/trace/bpf_trace.h:11
____bpf_trace_printk kernel/trace/bpf_trace.c:388 [inline]
bpf_trace_printk+0x11f/0x190 kernel/trace/bpf_trace.c:371
bpf_prog_0605f9f479290f07+0x37/0x3b
bpf_dispatcher_nop_func include/linux/bpf.h:1213 [inline]
__bpf_prog_run include/linux/filter.h:612 [inline]
bpf_prog_run include/linux/filter.h:619 [inline]
__bpf_trace_run kernel/trace/bpf_trace.c:2322 [inline]
bpf_trace_run1+0x1c9/0x3b0 kernel/trace/bpf_trace.c:2360
__bpf_trace_rcu_utilization+0xa2/0xe0 include/trace/events/rcu.h:27
trace_rcu_utilization+0x179/0x1a0 include/trace/events/rcu.h:27
rcu_core+0x1341/0x1720 kernel/rcu/tree.c:2475
handle_softirqs+0x280/0x820 kernel/softirq.c:578
__do_softirq kernel/softirq.c:612 [inline]
invoke_softirq kernel/softirq.c:452 [inline]
__irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661
irq_exit_rcu+0x9/0x20 kernel/softirq.c:673
instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline]
sysvec_irq_work+0xa1/0xc0 arch/x86/kernel/irq_work.c:17
asm_sysvec_irq_work+0x1a/0x20 arch/x86/include/asm/idtentry.h:723
RIP: 0010:rcu_read_unlock_special+0x88/0x4c0 kernel/rcu/tree_plugin.h:682
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 19 4e 93 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc900051d7440 EFLAGS: 00000206
RAX: 1924aa2db4437e00 RBX: 1ffff92000a3ae90 RCX: 1924aa2db4437e00
RDX: dffffc0000000000 RSI: ffffffff8aaab940 RDI: ffffffff8afc7880
RBP: ffffc900051d7540 R08: ffffffff90da65c7 R09: 1ffffffff21b4cb8
R10: dffffc0000000000 R11: fffffbfff21b4cb9 R12: 0000000000000000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffffffff8cd35418
__rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426
rcu_read_unlock include/linux/rcupdate.h:818 [inline]
d_alloc_parallel+0x119e/0x1480 fs/dcache.c:2733
__lookup_slow+0x117/0x3b0 fs/namei.c:1679
lookup_slow+0x53/0x70 fs/namei.c:1711
walk_component fs/namei.c:2002 [inline]
link_path_walk+0x970/0xe00 fs/namei.c:2329
path_openat+0x283/0x3190 fs/namei.c:3785
do_filp_open+0x1c5/0x3d0 fs/namei.c:3816
do_sys_openat2+0x12c/0x1c0 fs/open.c:1419
do_sys_open fs/open.c:1434 [inline]
__do_sys_openat fs/open.c:1450 [inline]
__se_sys_openat fs/open.c:1445 [inline]
__x64_sys_openat+0x139/0x160 fs/open.c:1445
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fda24ea7407
Code: 48 89 fa 4c 89 df e8 38 aa 00 00 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 1a 5b c3 0f 1f 84 00 00 00 00 00 48 8b 44 24 10 0f 05 <5b> c3 0f 1f 80 00 00 00 00 83 e2 39 83 fa 08 75 de e8 23 ff ff ff
RSP: 002b:00007ffdfcc89010 EFLAGS: 00000202 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fda25599880 RCX: 00007fda24ea7407
RDX: 0000000000080000 RSI: 00007ffdfcc89190 RDI: ffffffffffffff9c
RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 000055eb07db97f5
R13: 000055eb07db97f5 R14: 0000000000000001 R15: 000055eb07dd4140