BUG: please report to dccp@vger.kernel.org => prev = 0, last = 0 at net/dccp/ccids/lib/packet_history.c:417/tfrc_rx_hist_sample_rtt() CPU: 1 UID: 0 PID: 12 Comm: kworker/u8:1 Not tainted 6.13.0-rc7-syzkaller-00108-g70d81f25cc92 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 tfrc_rx_hist_sample_rtt+0x397/0x4b0 net/dccp/ccids/lib/packet_history.c:414 ccid3_hc_rx_packet_recv+0x69d/0xe60 net/dccp/ccids/ccid3.c:760 ccid_hc_rx_packet_recv net/dccp/ccid.h:182 [inline] dccp_deliver_input_to_ccids net/dccp/input.c:176 [inline] dccp_rcv_established+0x1bb/0x320 net/dccp/input.c:374 dccp_v4_do_rcv+0xff/0x1f0 net/dccp/ipv4.c:680 sk_backlog_rcv include/net/sock.h:1121 [inline] __sk_receive_skb+0x82b/0x8b0 net/core/sock.c:568 ip_protocol_deliver_rcu+0x2e9/0x440 net/ipv4/ip_input.c:205 ip_local_deliver_finish+0x341/0x5f0 net/ipv4/ip_input.c:233 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5704 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5817 process_backlog+0x662/0x15b0 net/core/dev.c:6149 __napi_poll+0xcb/0x490 net/core/dev.c:6902 napi_poll net/core/dev.c:6971 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7093 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xd8/0x140 kernel/locking/spinlock.c:194 Code: 9c 8f 44 24 20 42 80 3c 23 00 74 08 4c 89 f7 e8 7e 1f 3a f6 f6 44 24 21 02 75 52 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 43 c6 a1 f5 65 8b 05 b4 08 38 74 85 c0 74 43 48 c7 04 24 0e 36 RSP: 0018:ffffc900001179e0 EFLAGS: 00000206 RAX: d2918385d9af5f00 RBX: 1ffff92000022f40 RCX: ffffffff817b387a RDX: dffffc0000000000 RSI: ffffffff8c0a98e0 RDI: 0000000000000001 RBP: ffffc90000117a68 R08: ffffffff942a589f R09: 1ffffffff2854b13 R10: dffffc0000000000 R11: fffffbfff2854b14 R12: dffffc0000000000 R13: 1ffff92000022f3c R14: ffffc90000117a00 R15: 0000000000000246 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] prepare_to_wait_event+0x3bd/0x400 kernel/sched/wait.c:300 toggle_allocation_gate+0x185/0x260 mm/kfence/core.c:851 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xa66/0x1840 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 ---------------- Code disassembly (best guess): 0: 9c pushf 1: 8f 44 24 20 pop 0x20(%rsp) 5: 42 80 3c 23 00 cmpb $0x0,(%rbx,%r12,1) a: 74 08 je 0x14 c: 4c 89 f7 mov %r14,%rdi f: e8 7e 1f 3a f6 call 0xf63a1f92 14: f6 44 24 21 02 testb $0x2,0x21(%rsp) 19: 75 52 jne 0x6d 1b: 41 f7 c7 00 02 00 00 test $0x200,%r15d 22: 74 01 je 0x25 24: fb sti 25: bf 01 00 00 00 mov $0x1,%edi * 2a: e8 43 c6 a1 f5 call 0xf5a1c672 <-- trapping instruction 2f: 65 8b 05 b4 08 38 74 mov %gs:0x743808b4(%rip),%eax # 0x743808ea 36: 85 c0 test %eax,%eax 38: 74 43 je 0x7d 3a: 48 rex.W 3b: c7 .byte 0xc7 3c: 04 24 add $0x24,%al 3e: 0e (bad) 3f: 36 ss