rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=0314/1/0x4000000000000000 softirq=44478/44480 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5974/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=34761, q=256 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5935 Comm: udevd Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_test_and_set_bit arch/x86/include/asm/bitops.h:137 [inline]
RIP: 0010:test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:72 [inline]
RIP: 0010:__netif_schedule+0x9c/0x2c0 net/core/dev.c:3379
Code: f3 f3 41 c6 44 0d 0b f3 e8 61 ee 74 f8 48 8d bb 58 01 00 00 be 08 00 00 00 e8 60 5a d8 f8 31 f6 f0 48 0f ba ab 58 01 00 00 00 <41> 0f 93 c6 40 0f 92 c6 bf 02 00 00 00 e8 32 f1 74 f8 45 84 f6 75
RSP: 0018:ffffc90000a08b80 EFLAGS: 00000047
RAX: ffffffff894b5201 RBX: ffff88805b15e000 RCX: ffffffff894b5250
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88805b15e158
RBP: ffffc90000a08c60 R08: ffff88805b15e15f R09: 1ffff1100b62bc2b
R10: dffffc0000000000 R11: ffffed100b62bc2c R12: ffff88805b15e360
R13: 1ffff92000141174 R14: 184a4c3e26930e05 R15: ffff88805b3ff000
FS: 00007fb896770880(0000) GS:ffff888125d59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f43d3e8bc18 CR3: 0000000028926000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
advance_sched+0xa9a/0xc90 net/sched/sch_taprio.c:986
__run_hrtimer kernel/time/hrtimer.c:1761 [inline]
__hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:debug_smp_processor_id+0x0/0x20 lib/smp_processor_id.c:59
Code: c7 c0 b0 1f 8e 4c 89 f6 e8 6d 78 91 f9 e9 66 ff ff ff cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 c7 c7 a0 8f e2 8b 48 c7 c6 e0 8f e2 8b eb 1c 66 66
RSP: 0018:ffffc90003067270 EFLAGS: 00000282
RAX: 0000000000000001 RBX: ffffffff823789cb RCX: ffff888025d99e00
RDX: 0000000000000000 RSI: ffffffff8db6a54c RDI: ffffffff8be29000
RBP: dffffc0000000000 R08: 0000000000000000 R09: ffffffff81728a45
R10: ffffc900030673b8 R11: ffffffff81ace110 R12: 1ffff9200060ce6d
R13: ffffc900030673a0 R14: ffffc90003067368 R15: ffffffff81728a45
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:745
rcu_read_lock include/linux/rcupdate.h:842 [inline]
class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
unwind_next_frame+0xd4/0x2390 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:47 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
unpoison_slab_object mm/kasan/common.c:319 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
kasan_slab_alloc include/linux/kasan.h:250 [inline]
slab_post_alloc_hook mm/slub.c:4147 [inline]
slab_alloc_node mm/slub.c:4196 [inline]
kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4215
__d_alloc+0x31/0x6f0 fs/dcache.c:1690
d_alloc fs/dcache.c:1769 [inline]
d_alloc_parallel+0xe0/0x14e0 fs/dcache.c:2533
lookup_open fs/namei.c:3630 [inline]
open_last_lookups fs/namei.c:3807 [inline]
path_openat+0xa3b/0x3830 fs/namei.c:4043
do_filp_open+0x1fa/0x410 fs/namei.c:4073
do_sys_openat2+0x121/0x1c0 fs/open.c:1437
do_sys_open fs/open.c:1452 [inline]
__do_sys_openat fs/open.c:1468 [inline]
__se_sys_openat fs/open.c:1463 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1463
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb896115c3a
Code: 41 89 f2 48 89 54 24 e0 41 83 e2 40 75 2a 89 f0 f7 d0 a9 00 00 41 00 74 1f 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 77 2e c3 0f 1f 44 00 00 48 8d 44 24 08 c7 44 24
RSP: 002b:00007ffd2d4b0a08 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007ffd2d4b0a40 RCX: 00007fb896115c3a
RDX: 0000000000090800 RSI: 00007ffd2d4b0e40 RDI: 00000000ffffff9c
RBP: 0000000000000007 R08: 000055d710b9c1f0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 000055d710bac2f0
R13: 00007ffd2d4b1640 R14: 00007ffd2d4b1240 R15: 00007ffd2d4b0e40
