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: 0 UID: 0 PID: 6309 Comm: syz-executor.0 Not tainted 6.14.0-rc5-syzkaller-g99fa936e8e4f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <IRQ>
 __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:681
 sk_backlog_rcv include/net/sock.h:1122 [inline]
 __sk_receive_skb+0x82b/0x8b0 net/core/sock.c:575
 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:5893 [inline]
 __netif_receive_skb+0x2bf/0x650 net/core/dev.c:6006
 process_backlog+0x662/0x15b0 net/core/dev.c:6354
 __napi_poll+0xcb/0x490 net/core/dev.c:7188
 napi_poll net/core/dev.c:7257 [inline]
 net_rx_action+0x89b/0x1240 net/core/dev.c:7379
 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
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x170/0x200 kernel/softirq.c:396
Code: 8c e8 74 6f 7d 0a 65 66 8b 05 04 98 80 7e 66 85 c0 75 5d bf 01 00 00 00 e8 7d 25 0c 00 e8 a8 4e 46 00 fb 65 8b 05 c8 97 80 7e <85> c0 75 05 e8 57 01 a7 ff 48 c7 44 24 20 0e 36 e0 45 49 c7 04 1c
RSP: 0018:ffffc90004f07660 EFLAGS: 00000286
RAX: 0000000080000000 RBX: 1ffff920009e0ed0 RCX: ffffffff819d2a9a
RDX: dffffc0000000000 RSI: ffffffff8c2aa4a0 RDI: ffffffff8c801c20
RBP: ffffc90004f07710 R08: ffffffff9451490f R09: 1ffffffff28a2921
R10: dffffc0000000000 R11: fffffbfff28a2922 R12: dffffc0000000000
R13: 1ffff920009e0ed4 R14: ffffc90004f076a0 R15: 0000000000000201
 lock_sock include/net/sock.h:1624 [inline]
 dccp_sendmsg+0x3fe/0xb90 net/dccp/proto.c:765
 sock_sendmsg_nosec net/socket.c:718 [inline]
 __sock_sendmsg+0x1a6/0x270 net/socket.c:733
 ____sys_sendmsg+0x53a/0x860 net/socket.c:2573
 ___sys_sendmsg net/socket.c:2627 [inline]
 __sys_sendmmsg+0x36a/0x720 net/socket.c:2716
 __do_sys_sendmmsg net/socket.c:2743 [inline]
 __se_sys_sendmmsg net/socket.c:2740 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2740
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f4f2e87c8c9
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 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f4f2f57c0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f4f2e99bf80 RCX: 00007f4f2e87c8c9
RDX: 000000000000ffc3 RSI: 0000000020001e80 RDI: 0000000000000006
RBP: 00007f4f2e8d8ae8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f4f2e99bf80 R15: 00007ffea430c6f8
 </TASK>
Negotiation of local Allow Short Seqnos failed in state CHANGING at net/dccp/feat.c:1541/dccp_feat_activate_values()
----------------
Code disassembly (best guess):
   0:	8c e8                	mov    %gs,%eax
   2:	74 6f                	je     0x73
   4:	7d 0a                	jge    0x10
   6:	65 66 8b 05 04 98 80 	mov    %gs:0x7e809804(%rip),%ax        # 0x7e809812
   d:	7e
   e:	66 85 c0             	test   %ax,%ax
  11:	75 5d                	jne    0x70
  13:	bf 01 00 00 00       	mov    $0x1,%edi
  18:	e8 7d 25 0c 00       	call   0xc259a
  1d:	e8 a8 4e 46 00       	call   0x464eca
  22:	fb                   	sti
  23:	65 8b 05 c8 97 80 7e 	mov    %gs:0x7e8097c8(%rip),%eax        # 0x7e8097f2
* 2a:	85 c0                	test   %eax,%eax <-- trapping instruction
  2c:	75 05                	jne    0x33
  2e:	e8 57 01 a7 ff       	call   0xffa7018a
  33:	48 c7 44 24 20 0e 36 	movq   $0x45e0360e,0x20(%rsp)
  3a:	e0 45
  3c:	49                   	rex.WB
  3d:	c7                   	.byte 0xc7
  3e:	04 1c                	add    $0x1c,%al