rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=3784/1/0x4000000000000000 softirq=147958/147958 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P18741/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=187045, q=463 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 18734 Comm: syz.4.3666 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1224 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3934 [inline]
RIP: 0010:sched_mm_cid_fork+0x681/0x10b0 kernel/sched/core.c:11002
Code: 41 5d 41 5e 41 5f 5d e9 dd 39 3d 0a 49 c7 c4 f8 de 4f 8e 49 c1 ec 03 bd 00 00 00 80 eb 0a 89 d8 f7 d8 0f 81 e1 fe ff ff f3 90 <43> 0f b6 04 2c 84 c0 75 3f 44 8b 35 97 66 ba 0c 4c 89 ff 4c 89 f6
RSP: 0018:ffffc90004defc70 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000080000000 RCX: 0000000080000001
RDX: dffffc0000000000 RSI: 0000000000000002 RDI: ffff88802b83f210
RBP: 0000000080000000 R08: 1ffff11005707ce1 R09: 0000000000000000
R10: 0000000000000000 R11: fffff520009bdf7c R12: 1ffffffff1c9fbdf
R13: dffffc0000000000 R14: 0000000000000002 R15: ffff88802b83f210
FS: 00007fd6b7c3d6c0(0000) GS:ffff888124f4b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c45d86e CR3: 000000006221c000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000007ff4 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
bprm_execve+0xe75/0x1630 fs/exec.c:1801
do_execveat_common+0x4f4/0x670 fs/exec.c:1876
__do_sys_execveat fs/exec.c:1960 [inline]
__se_sys_execveat fs/exec.c:1953 [inline]
__x64_sys_execveat+0xc7/0xf0 fs/exec.c:1953
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd6b6d9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd6b7c3d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007fd6b7025fa0 RCX: 00007fd6b6d9e0d9
RDX: 0000000000000000 RSI: 0000200000000040 RDI: ffffffffffffff9c
RBP: 00007fd6b6e35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd6b7026038 R14: 00007fd6b7025fa0 R15: 00007fd6b714fa48
task:syz.3.3669 state:R running task stack:25416 pid:18741 tgid:18740 ppid:15217 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:unwind_next_frame+0xf8/0x2550 include/linux/rcupdate.h:-1
Code: 6b c9 0e 00 75 1f c6 05 5c 6b c9 0e 01 48 c7 c7 40 b3 e9 8b be 4a 03 00 00 48 c7 c2 80 b3 e9 8b e8 9d 7d 2b 00 48 89 6c 24 38 <48> 89 5c 24 40 49 8d 5e 50 48 89 d8 48 c1 e8 03 48 89 44 24 28 42
RSP: 0018:ffffc90004f6f5a0 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff84c92d01 RCX: 0000000080000001
RDX: 00000000c8935840 RSI: ffffffff8c4bdd60 RDI: ffffffff8c4bdd20
RBP: 1ffff920009eded0 R08: ffffffff8177927f R09: 0000000000000000
R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000
R13: ffffffff8177927f R14: ffffc90004f6f648 R15: 1ffff920009edec9
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
kasan_mempool_unpoison_object include/linux/kasan.h:391 [inline]
io_alloc_cache_get io_uring/alloc_cache.h:44 [inline]
io_cache_alloc io_uring/alloc_cache.h:58 [inline]
io_uring_alloc_async_data io_uring/io_uring.h:355 [inline]
io_rw_alloc_async io_uring/rw.c:209 [inline]
__io_prep_rw+0x181/0xe70 io_uring/rw.c:268
io_prep_rw io_uring/rw.c:328 [inline]
io_prep_rwv+0x8d/0x430 io_uring/rw.c:350
io_init_req io_uring/io_uring.c:1842 [inline]
io_submit_sqe io_uring/io_uring.c:1889 [inline]
io_submit_sqes+0xbde/0x2310 io_uring/io_uring.c:2057
__do_sys_io_uring_enter io_uring/io_uring.c:2646 [inline]
__se_sys_io_uring_enter+0x35b/0x1bb0 io_uring/io_uring.c:2595
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa95739e0d9
RSP: 002b:00007fa958350f38 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 0000200000000340 RCX: 00007fa95739e0d9
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: 0000000000000afc R08: 0000000000000000 R09: 0000000000000008
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000008a0
R13: 00002000000008a8 R14: 0000000000000e26 R15: 0000000000000001
rcu: rcu_preempt kthread starved for 10502 jiffies! g187045 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 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: 1 UID: 0 PID: 3352 Comm: kworker/u8:10 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0x11e6/0x15f0 kernel/smp.c:912
Code: c0 75 7a 41 8b 1e 89 de 83 e6 01 31 ff e8 e2 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 8e 1a 0c 00 eb 37 f3 90 <41> 0f b6 04 1c 84 c0 75 10 41 f7 06 01 00 00 00 74 1e e8 73 1a 0c
RSP: 0018:ffffc9000e077700 EFLAGS: 00000293
RAX: ffffffff81baf81d RBX: dffffc0000000000 RCX: ffff8880333dbe00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000e077860 R08: ffffffff90579e37 R09: 1ffffffff20af3c6
R10: dffffc0000000000 R11: fffffbfff20af3c7 R12: 1ffff110170c85fd
R13: ffff8880b873c448 R14: ffff8880b8642fe8 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812504b000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c353a33 CR3: 000000000e946000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1077
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+0x5fd/0x1110 arch/x86/kernel/alternative.c:2983
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_enable_cpuslocked+0x128/0x240 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate+0xab/0x290 mm/kfence/core.c:911
process_one_work kernel/workqueue.c:3322 [inline]
process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486
kthread+0x388/0x470 kernel/kthread.c:436
ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
GRED: Unable to relocate VQ 0x0 after dequeue, screwing up backlog