rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3547/1:b..l
(detected by 0, t=10502 jiffies, g=8609, q=114)
task:udevd state:R running task stack:23168 pid: 3547 ppid: 1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6780
irqentry_exit+0x53/0x80 kernel/entry/common.c:432
asm_sysvec_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:681
RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627
Code: 2b 00 74 08 4c 89 f7 e8 4c ad 67 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25
RSP: 0018:ffffc90002dcf540 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920005b9eb4 RCX: 1ffff920005b9e54
RDX: dffffc0000000000 RSI: ffffffff8aab3e00 RDI: ffffffff8af9fc80
RBP: ffffc90002dcf6a0 R08: dffffc0000000000 R09: fffffbfff2132219
R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920005b9eb0
R13: dffffc0000000000 R14: ffffc90002dcf5a0 R15: 0000000000000246
rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:312
rcu_read_lock include/linux/rcupdate.h:739 [inline]
get_obj_cgroup_from_current+0xd3/0x2f0 mm/memcontrol.c:2924
memcg_slab_pre_alloc_hook mm/slab.h:283 [inline]
slab_pre_alloc_hook+0x87/0xc0 mm/slab.h:497
slab_alloc_node mm/slub.c:3134 [inline]
slab_alloc mm/slub.c:3228 [inline]
kmem_cache_alloc+0x3f/0x280 mm/slub.c:3233
__d_alloc+0x2a/0x700 fs/dcache.c:1749
d_alloc fs/dcache.c:1828 [inline]
d_alloc_parallel+0xca/0x1390 fs/dcache.c:2582
lookup_open fs/namei.c:3387 [inline]
open_last_lookups fs/namei.c:3532 [inline]
path_openat+0x96f/0x2f20 fs/namei.c:3739
do_filp_open+0x21c/0x460 fs/namei.c:3769
do_sys_openat2+0x13b/0x4f0 fs/open.c:1253
do_sys_open fs/open.c:1269 [inline]
__do_sys_openat fs/open.c:1285 [inline]
__se_sys_openat fs/open.c:1280 [inline]
__x64_sys_openat+0x243/0x290 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fecd4d499a4
RSP: 002b:00007fff00c75620 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055705d09b040 RCX: 00007fecd4d499a4
RDX: 0000000000080141 RSI: 000055705d07e0d8 RDI: 00000000ffffff9c
RBP: 000055705d07e0d8 R08: 00000000ffffffff R09: 0000000000000000
R10: 00000000000001a4 R11: 0000000000000246 R12: 0000000000080141
R13: ffffffffffffffff R14: 00000000ffffffff R15: 00000000ffffffff
rcu: rcu_preempt kthread starved for 10534 jiffies! g8609 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:26752 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x12c4/0x45b0 kernel/sched/core.c:6376
schedule+0x11b/0x1f0 kernel/sched/core.c:6459
schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
kthread+0x3f6/0x4f0 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:
NMI backtrace for cpu 0
CPU: 0 PID: 4640 Comm: syz.0.112 Not tainted 5.15.180-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3932 [inline]
rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
update_process_times+0x196/0x200 kernel/time/timer.c:1818
tick_sched_handle kernel/time/tick-sched.c:254 [inline]
tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
__run_hrtimer kernel/time/hrtimer.c:1690 [inline]
__hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1754
hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1816
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
__sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x37/0x240 kernel/entry/common.c:114
Code: 49 89 fe 48 8b 7c 24 30 e8 46 f6 ff ff e9 8d 01 00 00 e9 91 01 00 00 e8 07 f4 46 f7 e8 f2 f1 46 f7 fb 65 4c 8b 3d 49 45 c2 75 <49> 8b 5f 08 f6 c3 3f 0f 84 ce 00 00 00 f6 c3 20 74 17 4c 89 f7 e8
RSP: 0018:ffffc900011ffef8 EFLAGS: 00000282
RAX: 8455f86c344acf00 RBX: ffffc900011fff30 RCX: ffffffff96a97f03
RDX: dffffc0000000000 RSI: ffffffff8aab2b60 RDI: ffffffff8af9fc80
RBP: ffffc900011fff48 R08: ffffffff81871c90 R09: fffffbfff1c154de
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: 00000000000000ca R14: ffffc900011fff58 R15: ffff88802acd0000
do_syscall_64+0x1e/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa3f25eb169
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:00007fa3f04320e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007fa3f2813088 RCX: 00007fa3f25eb169
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fa3f2813088
RBP: 00007fa3f2813080 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa3f281308c
R13: 0000000000000000 R14: 00007ffd09b0d0e0 R15: 00007ffd09b0d1c8