rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3637/1:b..l
(detected by 1, t=10502 jiffies, g=7917, q=92 ncpus=2)
task:udevd state:R running task stack:25184 pid:3637 ppid:1 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194
spin_unlock_irqrestore include/linux/spinlock.h:406 [inline]
__wake_up_common_lock kernel/sched/wait.c:140 [inline]
__wake_up_sync_key+0x11b/0x180 kernel/sched/wait.c:208
sock_def_readable+0x15b/0x280 net/core/sock.c:3308
__netlink_sendskb net/netlink/af_netlink.c:1264 [inline]
netlink_sendskb+0x97/0x130 net/netlink/af_netlink.c:1270
netlink_sendmsg+0x89e/0xbc0 net/netlink/af_netlink.c:1872
sock_sendmsg_nosec net/socket.c:718 [inline]
__sock_sendmsg net/socket.c:730 [inline]
____sys_sendmsg+0x59b/0x970 net/socket.c:2519
___sys_sendmsg+0x21c/0x290 net/socket.c:2573
__sys_sendmsg net/socket.c:2602 [inline]
__do_sys_sendmsg net/socket.c:2611 [inline]
__se_sys_sendmsg+0x19e/0x270 net/socket.c:2609
do_syscall_x64 arch/x86/entry/common.c:51 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fc3324a7407
RSP: 002b:00007ffc071ad480 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007fc332c71880 RCX: 00007fc3324a7407
RDX: 0000000000000000 RSI: 00007ffc071ad4e0 RDI: 0000000000000004
RBP: 000055fd42ee8f90 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00000000000000b2
R13: 000055fd42ec49e0 R14: 0000000000000000 R15: 0000000000000000
</TASK>
rcu: rcu_preempt kthread starved for 10528 jiffies! g7917 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:27432 pid:16 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5244 [inline]
__schedule+0x10ec/0x40b0 kernel/sched/core.c:6561
schedule+0xb9/0x180 kernel/sched/core.c:6637
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965
rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 PID: 10 Comm: mm_percpu_wq Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:finish_task_switch+0x26a/0x8f0 kernel/sched/core.c:5123
Code: 0f 84 3b 01 00 00 48 85 db 0f 85 5a 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 10 e0 c8 08 e8 cb b2 2e 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0
RSP: 0018:ffffc900000f7a38 EFLAGS: 00000282
RAX: e1cab035d5cb0800 RBX: 0000000000000000 RCX: e1cab035d5cb0800
RDX: dffffc0000000000 RSI: ffffffff8a8c0300 RDI: ffffffff8adefae0
RBP: ffffc900000f7a90 R08: dffffc0000000000 R09: ffffed10171e7551
R10: ffffed10171e7551 R11: 1ffff110171e7550 R12: ffff88813fec1dc0
R13: dffffc0000000000 R14: ffff888026ee9dc0 R15: ffff8880b8f3b550
FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000005cd89000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5247 [inline]
__schedule+0x10f4/0x40b0 kernel/sched/core.c:6561
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873
irqentry_exit+0x63/0x70 kernel/entry/common.c:439
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:wq_worker_running+0x42/0x190 kernel/workqueue.c:872
Code: 94 b1 2d 00 48 89 df e8 2c 41 02 00 49 89 c6 48 8d 58 70 49 89 dd 49 c1 ed 03 43 0f b6 44 25 00 84 c0 0f 85 e0 00 00 00 8b 2b <31> ff 89 ee e8 c5 b4 2d 00 85 ed 74 43 bf 01 00 00 00 e8 c7 95 04
RSP: 0018:ffffc900000f7db0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff888017618b70 RCX: ffff88813fec1dc0
RDX: 0000000000000000 RSI: 0000000000200000 RDI: 0000000000000000
RBP: 0000000000000000 R08: dffffc0000000000 R09: ffffed1027fd83b9
R10: ffffed1027fd83b9 R11: 1ffff11027fd83b8 R12: dffffc0000000000
R13: 1ffff11002ec316e R14: ffff888017618b00 R15: ffff888017618b30
rescuer_thread+0xe74/0xf90 kernel/workqueue.c:2602
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>