rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5139/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=59493, q=330 ncpus=2)
task:udevd state:R running task stack:23144 pid:5139 ppid:1 flags:0x00004002
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
preempt_schedule_irq+0xbf/0x150 kernel/sched/core.c:7010
irqentry_exit+0x67/0x70 kernel/entry/common.c:438
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:seqcount_lockdep_reader_access+0x199/0x1d0 include/linux/seqlock.h:105
Code: ff 4d 85 ed 75 16 e8 f6 87 94 ff eb 15 e8 ef 87 94 ff e8 ca c0 93 08 4d 85 ed 74 ea e8 e0 87 94 ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 43 c7 44 27 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc900032f7980 EFLAGS: 00000293
RAX: ffffffff81f29a20 RBX: 0000000000000000 RCX: ffff88807e089e00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900032f7a28 R08: ffffffff8e8b14ef R09: 1ffffffff1d1629d
R10: dffffc0000000000 R11: fffffbfff1d1629e R12: dffffc0000000000
R13: 0000000000000200 R14: ffffffff81f29fce R15: 1ffff9200065ef30
set_root+0x15e/0x3a0 fs/namei.c:948
nd_jump_root+0x2a7/0x410 fs/namei.c:969
path_init+0x3e5/0x1200 fs/namei.c:2401
path_lookupat+0x27/0x440 fs/namei.c:2481
filename_lookup+0x228/0x560 fs/namei.c:2520
user_path_at_empty+0x42/0x60 fs/namei.c:2917
do_readlinkat+0xdd/0x490 fs/stat.c:494
__do_sys_readlink fs/stat.c:527 [inline]
__se_sys_readlink fs/stat.c:524 [inline]
__x64_sys_readlink+0x7f/0x90 fs/stat.c:524
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fec863153a7
RSP: 002b:00007ffd4f10be18 EFLAGS: 00000202 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffd4f10c660 RCX: 00007fec863153a7
RDX: 0000000000000400 RSI: 00007ffd4f10c220 RDI: 00007ffd4f10be20
RBP: 0000000000000200 R08: 000055d0d69d3c29 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000202 R12: 00007ffd4f10be20
R13: 00007ffd4f10c220 R14: 0000000000000000 R15: 00007ffd4f10cb70
</TASK>
rcu: rcu_preempt kthread starved for 5251 jiffies! g59493 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:26920 pid:17 ppid:2 flags:0x00004000
Call Trace:
<TASK>
context_switch kernel/sched/core.c:5381 [inline]
__schedule+0x1553/0x45a0 kernel/sched/core.c:6700
schedule+0xbd/0x170 kernel/sched/core.c:6774
schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x313/0x1590 kernel/rcu/tree.c:1667
rcu_gp_kthread+0x9d/0x3b0 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
</TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x10 arch/x86/kernel/paravirt.c:148
Code: 29 21 02 c3 cc cc cc cc cc cc cc f3 0f 1e fa 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 f3 0f 1e fa 66 90 0f 00 2d 83 e3 41 00 fb f4 <c3> 66 0f 1f 00 55 41 57 41 56 41 54 53 50 8b 2f eb 2e 41 89 de 80
RSP: 0018:ffffffff8ce07d80 EFLAGS: 000002c6
RAX: e4daa1b098828400 RBX: ffffffff8162a8f1 RCX: e4daa1b098828400
RDX: 0000000000000001 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60
RBP: ffffffff8ce07eb8 R08: ffff8880b8e36b2b R09: 1ffff110171c6d65
R10: dffffc0000000000 R11: ffffed10171c6d66 R12: 1ffffffff19c0fbc
R13: dffffc0000000000 R14: 1ffffffff19d2688 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b34c1cff8 CR3: 000000005a658000 CR4: 00000000003506f0
Call Trace:
<TASK>
arch_safe_halt arch/x86/include/asm/paravirt.h:108 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:753
default_idle_call+0x6c/0xa0 kernel/sched/idle.c:97
cpuidle_idle_call kernel/sched/idle.c:178 [inline]
do_idle+0x221/0x590 kernel/sched/idle.c:302
cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:401
rest_init+0x2e2/0x300 init/main.c:744
arch_call_rest_init+0xe/0x10 init/main.c:841
start_kernel+0x459/0x4e0 init/main.c:1086
x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:555
x86_64_start_kernel+0x60/0x60 arch/x86/kernel/head64.c:536
secondary_startup_64_no_verify+0x179/0x17b
</TASK>