rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=bfa4/1/0x4000000000000000 softirq=26489/26507 fqs=0
rcu: (detected by 0, t=10502 jiffies, g=14825, q=301 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 7842 Comm: syz.2.512 Not tainted 6.15.0-rc2-syzkaller-00400-g3088d26962e8 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:iterate_chain_key kernel/locking/lockdep.c:453 [inline]
RIP: 0010:__lock_acquire+0x610/0x1ba0 kernel/locking/lockdep.c:5223
Code: e0 0d 44 09 e0 98 29 f8 8b 7c 24 18 31 f8 89 c2 29 c6 01 c8 c1 c2 06 31 f2 29 d1 89 ce 89 d1 01 c2 c1 c1 08 31 f1 89 ce 29 c8 <01> d1 c1 c6 10 89 cf 31 f0 89 c6 29 c2 01 c8 c1 ce 0d 31 d6 89 f2
RSP: 0018:ffffc90000a08ce8 EFLAGS: 00000006
RAX: 00000000001bf57d RBX: ffff88807fa1d370 RCX: 00000000ffe40a12
RDX: 00000000ffffe3a0 RSI: 00000000ffe40a12 RDI: 00000000ffffffff
RBP: ffff88807fa1d370 R08: 0000000000080000 R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000006d
R13: 0000000000000000 R14: ffff88807fa1c880 R15: 0000000000000000
FS: 00007f56498c16c0(0000) GS:ffff888124ab2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b30017ff8 CR3: 00000000323c8000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
lock_acquire kernel/locking/lockdep.c:5866 [inline]
lock_acquire+0x179/0x350 kernel/locking/lockdep.c:5823
__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline]
_raw_spin_lock_irq+0x36/0x50 kernel/locking/spinlock.c:170
__run_hrtimer kernel/time/hrtimer.c:1765 [inline]
__hrtimer_run_queues+0x2bc/0xad0 kernel/time/hrtimer.c:1825
hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline]
__sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x107/0x150 kernel/locking/lockdep.c:5943
Code: 00 00 b8 ff ff ff ff 65 0f c1 05 6c 97 34 08 83 f8 01 75 2d 9c 58 f6 c4 02 75 43 48 f7 04 24 00 02 00 00 74 01 fb 48 83 c4 08 <44> 89 e8 5b 5d 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 45 31 ed eb
RSP: 0018:ffffc90003e1f978 EFLAGS: 00000286
RAX: 0000000000000046 RBX: 1ffff920007c3f38 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8dbca21f RDI: ffffffff8bf46440
RBP: ffffffff8e3bf500 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807fa1c880
R13: 0000000000000000 R14: 00000000ffffffff R15: 0000000000000000
lock_is_held include/linux/lockdep.h:249 [inline]
__might_resched+0x4ca/0x5e0 kernel/sched/core.c:8780
__might_fault+0x83/0x190 mm/memory.c:7149
_inline_copy_from_user include/linux/uaccess.h:162 [inline]
_copy_from_user+0x29/0xd0 lib/usercopy.c:18
copy_from_user include/linux/uaccess.h:212 [inline]
copy_msghdr_from_user+0x98/0x160 net/socket.c:2496
recvmsg_copy_msghdr net/socket.c:2752 [inline]
___sys_recvmsg+0xdb/0x1a0 net/socket.c:2824
do_recvmmsg+0x2fe/0x740 net/socket.c:2923
__sys_recvmmsg net/socket.c:2997 [inline]
__do_sys_recvmmsg net/socket.c:3020 [inline]
__se_sys_recvmmsg net/socket.c:3013 [inline]
__x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3013
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f564898e169
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f56498c1038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f5648bb6080 RCX: 00007f564898e169
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f5648a10a68 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f5648bb6080 R15: 00007ffdfb8d1318
rcu: rcu_preempt kthread starved for 10502 jiffies! g14825 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:27704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5382 [inline]
__schedule+0x116f/0x5de0 kernel/sched/core.c:6767
__schedule_loop kernel/sched/core.c:6845 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6860
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046
rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
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: 1157 Comm: kworker/u8:8 Not tainted 6.15.0-rc2-syzkaller-00400-g3088d26962e8 #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Workqueue: events_unbound toggle_allocation_gate
RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline]
RIP: 0010:smp_call_function_many_cond+0x4aa/0x1290 kernel/smp.c:885
Code: 0c 00 85 ed 74 48 48 8b 44 24 20 49 89 c4 83 e0 07 49 c1 ec 03 48 89 c5 4d 01 f4 83 c5 03 e8 fd 16 0c 00 f3 90 41 0f b6 04 24 <40> 38 c5 7c 08 84 c0 0f 85 de 0b 00 00 8b 43 08 31 ff 83 e0 01 41
RSP: 0018:ffffc90003f6f938 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffff8880b853f740 RCX: ffffffff81af38b9
RDX: ffff888027fea440 RSI: ffffffff81af3893 RDI: 0000000000000005
RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffed10170a7ee9
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff8880b843b040
FS: 0000000000000000(0000) GS:ffff8881249b2000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd9aeee56c0 CR3: 000000000e180000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1052
on_each_cpu include/linux/smp.h:71 [inline]
text_poke_sync arch/x86/kernel/alternative.c:2455 [inline]
text_poke_bp_batch+0x220/0x760 arch/x86/kernel/alternative.c:2665
text_poke_flush arch/x86/kernel/alternative.c:2856 [inline]
text_poke_flush arch/x86/kernel/alternative.c:2853 [inline]
text_poke_finish+0x30/0x40 arch/x86/kernel/alternative.c:2863
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:850 [inline]
toggle_allocation_gate+0xfa/0x280 mm/kfence/core.c:842
process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
process_scheduled_works kernel/workqueue.c:3319 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
kthread+0x3c2/0x780 kernel/kthread.c:464
ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245