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=12909, q=72)
task:udevd state:R running task stack:25008 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_common+0x82/0xd0 kernel/sched/core.c:6552
preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6577
preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
__raw_spin_unlock include/linux/spinlock_api_smp.h:152 [inline]
_raw_spin_unlock+0x36/0x40 kernel/locking/spinlock.c:186
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
lookup_last fs/namei.c:2431 [inline]
path_lookupat+0x169/0x440 fs/namei.c:2455
filename_lookup+0x1e2/0x4f0 fs/namei.c:2484
user_path_at_empty+0x40/0x190 fs/namei.c:2883
do_readlinkat+0xd4/0x480 fs/stat.c:442
__do_sys_readlink fs/stat.c:475 [inline]
__se_sys_readlink fs/stat.c:472 [inline]
__x64_sys_readlink+0x7b/0x90 fs/stat.c:472
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: 0033:0x7f2db20db3a7
RSP: 002b:00007ffd6645ca48 EFLAGS: 00000246 ORIG_RAX: 0000000000000059
RAX: ffffffffffffffda RBX: 00007ffd6645cf20 RCX: 00007f2db20db3a7
RDX: 0000000000000400 RSI: 00007ffd6645ca50 RDI: 00007ffd6645cf20
RBP: 00007ffd6645ca50 R08: 000055a4633c8144 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000400
R13: 00000000000000ff R14: 000055a452a9fbe0 R15: 00007ffd6645da00
rcu: rcu_preempt kthread starved for 10526 jiffies! g12909 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: 5284 Comm: syz.1.34 Not tainted 5.15.185-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:101 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:128 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:159 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x62/0x290 mm/kasan/generic.c:189
Code: ff df 49 89 fb 49 c1 eb 03 49 b8 00 00 00 00 00 fc ff df 4f 8d 0c 03 48 8d 5c 37 ff 48 c1 eb 03 4e 8d 14 3b 4d 89 d6 4d 29 ce <49> 83 fe 10 7f 26 4d 85 f6 0f 84 39 01 00 00 48 f7 d3 4c 01 db 41
RSP: 0018:ffffc9000345fbe0 EFLAGS: 00000206
RAX: ffffffff814b6b01 RBX: 1ffff9200068bf8e RCX: ffffffff814b6b6a
RDX: 0000000000000001 RSI: 0000000000000018 RDI: ffffc9000345fc60
RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff5200068bf8c
R10: fffff5200068bf8f R11: 1ffff9200068bf8c R12: 000000000000002b
R13: dffffc0000000000 R14: 0000000000000003 R15: dffffc0000000001
FS: 00007f9442a1a6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000002006b000 CR3: 000000001e27e000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
memset+0x1e/0x40 mm/kasan/shadow.c:44
restore_altstack+0x8a/0x360 kernel/signal.c:4251
__ia32_sys_rt_sigreturn+0x660/0x790 arch/x86/kernel/signal.c:677
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: 0033:0x7f9443795e77
Code: ff ff 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
RSP: 002b:00007f9442a1a0e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f9443931f88 RCX: 00007f9443795e79
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f9443931f88
RBP: 00007f9443931f80 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f9443931f8c
R13: 0000000000000000 R14: 00007fffaba72c40 R15: 00007fffaba72d28
sched: RT throttling activated