syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P10842/2:b..l
	(detected by 0, t=10503 jiffies, g=32393, q=428)
task:syz.8.1394      state:R  running task     stack:22840 pid:10842 ppid:  8045 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6779
 irqentry_exit+0x53/0x80 kernel/entry/common.c:432
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:skb_tail_pointer include/linux/skbuff.h:2324 [inline]
RIP: 0010:skb_put+0x31/0x1f0 net/core/skbuff.c:2029
Code: 41 54 53 48 83 ec 18 41 89 f5 48 89 fb 49 be 00 00 00 00 00 fc ff df e8 3d 2d 30 f9 48 8d bb c8 00 00 00 48 89 f8 48 c1 e8 03 <42> 80 3c 30 00 74 05 e8 73 1f 7a f9 4c 8b bb c8 00 00 00 4c 8d a3
RSP: 0018:ffffc90002feec58 EFLAGS: 00000a02
RAX: 1ffff1100c3ba331 RBX: ffff888061dd18c0 RCX: 0000000000080000
RDX: ffffc90017eb9000 RSI: 000000000007ffff RDI: ffff888061dd1988
RBP: 0000000000000001 R08: ffffffff893c2e83 R09: ffff88807a2ce855
R10: 0000000000000000 R11: dffffc0000000001 R12: ffffffff8dd386f0
R13: 0000000000000048 R14: dffffc0000000000 R15: ffffffff8dd38718
 skb_put_zero include/linux/skbuff.h:2402 [inline]
 dump_ah_combs net/key/af_key.c:2970 [inline]
 pfkey_send_acquire+0x10e9/0x2d40 net/key/af_key.c:3242
 km_query+0xec/0x1d0 net/xfrm/xfrm_state.c:2247
 xfrm_state_find+0x21aa/0x2f20 net/xfrm/xfrm_state.c:1164
 xfrm_tmpl_resolve_one net/xfrm/xfrm_policy.c:2417 [inline]
 xfrm_tmpl_resolve net/xfrm/xfrm_policy.c:2462 [inline]
 xfrm_resolve_and_create_bundle+0x774/0x3110 net/xfrm/xfrm_policy.c:2757
 xfrm_lookup_with_ifid+0x31a/0x2420 net/xfrm/xfrm_policy.c:3091
 xfrm_lookup net/xfrm/xfrm_policy.c:3220 [inline]
 xfrm_lookup_route+0x38/0x1a0 net/xfrm/xfrm_policy.c:3231
 udp_sendmsg+0x1a84/0x2e80 net/ipv4/udp.c:1245
 sock_sendmsg_nosec net/socket.c:704 [inline]
 __sock_sendmsg net/socket.c:716 [inline]
 ____sys_sendmsg+0x59e/0x8f0 net/socket.c:2436
 ___sys_sendmsg+0x252/0x2e0 net/socket.c:2490
 __sys_sendmmsg+0x2bf/0x560 net/socket.c:2576
 __do_sys_sendmmsg net/socket.c:2605 [inline]
 __se_sys_sendmmsg net/socket.c:2602 [inline]
 __x64_sys_sendmmsg+0x9c/0xb0 net/socket.c:2602
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc50b299169
RSP: 002b:00007fc5090e1038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fc50b4b2080 RCX: 00007fc50b299169
RDX: 000000000800001d RSI: 0000200000007fc0 RDI: 0000000000000007
RBP: 00007fc50b31a2a0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fc50b4b2080 R15: 00007fff97070448
 </TASK>
rcu: rcu_preempt kthread starved for 10536 jiffies! g32393 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:26752 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5029 [inline]
 __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375
 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6551
 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6576
 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34
 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline]
 _raw_spin_unlock_irqrestore+0x128/0x130 kernel/locking/spinlock.c:194
 debug_object_free+0x2b9/0x460 lib/debugobjects.c:851
 destroy_timer_on_stack kernel/time/timer.c:759 [inline]
 schedule_timeout+0x1d0/0x300 kernel/time/timer.c:1918
 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145
 kthread+0x3f6/0x4f0 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 0
CPU: 0 PID: 10870 Comm: syz.7.1399 Not tainted 5.15.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x1e3/0x2d0 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x46a/0x4a0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x181/0x2a0 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1d2/0x240 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x137a/0x14d0 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3932 [inline]
 rcu_sched_clock_irq+0xa38/0x1150 kernel/rcu/tree.c:2619
 update_process_times+0x196/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1688 [inline]
 __hrtimer_run_queues+0x55b/0xcf0 kernel/time/hrtimer.c:1752
 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1814
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x13b/0x4b0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 31 60 f6 ff 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ce 67 19 f7 48 89 df e8 26 bc 1a f7 e8 11 7c 3d f7 fb bf 01 00 00 00 <e8> 16 00 0e f7 65 8b 05 87 d0 b8 75 85 c0 74 02 5b c3 e8 54 ed b6
RSP: 0018:ffffc9000350fbc0 EFLAGS: 00000282
RAX: eba8bf858ddb1a00 RBX: ffff88802ab82500 RCX: ffffffff96a95f03
RDX: dffffc0000000000 RSI: ffffffff8aab2a60 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffffffff81871b70 R09: ffffed10055704a1
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000000
R13: dffffc0000000000 R14: ffffc9000350fe00 R15: ffff88802ab82500
 spin_unlock_irq include/linux/spinlock.h:413 [inline]
 get_signal+0x13ee/0x14e0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x5d/0x240 kernel/entry/common.c:307
 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fc1778d9169
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:00007fc1757000e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fc177af2168 RCX: 00007fc1778d9169
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fc177af2168
RBP: 00007fc177af2160 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc177af216c
R13: 0000000000000000 R14: 00007ffc8b82b920 R15: 00007ffc8b82ba08
 </TASK>