task:udevd state:R running task stack:22952 pid:5974 tgid:5974 ppid:5205 task_flags:0x400140 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965
preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989
preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock+0x190/0x1f0 kernel/sched/wait.c:108
sock_def_readable+0x1fb/0x550 net/core/sock.c:3544
unix_dgram_sendmsg+0xe44/0x17c0 net/unix/af_unix.c:2237
sock_sendmsg_nosec net/socket.c:712 [inline]
__sock_sendmsg+0x219/0x270 net/socket.c:727
sock_write_iter+0x258/0x330 net/socket.c:1131
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x548/0xa90 fs/read_write.c:686
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb8960a7407
RSP: 002b:00007ffd2d4b2390 EFLAGS: 00000202 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fb896770880 RCX: 00007fb8960a7407
RDX: 0000000000000000 RSI: 00007ffd2d4b2437 RDI: 000000000000000a
RBP: 000000000000000a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007fb8967706e8
R13: 0000000000000000 R14: 0000000000000000 R15: 000055d710ba7800
rcu: rcu_preempt kthread starved for 10506 jiffies! g34761 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27128 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5396 [inline]
__schedule+0x16f5/0x4d00 kernel/sched/core.c:6785
__schedule_loop kernel/sched/core.c:6863 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6878
schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054
rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256
kthread+0x711/0x8a0 kernel/kthread.c:464
ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 10198 Comm: syz.1.981 Not tainted 6.15.0-rc7-next-20250522-syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0xe69/0x11c0 kernel/smp.c:885
Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 70 75 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 1b 71 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 00 71 0b
RSP: 0018:ffffc90003747980 EFLAGS: 00000293
RAX: ffffffff81b4cfa0 RBX: ffff8880b863cb00 RCX: ffff88802cab3c00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003747ae0 R08: ffffffff8fa124f7 R09: 1ffffffff1f4249e
R10: dffffc0000000000 R11: fffffbfff1f4249f R12: 1ffff110170e8285
R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b8741428
FS: 00005555915ba500(0000) GS:ffff888125c59000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000003c80 CR3: 0000000032162000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2660 [inline]
smp_text_poke_batch_finish+0x5e0/0x1100 arch/x86/kernel/alternative.c:2870
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1b0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
tracepoint_remove_func kernel/tracepoint.c:370 [inline]
tracepoint_probe_unregister+0x80e/0x9b0 kernel/tracepoint.c:504
bpf_raw_tp_link_release+0x43/0x70 kernel/bpf/syscall.c:3635
bpf_link_free+0xed/0x330 kernel/bpf/syscall.c:3157
bpf_link_put_direct kernel/bpf/syscall.c:3200 [inline]
bpf_link_release+0x6b/0x80 kernel/bpf/syscall.c:3207
__fput+0x44c/0xa70 fs/file_table.c:467
task_work_run+0x1d4/0x260 kernel/task_work.c:227
resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
exit_to_user_mode_loop+0xec/0x110 kernel/entry/common.c:114
exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f79c658e969
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:00007ffd8561d5c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4
RAX: 0000000000000000 RBX: 0000000000098d67 RCX: 00007f79c658e969
RDX: 0000000000000000 RSI: 000000000000001e RDI: 0000000000000003
RBP: 00007f79c67b7ba0 R08: 0000000000000001 R09: 000000048561d8bf
R10: 00007f79c6400000 R11: 0000000000000246 R12: 00007f79c67b5fac
R13: 00007f79c67b5fa0 R14: ffffffffffffffff R15: 00007ffd8561d6e0