rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-....: (1 GPs behind) idle=6c1c/1/0x4000000000000000 softirq=16622/16623 fqs=3862
rcu: 	         hardirqs   softirqs   csw/system
rcu: 	 number:  1468231          0            0
rcu: 	cputime:    14743      37725           40   ==> 52470(ms)
rcu: 	(t=10500 jiffies g=16293 q=1341 ncpus=2)
CPU: 1 PID: 7238 Comm: syz.0.383 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:211 [inline]
RIP: 0010:unwind_next_frame+0x217/0x2970 arch/x86/kernel/unwind_orc.c:494
Code: 4c 89 7c 24 48 0f 85 d7 00 00 00 49 29 df 49 c1 ef 08 8b 05 53 eb 41 0b 48 89 44 24 28 8d 68 ff 89 ef 44 89 fe e8 e9 ec 4a 00 <44> 39 fd 0f 86 4f 1d 00 00 44 89 f8 4c 8d 2c 85 94 d1 70 8f 4c 89
RSP: 0018:ffffc900001eedd8 EFLAGS: 00000246
RAX: ffffffff813aa557 RBX: ffffffff81000000 RCX: 0000000000000100
RDX: ffff888027e49e00 RSI: 000000000007631f RDI: 000000000009a000
RBP: 000000000009a000 R08: ffffc900001eef70 R09: 000000000000000c
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001eeea8
R13: dffffc0000000000 R14: ffffc900001eeedd R15: 000000000007631f
FS:  00007f73d04ae6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78ee3156c0 CR3: 000000005d0f8000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122
 kasan_save_stack mm/kasan/common.c:45 [inline]
 kasan_set_track+0x4e/0x70 mm/kasan/common.c:52
 kasan_save_free_info+0x2e/0x50 mm/kasan/generic.c:522
 ____kasan_slab_free+0x126/0x1e0 mm/kasan/common.c:236
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x280 mm/slub.c:3852
 skb_kfree_head net/core/skbuff.c:947 [inline]
 skb_free_head net/core/skbuff.c:961 [inline]
 skb_release_data+0x60a/0x800 net/core/skbuff.c:991
 skb_release_all net/core/skbuff.c:1057 [inline]
 __kfree_skb net/core/skbuff.c:1071 [inline]
 kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1107
 dev_kfree_skb_any_reason+0x10c/0x120 net/core/dev.c:3228
 free_old_xmit_skbs+0x114/0x3c0 drivers/net/virtio_net.c:780
 start_xmit+0x161/0x1420 drivers/net/virtio_net.c:2420
 __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
 sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:345
 __dev_xmit_skb net/core/dev.c:3856 [inline]
 __dev_queue_xmit+0x173e/0x35a0 net/core/dev.c:4391
 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]
 ip_finish_output2+0xcd3/0x11d0 net/ipv4/ip_output.c:235
 dst_output include/net/dst.h:467 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x10aa/0x1a10 net/ipv4/ip_output.c:535
 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422
 tcp_validate_incoming+0xf13/0x2250 net/ipv4/tcp_input.c:5891
 tcp_rcv_established+0x7d8/0x1cf0 net/ipv4/tcp_input.c:6156
 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734
 tcp_v4_rcv+0x2334/0x2a50 net/ipv4/tcp_ipv4.c:2166
 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304
 dst_input include/net/dst.h:477 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0xa38/0xd20 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3e3/0x430 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5651 [inline]
 __netif_receive_skb_list_core+0x2cc/0x740 net/core/dev.c:5689
 __netif_receive_skb_list net/core/dev.c:5751 [inline]
 netif_receive_skb_list_internal+0x91b/0xc60 net/core/dev.c:5842
 gro_normal_list include/net/gro.h:451 [inline]
 gro_normal_one include/net/gro.h:464 [inline]
 napi_skb_finish net/core/gro.c:573 [inline]
 napi_gro_receive+0x565/0xb00 net/core/gro.c:603
 receive_buf+0x218c/0x3780 drivers/net/virtio_net.c:1870
 virtnet_receive drivers/net/virtio_net.c:2155 [inline]
 virtnet_poll+0x61f/0x1180 drivers/net/virtio_net.c:2229
 __napi_poll+0xc0/0x460 net/core/dev.c:6612
 napi_poll net/core/dev.c:6679 [inline]
