rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=cb24/1/0x4000000000000000 softirq=54017/54018 fqs=8
rcu: (detected by 0, t=10505 jiffies, g=75001, q=335 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 5141 Comm: udevd Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:get_current arch/x86/include/asm/current.h:41 [inline]
RIP: 0010:write_comp_data kernel/kcov.c:244 [inline]
RIP: 0010:__sanitizer_cov_trace_cmp8+0x8/0x80 kernel/kcov.c:293
Code: 08 04 00 00 00 48 89 7c 11 10 48 89 74 11 18 48 89 44 11 20 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0d 90 88 7c 7e 65 8b 15 91 88 7c 7e 81 e2 00 01 ff 00 74
RSP: 0018:ffffc900001f0d00 EFLAGS: 00000046
RAX: ffffffff8a78b7d8 RBX: ffff8880b8f2b990 RCX: ffff88807dfd5a00
RDX: 0000000000010000 RSI: ffff88807e4ba340 RDI: 0000000000000001
RBP: 1ffff1100fc97468 R08: ffffffff975a66bb R09: 1ffffffff2eb4cd7
R10: dffffc0000000000 R11: fffffbfff2eb4cd8 R12: ffff88807e4ba340
R13: dffffc0000000000 R14: ffff88807e4ba340 R15: 0000000000000001
FS: 00007fb16bc74880(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2d920ff8 CR3: 000000001a6ce000 CR4: 00000000003506e0
Call Trace:
<IRQ>
timerqueue_del+0x48/0x100 lib/timerqueue.c:55
__remove_hrtimer kernel/time/hrtimer.c:1133 [inline]
__run_hrtimer kernel/time/hrtimer.c:1734 [inline]
__hrtimer_run_queues+0x37f/0xc40 kernel/time/hrtimer.c:1818
hrtimer_interrupt+0x3c9/0x9c0 kernel/time/hrtimer.c:1880
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline]
__sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1088
</IRQ>
<TASK>
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 a6 14 8a ff eb 15 e8 9f 14 8a ff e8 8a 44 8b 08 4d 85 ed 74 ea e8 90 14 8a 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:ffffc90003337780 EFLAGS: 00000293
RAX: ffffffff81fd1700 RBX: 0000000000000000 RCX: ffff88807dfd5a00
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc90003337828 R08: ffffffff911cd53f R09: 1ffffffff2239aa7
R10: dffffc0000000000 R11: fffffbfff2239aa8 R12: dffffc0000000000
R13: 0000000000000200 R14: ffffffff81fcf457 R15: 1ffff92000666ef0
read_seqbegin include/linux/seqlock.h:893 [inline]
read_seqbegin_or_lock include/linux/seqlock.h:1187 [inline]
prepend_path+0x107/0x960 fs/d_path.c:166
d_absolute_path+0xa2/0x140 fs/d_path.c:234
tomoyo_get_absolute_path security/tomoyo/realpath.c:101 [inline]
tomoyo_realpath_from_path+0x2d9/0x5d0 security/tomoyo/realpath.c:271
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_path_perm+0x282/0x560 security/tomoyo/file.c:822
security_inode_getattr+0xd3/0x120 security/security.c:2154
vfs_getattr fs/stat.c:173 [inline]
vfs_statx+0x172/0x680 fs/stat.c:248
vfs_fstatat+0x12a/0x1b0 fs/stat.c:299
__do_sys_newfstatat fs/stat.c:463 [inline]
__se_sys_newfstatat fs/stat.c:457 [inline]
__x64_sys_newfstatat+0x149/0x1f0 fs/stat.c:457
do_syscall_x64 arch/x86/entry/common.c:46 [inline]
do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7fb16b511b0a
Code: 48 8b 15 f1 f2 0d 00 f7 d8 64 89 02 b8 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 41 89 ca b8 06 01 00 00 0f 05 <3d> 00 f0 ff ff 77 07 31 c0 c3 0f 1f 40 00 48 8b 15 b9 f2 0d 00 f7
RSP: 002b:00007ffe75dd2718 EFLAGS: 00000246 ORIG_RAX: 0000000000000106
RAX: ffffffffffffffda RBX: 00007ffe75dd2bb0 RCX: 00007fb16b511b0a
RDX: 00007ffe75dd2720 RSI: 00007ffe75dd2bb0 RDI: 00000000ffffff9c
RBP: 000055ed5035f910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffe75dd27b0
R13: 000055ed11d20100 R14: 0000000000000000 R15: 00007ffe75dd31d0
</TASK>
rcu: rcu_preempt kthread starved for 10465 jiffies! g75001 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:27656 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: 2901 Comm: kworker/u4:6 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:311 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfe/0x1140 kernel/smp.c:855
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 4b f7 0a 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 86 f3 0a 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 6a f3
RSP: 0018:ffffc9000b727780 EFLAGS: 00000293
RAX: ffffffff817c3826 RBX: 1ffff110171e827d RCX: ffff88802c2c0000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000b727900 R08: ffffffff911cd507 R09: 1ffffffff2239aa0
R10: dffffc0000000000 R11: fffffbfff2239aa1 R12: ffff8880b8f413e8
R13: dffffc0000000000 R14: ffff8880b8e3d1c8 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000015c0 CR3: 000000000cf32000 CR4: 00000000003506f0
Call Trace:
<TASK>
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1022
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2222 [inline]
text_poke_bp_batch+0x31e/0x990 arch/x86/kernel/alternative.c:2432
text_poke_flush arch/x86/kernel/alternative.c:2623 [inline]
text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2630
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x123/0x240 kernel/jump_label.c:207
static_key_enable+0x1a/0x20 kernel/jump_label.c:220
toggle_allocation_gate+0xa8/0x260 mm/kfence/core.c:847
process_one_work kernel/workqueue.c:2653 [inline]
process_scheduled_works+0xa5d/0x15d0 kernel/workqueue.c:2730
worker_thread+0xa55/0xfc0 kernel/workqueue.c:2811
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>