rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=f61c/1/0x4000000000000000 softirq=41794/41795 fqs=2857 rcu: hardirqs softirqs csw/system rcu: number: 1490442 0 0 rcu: cputime: 15132 37346 45 ==> 52480(ms) rcu: (t=10500 jiffies g=47541 q=721 ncpus=2) CPU: 1 PID: 12189 Comm: syz.7.1792 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline] RIP: 0010:write_comp_data kernel/kcov.c:245 [inline] RIP: 0010:__sanitizer_cov_trace_cmp4+0x1f/0x90 kernel/kcov.c:287 Code: 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 48 8b 04 24 65 48 8b 15 70 23 7e 7e 65 8b 0d 71 23 7e 7e 81 e1 00 01 ff 00 74 11 <81> f9 00 01 00 00 75 5b 83 ba 1c 16 00 00 00 74 52 8b 8a f8 15 00 RSP: 0018:ffffc900001ef7b0 EFLAGS: 00000206 RAX: ffffffff813abf87 RBX: ffffc900001ef8c0 RCX: 0000000000000100 RDX: ffff8880276ebc00 RSI: 0000000000000001 RDI: 0000000000000001 RBP: 0000000000000001 R08: ffff8880276ebc00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001ef888 R13: dffffc0000000000 R14: 0000000000000001 R15: ffffffff8f69f2ea FS: 00007f588a4356c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffccecdab50 CR3: 00000000305f9000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x1c47/0x2970 arch/x86/kernel/unwind_orc.c:664 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 tcp_data_queue+0x151/0x5a80 net/ipv4/tcp_input.c:5165 tcp_rcv_established+0xa39/0x1cf0 net/ipv4/tcp_input.c:6171 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+0x578/0x740 net/core/dev.c:5699 __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 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:7009 Code: 44 24 20 f6 44 24 21 02 74 0b 0f 0b 48 f7 03 08 00 00 00 74 63 bf 01 00 00 00 e8 8b b3 eb f6 e8 26 3a 1c f7 fb bf 01 00 00 00 db b5 ff ff 48 c7 44 24 40 00 00 00 00 9c 8f 44 24 40 8b 44 24 RSP: 0018:ffffc900034c7680 EFLAGS: 00000282 RAX: 2a25e0c2e5e64100 RBX: 0000000000000000 RCX: 2a25e0c2e5e64100 RDX: dffffc0000000000 RSI: ffffffff8aaabce0 RDI: 0000000000000001 RBP: ffffc900034c7730 R08: ffffffff8e4a212f R09: 1ffffffff1c94425 R10: dffffc0000000000 R11: fffffbfff1c94426 R12: 0000000000000000 R13: 0000000000000000 R14: dffffc0000000000 R15: 1ffff92000698ed0 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_is_held_type+0xb/0x190 kernel/locking/lockdep.c:5810 Code: c7 c7 80 bb aa 8a 48 c7 c6 c0 bb aa 8a e8 2d 93 e8 f6 0f 0b eb bf e8 84 fc ff ff 0f 1f 40 00 f3 0f 1e fa 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 bd RSP: 0018:ffffc900034c77f8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff92000698f0c RCX: ffff8880276ebc00 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffffffff8cd2ff80 RBP: ffffc900034c7938 R08: ffffc900034c7a5f R09: 0000000000000000 R10: ffffc900034c7a28 R11: fffff52000698f4c R12: ffffc900034c7a20 R13: dffffc0000000000 R14: dffffc0000000000 R15: ffff8880276ec140 lock_is_held include/linux/lockdep.h:288 [inline] __might_resched+0xa7/0x610 kernel/sched/core.c:10170 down_read+0x22/0x2e0 kernel/locking/rwsem.c:1519 mmap_read_lock include/linux/mmap_lock.h:146 [inline] acct_collect+0x166/0x750 kernel/acct.c:598 do_exit+0x816/0x23c0 kernel/exit.c:853 do_group_exit+0x21b/0x2d0 kernel/exit.c:1024 get_signal+0x12fc/0x1400 kernel/signal.c:2902 arch_do_signal_or_restart+0x9c/0x7b0 arch/x86/kernel/signal.c:310 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xf6/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline] syscall_exit_to_user_mode+0x1a/0x50 kernel/entry/common.c:302 do_syscall_64+0x61/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f588958f749 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:00007f588a435038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: 0000000000000007 RBX: 00007f58897e5fa0 RCX: 00007f588958f749 RDX: ffffffdfffffffff RSI: 0000000000000000 RDI: 00002000000000c0 RBP: 00007f5889613f91 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f58897e6038 R14: 00007f58897e5fa0 R15: 00007ffd8f92cda8