 net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0a d9 1a f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e2 53 ea f6 65 8b 05 d3 9a 92 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003087ca0 EFLAGS: 00000206
RAX: b2537c87d9f03f00 RBX: 0000000000000a06 RCX: b2537c87d9f03f00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffffc90003087d30 R08: ffffffff90d945ff R09: 1ffffffff21b28bf
R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: dffffc0000000000
R13: 1ffff92000610fb8 R14: ffff88802ecb0800 R15: 1ffff92000610f94
 __do_sys_perf_event_open kernel/events/core.c:12916 [inline]
 __se_sys_perf_event_open+0x1802/0x1c20 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: 0033:0x7f73cf58f749
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:00007f73d04ae038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f73cf7e5fa0 RCX: 00007f73cf58f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007f73cf613f91 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73cf7e6038 R14: 00007f73cf7e5fa0 R15: 00007ffec19d7968
 </TASK>
NMI backtrace for cpu 1
CPU: 1 PID: 7238 Comm: syz.0.383 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:preempt_count_sub+0x51/0x160 kernel/sched/core.c:5877
Code: 83 3d 82 45 8e 15 00 75 25 65 8b 05 c1 46 a8 7e 89 c1 81 e1 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
RSP: 0018:ffffc900001ee6f8 EFLAGS: 00000006
RAX: 0000000000000301 RBX: dffffc0000000000 RCX: 0000000000000300
RDX: 0000000000000100 RSI: ffffc900001f02e0 RDI: 0000000000000001
RBP: ffffc900001f02e0 R08: ffff888027e49e00 R09: 0000000000000003
R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001ee840
R13: dffffc0000000000 R14: ffffc900001f0400 R15: ffffc900001ee850
FS:  00007f73d04ae6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f78ee3156c0 CR3: 000000005d0f8000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 unwind_next_frame+0x1d07/0x2970 arch/x86/kernel/unwind_orc.c:672
 perf_callchain_kernel+0x3a8/0x5f0 arch/x86/events/core.c:2780
 get_perf_callchain+0x223/0x4d0 kernel/events/callchain.c:204
 perf_callchain kernel/events/core.c:7740 [inline]
 perf_sample_save_callchain include/linux/perf_event.h:1232 [inline]
 perf_prepare_sample+0x3a2/0x1d20 kernel/events/core.c:7784
 __perf_event_output kernel/events/core.c:7972 [inline]
 perf_event_output_forward+0x152/0x3a0 kernel/events/core.c:7993
 __perf_event_overflow+0x447/0x630 kernel/events/core.c:9718
 perf_swevent_overflow kernel/events/core.c:9794 [inline]
 perf_swevent_event+0x2f5/0x5c0 kernel/events/core.c:-1
 perf_tp_event+0x4f9/0x13a0 kernel/events/core.c:10344
 perf_trace_run_bpf_submit+0xf4/0x1c0 kernel/events/core.c:10268
 perf_trace_preemptirq_template+0x281/0x340 include/trace/events/preemptirq.h:14
 trace_irq_enable+0xbf/0xe0 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x18/0x40 kernel/trace/trace_preemptirq.c:56
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:kasan_quarantine_put+0x88/0x220 mm/kasan/quarantine.c:243
Code: e8 ed e9 ae ff 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 0f 85 83 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <48> 83 c4 08 5b 41 5c 41 5d 41 5e 41 5f c3 48 8d 80 c0 7a 03 00 45
RSP: 0018:ffffc900001ef220 EFLAGS: 00000206
RAX: b2537c87d9f03f01 RBX: ffff888076e9aa40 RCX: b2537c87d9f03f00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: ffffffff8afc6f80
RBP: ffff888076e9aa40 R08: ffffffff90d945c7 R09: 1ffffffff21b28b8
R10: dffffc0000000000 R11: fffffbfff21b28b9 R12: 0000000000000000
R13: ffffc900001ef2b8 R14: 000000000004c2c8 R15: 0000000000000282
 kasan_slab_free include/linux/kasan.h:164 [inline]
 slab_free_hook mm/slub.c:1811 [inline]
 slab_free_freelist_hook+0x130/0x1b0 mm/slub.c:1837
