rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9074/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=37213, q=251 ncpus=2)
task:syz-executor state:R running task stack:28456 pid:9074 tgid:9074 ppid:5616 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:27 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline]
RIP: 0010:write_comp_data+0x0/0x90 kernel/kcov.c:246
Code: ae b6 02 12 48 8b 80 c8 16 00 00 c3 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <65> 8b 05 99 b6 02 12 49 89 f8 49 89 f1 49 89 d2 65 48 8b 3d 70 b6
RSP: 0018:ffffc9000313fb30 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff829732f8
RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000000000000001
RBP: ffff888056d29e00 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffff888077c06ac9
R13: dffffc0000000000 R14: ffff8880364bdc00 R15: ffff888056d29e18
rcu_read_lock include/linux/rcupdate.h:839 [inline]
__rhashtable_insert_fast include/linux/rhashtable.h:772 [inline]
rhashtable_insert_fast include/linux/rhashtable.h:885 [inline]
simple_xattr_add+0x9d8/0x1120 fs/xattr.c:1603
shmem_initxattrs+0x205/0x6c0 mm/shmem.c:4274
security_inode_init_security+0x242/0x370 security/security.c:1370
shmem_symlink+0x163/0xa00 mm/shmem.c:4098
vfs_symlink fs/namei.c:5643 [inline]
vfs_symlink+0x178/0x4d0 fs/namei.c:5622
filename_symlinkat+0x2a6/0x560 fs/namei.c:5668
__do_sys_symlinkat fs/namei.c:5688 [inline]
__se_sys_symlinkat fs/namei.c:5683 [inline]
__x64_sys_symlinkat+0x9c/0xe0 fs/namei.c:5683
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb44df9bf17
RSP: 002b:00007fffad1b4728 EFLAGS: 00000206 ORIG_RAX: 000000000000010a
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fb44df9bf17
RDX: 00007fb44e033d31 RSI: 00000000ffffff9c RDI: 00007fffad1b47c0
RBP: 00007fffad1b476c R08: 0000000000000001 R09: 00000000ffffffff
R10: 0000000000000000 R11: 0000000000000206 R12: 00000000000000a2
R13: 00000000000927c0 R14: 000000000005e55a R15: 00007fffad1b47c0
rcu: rcu_preempt kthread starved for 10502 jiffies! g37213 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:28904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1092 Comm: kworker/u8:7 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 76 62 5c 00 48 89 df 5b e9 bd ec 61 00 be 03 00 00 00 5b e9 d2 05 f1 02 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 65 8b 05 85 af 02 12 48 8b 34 24 65 48 8b 15 61 af 02
RSP: 0018:ffffc90005747868 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fc2d8d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802a25ca00
RBP: ffff8880b8540f40 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81e9 R14: 0000000000000001 R15: ffff8880b843c5c0
FS: 0000000000000000(0000) GS:ffff88812436a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fdbdb5ea540 CR3: 000000000e596000 CR4: 00000000003526f0
Call Trace:
native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x587/0x1700 kernel/smp.c:892
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1057
on_each_cpu include/linux/smp.h:72 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2773 [inline]
smp_text_poke_batch_finish+0x337/0xc60 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x37a/0x550 kernel/jump_label.c:910
static_key_enable_cpuslocked+0x1bc/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:906 [inline]
toggle_allocation_gate+0xfe/0x2d0 mm/kfence/core.c:898
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245