rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5942/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=9681, q=384 ncpus=2)
task:syz-executor state:R running task stack:23944 pid:5942 tgid:5942 ppid:5939 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__kasan_check_byte+0x0/0x50 mm/kasan/common.c:571
Code: 8d 74 15 00 5d ba fe 00 00 00 41 5c 41 5d e9 47 34 00 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <0f> 1f 40 d6 41 54 49 89 f4 55 48 89 fd 53 e8 fd 24 00 00 89 c3 84
RSP: 0018:ffffc90003156d50 EFLAGS: 00000202
RAX: 0000000000000001 RBX: ffffffff8e3c9620 RCX: 0000000000000002
RDX: 0000000000000000 RSI: ffffffff816cb681 RDI: ffffffff8e3c9620
RBP: 0000000000000002 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90003156e90 R11: ffff88802bba0b30 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
kasan_check_byte include/linux/kasan.h:401 [inline]
lock_acquire kernel/locking/lockdep.c:5842 [inline]
lock_acquire+0xfc/0x330 kernel/locking/lockdep.c:5825
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
__unwind_start+0x45f/0x7f0 arch/x86/kernel/unwind_orc.c:758
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0x73/0x100 arch/x86/kernel/stacktrace.c:24
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:252 [inline]
__kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284
kasan_slab_free include/linux/kasan.h:234 [inline]
slab_free_hook mm/slub.c:2540 [inline]
slab_free mm/slub.c:6668 [inline]
kfree+0x2f8/0x6e0 mm/slub.c:6876
skb_kfree_head net/core/skbuff.c:1068 [inline]
skb_free_head+0x114/0x210 net/core/skbuff.c:1080
pskb_expand_head+0x3c4/0xf80 net/core/skbuff.c:2314
netlink_trim+0x231/0x2f0 net/netlink/af_netlink.c:1299
netlink_unicast+0xcb/0x870 net/netlink/af_netlink.c:1334
nlmsg_unicast include/net/netlink.h:1198 [inline]
rtnl_unicast net/core/rtnetlink.c:949 [inline]
rtnl_getlink+0x974/0xb80 net/core/rtnetlink.c:4199
rtnetlink_rcv_msg+0x3c9/0xe90 net/core/rtnetlink.c:6967
netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec net/socket.c:727 [inline]
__sock_sendmsg net/socket.c:742 [inline]
__sys_sendto+0x4a3/0x520 net/socket.c:2206
__do_sys_sendto net/socket.c:2213 [inline]
__se_sys_sendto net/socket.c:2209 [inline]
__x64_sys_sendto+0xe0/0x1c0 net/socket.c:2209
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f50bfb915dc
RSP: 002b:00007ffc22be7400 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f50c0914620 RCX: 00007f50bfb915dc
RDX: 0000000000000020 RSI: 00007f50c0914670 RDI: 0000000000000005
RBP: 0000000000000000 R08: 00007ffc22be7454 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000005
R13: 00007ffc22be74bc R14: 00007f50c0914670 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10550 jiffies! g9681 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:29112 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:rcu_gp_fqs_check_wake kernel/rcu/tree.c:1998 [inline]
RIP: 0010:rcu_gp_fqs_loop+0x201/0xaf0 kernel/rcu/tree.c:2083
Code: 0c 48 85 c0 74 2a 4d 85 ff 74 25 4c 89 ff e8 16 34 d6 09 49 89 c7 ba 02 04 00 00 4c 89 ee 48 c7 c7 58 4b 3d 8e e8 7f 82 f2 ff <40> f6 c5 04 74 b1 4c 89 ee 48 c7 c7 58 4b 3d 8e e8 3a 25 f2 ff b9
RSP: 0018:ffffc90000157c28 EFLAGS: 00000286
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000001 RSI: ffffffff8dacb6cd RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000001 R09: 0000000000000001
R10: ffffffff90887cd7 R11: ffff88801d6f8b30 R12: ffffffff8e011280
R13: ffffc90000157ca8 R14: 0000000000000001 R15: 0000000000000001
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 35 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xdfd/0x15e0 kernel/smp.c:877
Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 b5 5a 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 b6 05 00 00 8b 43 08 31
RSP: 0018:ffffc90000ab7808 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b84431e0 RCX: ffffffff81b28931
RDX: ffff88801eecc980 RSI: ffffffff81b2890b RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: ffff88801eecd4b0 R12: dffffc0000000000
R13: ffffed101708863d R14: 0000000000000001 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881249fd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000058 CR3: 000000000e184000 CR4: 00000000003526f0
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 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+0x27b/0xdb0 arch/x86/kernel/alternative.c:2921
arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146
jump_label_update+0x376/0x550 kernel/jump_label.c:919
static_key_enable_cpuslocked+0x1b7/0x270 kernel/jump_label.c:210
static_key_enable+0x1a/0x20 kernel/jump_label.c:223
toggle_allocation_gate mm/kfence/core.c:874 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:866
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246