rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=8af4/1/0x4000000000000000 softirq=80255/80256 fqs=4634 rcu: hardirqs softirqs csw/system rcu: number: 1377712 0 0 rcu: cputime: 17623 34856 45 ==> 52480(ms) rcu: (t=10500 jiffies g=102121 q=1040 ncpus=2) CPU: 1 PID: 19044 Comm: syz.7.3946 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:preempt_count_sub+0x65/0x160 kernel/sched/core.c:5884 Code: ff ff ff 7f 39 cf 7f 25 81 ff ff 00 00 00 0f 93 c1 84 c0 0f 95 c0 08 c8 74 53 65 8b 05 9c 46 a8 7e f7 df 65 01 3d 93 46 a8 7e <5b> 5d c3 e8 43 67 c0 02 85 c0 74 f4 48 c7 c0 f0 55 4a 8e 48 c1 e8 RSP: 0018:ffffc900001efa58 EFLAGS: 00000213 RAX: 0000000000000305 RBX: dffffc0000000000 RCX: 0000000000000300 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 00000000ffffffff RBP: 00000000000002c0 R08: ffffffff90d9456f R09: 1ffffffff21b28ad R10: dffffc0000000000 R11: fffffbfff21b28ae R12: ffff8881432408c0 R13: ffff88801a7ea3c0 R14: 0000000000082820 R15: ffff8881432408c0 FS: 00007fc0c9a056c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000048c9a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __slab_alloc mm/slub.c:3341 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] kmem_cache_alloc_node+0x1f7/0x330 mm/slub.c:3540 kmalloc_reserve+0x95/0x240 net/core/skbuff.c:562 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 skb_copy+0x13d/0x7a0 net/core/skbuff.c:1987 mac80211_hwsim_tx_frame_no_nl+0xc81/0x1170 drivers/net/wireless/virtual/mac80211_hwsim.c:1840 mac80211_hwsim_tx+0x184a/0x2570 drivers/net/wireless/virtual/mac80211_hwsim.c:2058 drv_tx net/mac80211/driver-ops.h:37 [inline] wake_tx_push_queue net/mac80211/util.c:305 [inline] ieee80211_handle_wake_tx_queue+0x18c/0x2a0 net/mac80211/util.c:322 drv_wake_tx_queue net/mac80211/driver-ops.h:1251 [inline] schedule_and_wake_txq net/mac80211/driver-ops.h:1258 [inline] ieee80211_queue_skb+0x1a11/0x2140 net/mac80211/tx.c:1678 ieee80211_tx+0x298/0x420 net/mac80211/tx.c:1980 __ieee80211_subif_start_xmit+0xdd8/0x14c0 net/mac80211/tx.c:4333 ieee80211_subif_start_xmit+0xe1/0x500 net/mac80211/tx.c:4527 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3619 [inline] dev_hard_start_xmit+0x246/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 dev_queue_xmit include/linux/netdevice.h:3113 [inline] neigh_hh_output include/net/neighbour.h:527 [inline] neigh_output include/net/neighbour.h:541 [inline] ip6_finish_output2+0xdf5/0x1650 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xbed/0x14b0 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x2bc/0x600 net/ipv6/addrconf.c:4006 call_timer_fn+0x16e/0x530 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x52d/0x7d0 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xc7/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:finish_task_switch+0x26a/0x920 kernel/sched/core.c:5254 Code: 0f 84 37 01 00 00 48 85 db 0f 85 56 01 00 00 0f 1f 44 00 00 4c 8b 75 d0 4c 89 e7 e8 80 ca 14 09 e8 4b a4 2f 00 fb 4c 8b 65 c0 <49> 8d bc 24 f8 15 00 00 48 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 RSP: 0018:ffffc900045bf778 EFLAGS: 00000286 RAX: 20a96ced65689700 RBX: 0000000000000000 RCX: 20a96ced65689700 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80 RBP: ffffc900045bf7d0 R08: ffffffff90d945ff R09: 1ffffffff21b28bf R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: ffff88804d91bc00 R13: dffffc0000000000 R14: ffff8880292fbc00 R15: ffff8880b8f3cac8 context_switch kernel/sched/core.c:5383 [inline] __schedule+0x14da/0x44d0 kernel/sched/core.c:6699 preempt_schedule_common+0x82/0xc0 kernel/sched/core.c:6866 preempt_schedule+0xab/0xc0 kernel/sched/core.c:6890 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:45 smp_call_function_single+0x469/0x580 kernel/smp.c:652 task_function_call kernel/events/core.c:120 [inline] perf_install_in_context+0x591/0x8e0 kernel/events/core.c:2948 __do_sys_perf_event_open kernel/events/core.c:12915 [inline] __se_sys_perf_event_open+0x17fa/0x1c20 kernel/events/core.c:12567 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fc0c8b8f749 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:00007fc0c9a05038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fc0c8de5fa0 RCX: 00007fc0c8b8f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fc0c8c13f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fc0c8de6038 R14: 00007fc0c8de5fa0 R15: 00007ffed2500f58