rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3562/1:b..l
(detected by 1, t=10502 jiffies, g=11929, q=454)
task:udevd state:R running task stack:25088 pid: 3562 ppid: 1 flags:0x00004002
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799
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:debug_lockdep_rcu_enabled+0x25/0x30 kernel/rcu/update.c:281
Code: 00 00 cc cc 00 31 c0 83 3d 2b 9c c0 03 00 74 1d 83 3d a2 ce c0 03 00 74 14 65 48 8b 0d 94 7b 59 76 31 c0 83 b9 ec 0a 00 00 00 <0f> 94 c0 c3 00 00 cc cc 00 00 cc 41 56 53 89 fb e8 16 0a 00 00 41
RSP: 0018:ffffc90002e6f7a0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: ffff88807a39c000 RCX: ffff88807bd90000
RDX: 0000000000000000 RSI: ffffffff8a0b28c0 RDI: ffffffff8a59a240
RBP: ffffc90002e6f8d0 R08: dffffc0000000000 R09: fffffbfff1ff7619
R10: fffffbfff1ff7619 R11: 1ffffffff1ff7618 R12: dffffc0000000000
R13: 1ffff920005cdf63 R14: 0000000000000000 R15: 0000000000200000
rcu_read_lock include/linux/rcupdate.h:740 [inline]
dput+0x3a/0x1a0 fs/dcache.c:879
step_into+0x31d/0xd00 fs/namei.c:1815
link_path_walk+0x662/0xd40 fs/namei.c:-1
path_lookupat+0x9d/0x440 fs/namei.c:2454
filename_lookup+0x1e2/0x4f0 fs/namei.c:2484
user_path_at_empty+0x40/0x190 fs/namei.c:2883
user_path_at include/linux/namei.h:57 [inline]
vfs_statx+0x102/0x4d0 fs/stat.c:221
vfs_fstatat fs/stat.c:243 [inline]
__do_sys_newfstatat fs/stat.c:411 [inline]
__se_sys_newfstatat fs/stat.c:405 [inline]
__x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
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: 0033:0x7f1311db2b0a
RSP: 002b:00007ffdfad05148 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffdfad055e0 RCX: 00007f1311db2b0a
RDX: 00007ffdfad05150 RSI: 00007ffdfad055e0 RDI: 00000000ffffff9c
RBP: 000055868a6bd910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffdfad051e0
R13: 0000558680b09100 R14: 000055868a6c7a70 R15: 00007ffdfad05c00
rcu: rcu_preempt kthread starved for 10533 jiffies! g11929 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:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
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: 4542 Comm: syz.0.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:ktime_get+0x24c/0x270 kernel/time/timekeeping.c:835
Code: 66 ff ff ff e8 c5 c9 0f 00 48 c7 c7 c0 e9 12 8c 4c 89 f6 48 89 da e8 73 b5 92 02 e9 79 ff ff ff e8 a9 c9 0f 00 89 d9 49 d3 ee <4c> 03 34 24 4c 89 f0 48 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f 5d c3
RSP: 0018:ffffc90004fc7ac0 EFLAGS: 00000006
RAX: ffffffff81680137 RBX: 0000000000000018 RCX: 0000000000000018
RDX: 0000000000000000 RSI: 0000000000000018 RDI: 0000000000000040
RBP: 000000000000d900 R08: dffffc0000000000 R09: fffffbfff1ad31e6
R10: fffffbfff1ad31e6 R11: 1ffffffff1ad31e5 R12: fffffffffe1c2c5b
R13: 000000973b02dfff R14: 0000000007205888 R15: 000001fb63109b96
FS: 000055555b347500(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000001eaca000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
common_hrtimer_rearm+0x5d/0x110 kernel/time/posix-timers.c:303
posixtimer_rearm+0x131/0x340 kernel/time/posix-timers.c:329
dequeue_signal+0x174/0x440 kernel/signal.c:696
get_signal+0x6fe/0x12c0 kernel/signal.c:2781
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fb23f92aba9
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:00007ffedceab6f8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fb23fb71fa0 RCX: 00007fb23f92aba9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007fb23f9ade19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fb23fb71fa0 R14: 00007fb23fb71fa0 R15: 0000000000000004
sched: RT throttling activated