rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (8599 ticks this GP) idle=5b9c/1/0x4000000000000000 softirq=61809/61819 fqs=4726 rcu: hardirqs softirqs csw/system rcu: number: 1536088 20 0 rcu: cputime: 17042 35427 38 ==> 52470(ms) rcu: (t=10500 jiffies g=73437 q=1614 ncpus=2) CPU: 1 PID: 14457 Comm: syz.7.2290 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:__sanitizer_cov_trace_switch+0x6a/0x120 kernel/kcov.c:349 Code: 00 48 83 f9 07 0f 85 cb 00 00 00 b9 07 00 00 00 48 85 c0 75 13 e9 bc 00 00 00 b9 01 00 00 00 48 85 c0 0f 84 ae 00 00 00 41 57 <41> 56 41 54 53 48 8b 54 24 20 65 4c 8b 05 c4 1f 7e 7e 45 31 c9 eb RSP: 0018:ffffc900001ef048 EFLAGS: 00000202 RAX: 0000000000000002 RBX: ffffffff8f494950 RCX: 0000000000000003 RDX: 0000000000000100 RSI: ffffffff8cb9e740 RDI: 0000000000000002 RBP: ffffc900001ef178 R08: ffffc900001ef1f0 R09: 000000000000001a R10: 0000000000000004 R11: 0000000000000100 R12: ffffc900001ef128 R13: dffffc0000000000 R14: 0000000000000002 R15: ffffffff8f494955 FS: 00007fb9e65fe6c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000006220f000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000200000000300 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: unwind_next_frame+0x655/0x2970 arch/x86/kernel/unwind_orc.c:505 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_slab_alloc+0x6c/0x80 mm/kasan/common.c:328 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4d0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x11e/0x2e0 mm/slub.c:3519 skb_clone+0x1eb/0x370 net/core/skbuff.c:1915 dev_queue_xmit_nit+0x24d/0xbb0 net/core/dev.c:2340 xmit_one net/core/dev.c:3615 [inline] dev_hard_start_xmit+0x148/0x740 net/core/dev.c:3635 __dev_queue_xmit+0x1a64/0x35a0 net/core/dev.c:4425 dev_queue_xmit include/linux/netdevice.h:3113 [inline] br_dev_queue_push_xmit+0x6a6/0x850 net/bridge/br_forward.c:53 NF_HOOK+0x613/0x6a0 include/linux/netfilter.h:304 br_nf_post_routing+0xb41/0xfb0 net/bridge/br_netfilter_hooks.c:977 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:259 [inline] NF_HOOK+0x213/0x3d0 include/linux/netfilter.h:302 br_forward_finish+0xd3/0x130 net/bridge/br_forward.c:66 br_nf_hook_thresh net/bridge/br_netfilter_hooks.c:-1 [inline] br_nf_forward_finish+0xa33/0xe50 net/bridge/br_netfilter_hooks.c:684 NF_HOOK+0x613/0x6a0 include/linux/netfilter.h:304 br_nf_forward_ip+0xcc1/0x1110 net/bridge/br_netfilter_hooks.c:754 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_slow+0xbd/0x200 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:259 [inline] NF_HOOK+0x213/0x3d0 include/linux/netfilter.h:302 __br_forward+0x41f/0x600 net/bridge/br_forward.c:115 br_handle_frame_finish+0x143d/0x1950 net/bridge/br_input.c:215 br_nf_hook_thresh+0x3b6/0x480 net/bridge/br_netfilter_hooks.c:1184 br_nf_pre_routing_finish_ipv6+0x9e3/0xd90 net/bridge/br_netfilter_ipv6.c:-1 NF_HOOK include/linux/netfilter.h:304 [inline] br_nf_pre_routing_ipv6+0x34d/0x680 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:144 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x957/0x14c0 net/bridge/br_input.c:424 __netif_receive_skb_core+0xf6b/0x3ac0 net/core/dev.c:5502 __netif_receive_skb_one_core net/core/dev.c:5606 [inline] __netif_receive_skb+0x74/0x290 net/core/dev.c:5722 process_backlog+0x380/0x6e0 net/core/dev.c:6050 __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:generic_exec_single+0x476/0x4f0 kernel/smp.c:418 Code: 75 11 e8 cd e6 0a 00 48 85 db 75 16 e8 c3 e6 0a 00 eb 15 e8 bc e6 0a 00 e8 47 cd ec 08 48 85 db 74 ea e8 ad e6 0a 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 04 2c 00 00 00 00 66 43 c7 44 2c RSP: 0018:ffffc9000c257a00 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: 0000000000080000 RDX: ffffc9000cfb9000 RSI: 000000000000627f RDI: 0000000000006280 RBP: ffffc9000c257ad0 R08: ffffffff90d945ff R09: 1ffffffff21b28bf R10: dffffc0000000000 R11: fffffbfff21b28c0 R12: 1ffff9200184af44 R13: dffffc0000000000 R14: 0000000000000000 R15: 1ffff9200184af65 smp_call_function_single+0x352/0x580 kernel/smp.c:647 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: 0033:0x7fb9e578f749 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:00007fb9e65fe038 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007fb9e59e5fa0 RCX: 00007fb9e578f749 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000200000000140 RBP: 00007fb9e5813f91 R08: 0000000000000002 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb9e59e6038 R14: 00007fb9e59e5fa0 R15: 00007ffdb7a15338