 slab_free mm/slub.c:3830 [inline]
 kmem_cache_free+0xf8/0x280 mm/slub.c:3852
 skb_kfree_head net/core/skbuff.c:947 [inline]
 skb_free_head net/core/skbuff.c:961 [inline]
 skb_release_data+0x60a/0x800 net/core/skbuff.c:991
 skb_release_all net/core/skbuff.c:1057 [inline]
 __kfree_skb net/core/skbuff.c:1071 [inline]
 kfree_skb_reason+0x10e/0x170 net/core/skbuff.c:1107
 dev_kfree_skb_any_reason+0x10c/0x120 net/core/dev.c:3228
 free_old_xmit_skbs+0x114/0x3c0 drivers/net/virtio_net.c:780
 start_xmit+0x161/0x1420 drivers/net/virtio_net.c:2420
 __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
 sch_direct_xmit+0x252/0x4a0 net/sched/sch_generic.c:345
 __dev_xmit_skb net/core/dev.c:3856 [inline]
 __dev_queue_xmit+0x173e/0x35a0 net/core/dev.c:4391
 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]
 ip_finish_output2+0xcd3/0x11d0 net/ipv4/ip_output.c:235
 dst_output include/net/dst.h:467 [inline]
 ip_local_out net/ipv4/ip_output.c:129 [inline]
 __ip_queue_xmit+0x10aa/0x1a10 net/ipv4/ip_output.c:535
 __tcp_transmit_skb+0x1c97/0x32a0 net/ipv4/tcp_output.c:1422
 tcp_validate_incoming+0xf13/0x2250 net/ipv4/tcp_input.c:5891
 tcp_rcv_established+0x7d8/0x1cf0 net/ipv4/tcp_input.c:6156
 tcp_v4_do_rcv+0x4ed/0xb80 net/ipv4/tcp_ipv4.c:1734
 tcp_v4_rcv+0x2334/0x2a50 net/ipv4/tcp_ipv4.c:2166
 ip_protocol_deliver_rcu+0x20e/0x3f0 net/ipv4/ip_input.c:205
 ip_local_deliver_finish+0x2ca/0x510 net/ipv4/ip_input.c:233
 NF_HOOK+0x303/0x390 include/linux/netfilter.h:304
 dst_input include/net/dst.h:477 [inline]
 ip_sublist_rcv_finish net/ipv4/ip_input.c:580 [inline]
 ip_list_rcv_finish net/ipv4/ip_input.c:631 [inline]
 ip_sublist_rcv+0xa38/0xd20 net/ipv4/ip_input.c:639
 ip_list_rcv+0x3e3/0x430 net/ipv4/ip_input.c:674
 __netif_receive_skb_list_ptype net/core/dev.c:5651 [inline]
 __netif_receive_skb_list_core+0x2cc/0x740 net/core/dev.c:5689
 __netif_receive_skb_list net/core/dev.c:5751 [inline]
 netif_receive_skb_list_internal+0x91b/0xc60 net/core/dev.c:5842
 gro_normal_list include/net/gro.h:451 [inline]
 gro_normal_one include/net/gro.h:464 [inline]
 napi_skb_finish net/core/gro.c:573 [inline]
 napi_gro_receive+0x565/0xb00 net/core/gro.c:603
 receive_buf+0x218c/0x3780 drivers/net/virtio_net.c:1870
 virtnet_receive drivers/net/virtio_net.c:2155 [inline]
 virtnet_poll+0x61f/0x1180 drivers/net/virtio_net.c:2229
 __napi_poll+0xc0/0x460 net/core/dev.c:6612
 napi_poll net/core/dev.c:6679 [inline]
 net_rx_action+0x5ea/0xbf0 net/core/dev.c:6815
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa9/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 0a d9 1a f7 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> e2 53 ea f6 65 8b 05 d3 9a 92 75 85 c0 74 3c 48 c7 04 24 0e 36
RSP: 0018:ffffc90003087ca0 EFLAGS: 00000206
RAX: b2537c87d9f03f00 RBX: 0000000000000a06 RCX: b2537c87d9f03f00
RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001
RBP: ffffc90003087d30 R08: ffffffff90d945ff R09: 1ffffffff21b28bf
R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: dffffc0000000000
R13: 1ffff92000610fb8 R14: ffff88802ecb0800 R15: 1ffff92000610f94
 __do_sys_perf_event_open kernel/events/core.c:12916 [inline]
 __se_sys_perf_event_open+0x1802/0x1c20 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: 0033:0x7f73cf58f749
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:00007f73d04ae038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a
RAX: ffffffffffffffda RBX: 00007f73cf7e5fa0 RCX: 00007f73cf58f749
RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140
RBP: 00007f73cf613f91 R08: 0000000000000002 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73cf7e6038 R14: 00007f73cf7e5fa0 R15: 00007ffec19d7968
 </TASK>