rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=bbf4/1/0x4000000000000000 softirq=379557/379559 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P14731/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=384017, q=205 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14696 Comm: syz.3.12161 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
RIP: 0010:num_possible_cpus include/linux/cpumask.h:1222 [inline]
RIP: 0010:mm_get_cid kernel/sched/sched.h:3782 [inline]
RIP: 0010:sched_mm_cid_fork+0x2f6/0xc20 kernel/sched/core.c:10582
Code: 01 00 00 85 ed 0f 84 0b 01 00 00 31 ed 31 db e9 c1 01 00 00 49 c7 c5 c8 a4 f7 8d 49 c1 ed 03 eb 07 44 89 e0 f7 d8 71 8d f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 50 44 8b
RSP: 0018:ffffc90004a5fc78 EFLAGS: 00000887
RAX: 0000000080000000 RBX: 0000000000000002 RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000000002 RDI: ffff88802272bc90
RBP: ffff88802272bc90 R08: 1ffff110044e5641 R09: ffff88802272b354
R10: ffff88802272b210 R11: fffff5200094bf80 R12: 0000000080000000
R13: 1ffffffff1bef499 R14: 0000000000000002 R15: ffff88802272b100
FS: 00007f642f2c46c0(0000) GS:ffff8881257f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f43f89cde9c CR3: 00000000884ae000 CR4: 00000000003526f0
Call Trace:
bprm_execve+0xda1/0x1410 fs/exec.c:1776
do_execveat_common+0x50f/0x690 fs/exec.c:1859
do_execveat fs/exec.c:1944 [inline]
__do_sys_execveat fs/exec.c:2018 [inline]
__se_sys_execveat fs/exec.c:2012 [inline]
__x64_sys_execveat+0xc4/0xe0 fs/exec.c:2012
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f642e39aeb9
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:00007f642f2c4028 EFLAGS: 00000246 ORIG_RAX: 0000000000000142
RAX: ffffffffffffffda RBX: 00007f642e615fa0 RCX: 00007f642e39aeb9
RDX: 0000000000000000 RSI: 0000200000000000 RDI: 0000000000000005
RBP: 00007f642e408c1f R08: 0000000000001000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f642e616038 R14: 00007f642e615fa0 R15: 00007f642e73fa48
task:syz-executor state:R running task stack:28120 pid:14731 tgid:14731 ppid:6168 task_flags:0x400040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194
irqentry_exit+0x597/0x620 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__radix_tree_lookup lib/radix-tree.c:768 [inline]
RIP: 0010:radix_tree_lookup+0x125/0x290 lib/radix-tree.c:819
Code: d8 44 89 f9 48 d3 e8 83 e0 3f 4d 8d 3c c4 49 83 c7 28 4c 89 f8 48 c1 e8 03 80 3c 28 00 74 08 4c 89 ff e8 6e f8 9a f6 4d 8b 3f <49> 81 ff 02 04 00 00 0f 84 a2 00 00 00 4c 89 e0 48 c1 e8 03 0f b6
RSP: 0018:ffffc900043476a8 EFLAGS: 00000246
RAX: 1ffff1100f2ec1d3 RBX: 00000000000005b6 RCX: 0000000000000006
RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000040
RBP: dffffc0000000000 R08: ffffffff82671024 R09: ffffffff8e55a360
R10: dffffc0000000000 R11: ffffffff8266f0e0 R12: ffff888079760dc0
R13: 0000000000000fff R14: ffff888026aac2f8 R15: ffff88802579d602
find_pid_ns kernel/pid.c:320 [inline]
find_task_by_pid_ns+0x55/0x1b0 kernel/pid.c:435
proc_pid_lookup+0x157/0x420 fs/proc/base.c:3516
proc_root_lookup+0x20/0x50 fs/proc/root.c:405
__lookup_slow+0x2b7/0x410 fs/namei.c:1866
lookup_slow+0x53/0x70 fs/namei.c:1883
walk_component fs/namei.c:2229 [inline]
link_path_walk+0x1273/0x18d0 fs/namei.c:2594
path_openat+0x2bf/0x3e20 fs/namei.c:4792
do_filp_open+0x22d/0x490 fs/namei.c:4823
do_sys_openat2+0x12f/0x220 fs/open.c:1430
do_sys_open fs/open.c:1436 [inline]
__do_sys_openat fs/open.c:1452 [inline]
__se_sys_openat fs/open.c:1447 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1447
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4876b5b78e
RSP: 002b:00007f4876f3f7f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 0000555563b1d500 RCX: 00007f4876b5b78e
RDX: 0000000000080001 RSI: 00007f4876c0ac11 RDI: ffffffffffffff9c
RBP: 00007f4876c0ac11 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: 00007f4876f3f8d0 R14: 00000000002b90ef R15: 00007f4876f3fe40
rcu: rcu_preempt kthread starved for 10506 jiffies! g384017 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:27936 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5260 [inline]
__schedule+0x14ea/0x5050 kernel/sched/core.c:6867
__schedule_loop kernel/sched/core.c:6949 [inline]
schedule+0x164/0x360 kernel/sched/core.c:6964
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 1110 Comm: kworker/u8:6 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xce5/0x1270 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 c4 db 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 6f d7 0b 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 53 d7
RSP: 0018:ffffc90003c3f6a0 EFLAGS: 00000293
RAX: ffffffff81b89ffd RBX: 1ffff110170e8129 RCX: ffff888026e40000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90003c3f7e0 R08: ffffffff8fef1b77 R09: 1ffffffff1fde36e
R10: dffffc0000000000 R11: fffffbfff1fde36f R12: ffff8880b8740948
R13: dffffc0000000000 R14: ffff8880b863bb00 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881256f5000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4876babb40 CR3: 000000000e346000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
on_each_cpu include/linux/smp.h:71 [inline]
smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2711 [inline]
smp_text_poke_batch_finish+0x5f5/0x1160 arch/x86/kernel/alternative.c:2921
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
static_key_disable_cpuslocked+0xc5/0x1a0 kernel/jump_label.c:240
static_key_disable+0x1a/0x20 kernel/jump_label.c:248
toggle_allocation_gate+0x1fe/0x290 mm/kfence/core.c:901
process_one_work kernel/workqueue.c:3257 [inline]
process_scheduled_works+0xaec/0x17a0 kernel/workqueue.c:3340
worker_thread+0xda6/0x1360 kernel/workqueue.c:3421
kthread+0x726/0x8b0 kernel/kthread.c:463
ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246