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 1, t=10502 jiffies, g=8061, q=88)
task:udevd state:R running task stack:25824 pid: 3547 ppid: 1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780
irqentry_exit+0x63/0x70 kernel/entry/common.c:432
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock+0x2b/0x40 kernel/locking/spinlock.c:186
Code: 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ce 9b b1 f7 48 89 df e8 96 70 b2 f7 bf 01 00 00 00 e8 cc 94 a6 f7 65 8b 05 6d a4 57 76 <85> c0 74 02 5b c3 e8 1a af 55 f7 5b c3 0f 1f 84 00 00 00 00 00 55
RSP: 0018:ffffc90002d3f670 EFLAGS: 00000297
RAX: 0000000080000000 RBX: ffff8880766ef810 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000004 RDI: 00000000ffffffff
RBP: 0000006b636f6c62 R08: dffffc0000000000 R09: ffffed100ecddf03
R10: ffffed100ecddf03 R11: 1ffff1100ecddf02 R12: dffffc0000000000
R13: 00000000fffffffd R14: ffff8880766ef780 R15: 0000000000000000
spin_unlock include/linux/spinlock.h:403 [inline]
__d_lookup+0x5f3/0x760 fs/dcache.c:2446
lookup_fast+0xd7/0x710 fs/namei.c:1621
walk_component+0x81/0x460 fs/namei.c:1972
link_path_walk+0x662/0xd40 fs/namei.c:-1
path_openat+0x27d/0x2f30 fs/namei.c:3738
do_filp_open+0x1b3/0x3e0 fs/namei.c:3769
do_sys_openat2+0x142/0x4a0 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+0x135/0x160 fs/open.c:1280
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fa075468c3a
RSP: 002b:00007ffe5b63d798 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 000055ba03458c20 RCX: 00007fa075468c3a
RDX: 0000000000090800 RSI: 000055ba034033a0 RDI: 00000000ffffff9c
RBP: 000055ba034033a0 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000206 R12: 000055ba0340f760
R13: 00000000000000ff R14: 000055b9f6005be0 R15: 00007ffe5b63da20
rcu: rcu_preempt kthread starved for 10538 jiffies! g8061 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:28032 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 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: 4453 Comm: syz.0.51 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:arch_irqs_disabled_flags arch/x86/include/asm/irqflags.h:127 [inline]
RIP: 0010:check_preemption_disabled+0x59/0x110 lib/smp_processor_id.c:19
Code: 48 8b 0c 25 28 00 00 00 48 3b 4c 24 08 0f 85 c4 00 00 00 48 83 c4 10 5b 41 5e 41 5f 5d c3 48 c7 04 24 00 00 00 00 9c 8f 04 24 04 24 00 02 00 00 74 cc 65 4c 8b 3d 86 f2 60 76 41 f6 47 2f 04
RSP: 0018:ffffc900032efd28 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff888029ded940 RCX: 0000000080000000
RDX: 0000000000000000 RSI: ffffffff8a0b1fc0 RDI: ffffffff8a59a740
RBP: ffffc900032efe80 R08: dffffc0000000000 R09: fffffbfff1ad157e
R10: fffffbfff1ad157e R11: 1ffffffff1ad157d R12: 1ffff110053bdc14
R13: dffffc0000000000 R14: ffff888029dee42c R15: 1ffff9200065dfb8
FS: 00007f5b5b04d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffff0000 CR3: 000000006c890000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lockdep_recursion_inc kernel/locking/lockdep.c:431 [inline]
lock_release+0x156/0x870 kernel/locking/lockdep.c:5642
do_write_seqcount_end include/linux/seqlock.h:565 [inline]
vtime_user_exit+0x2dc/0x400 kernel/sched/cputime.c:732
__context_tracking_exit+0x4c/0x80 kernel/context_tracking.c:160
user_exit_irqoff include/linux/context_tracking.h:47 [inline]
__enter_from_user_mode kernel/entry/common.c:22 [inline]
syscall_enter_from_user_mode+0x56/0x70 kernel/entry/common.c:110
do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f5b5d181b19
Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25
RSP: 002b:00007f5b5b04cb40 EFLAGS: 00000246 ORIG_RAX: 000000000000000f
RAX: ffffffffffffffda RBX: 00007f5b5d40cfa8 RCX: 00007f5b5d181b19
RDX: 00007f5b5b04cb40 RSI: 00007f5b5b04cc70 RDI: 0000000000000011
RBP: 00007f5b5d40cfa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5b5d40cfac
R13: 0000000000000000 R14: 00007ffd58f9f290 R15: 00007ffd58f9f378