general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 0 PID: 20726 Comm: syz-executor.2 Not tainted 6.7.0-rc5-syzkaller-00270-g0e389834672c #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 11/17/2023
RIP: 0010:ccid_hc_tx_send_packet net/dccp/ccid.h:166 [inline]
RIP: 0010:dccp_write_xmit+0x6f/0x220 net/dccp/output.c:356
Code: 03 48 89 44 24 08 4c 89 2c 24 48 8b 44 24 08 80 3c 28 00 74 08 48 89 df e8 6e ff 98 f7 49 89 df 48 8b 1b 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 53 ff 98 f7 48 8b 1b b8 b0 00 00 00
RSP: 0018:ffffc900051f7758 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888022c1ac80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888020449ec0
RBP: dffffc0000000000 R08: ffffffff8a526d71 R09: 1ffffffff21bae83
R10: dffffc0000000000 R11: fffffbfff21bae84 R12: ffff888022c1ac80
R13: ffff888020449ec0 R14: ffff88802044a810 R15: ffff88802044a7b0
FS:  00007f2d1effe6c0(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555556f5a938 CR3: 0000000027468000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 dccp_sendmsg+0x759/0xb70 net/dccp/proto.c:801
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 ____sys_sendmsg+0x592/0x890 net/socket.c:2584
 ___sys_sendmsg net/socket.c:2638 [inline]
 __sys_sendmmsg+0x3b2/0x730 net/socket.c:2724
 __do_sys_sendmmsg net/socket.c:2753 [inline]
 __se_sys_sendmmsg net/socket.c:2750 [inline]
 __x64_sys_sendmmsg+0xa0/0xb0 net/socket.c:2750
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0x45/0x110 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x63/0x6b
RIP: 0033:0x7f2d2047cba9
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 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:00007f2d1effe0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f2d2059bf80 RCX: 00007f2d2047cba9
RDX: 0000000000000008 RSI: 00000000200084c0 RDI: 0000000000000004
RBP: 00007f2d204c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000080 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007f2d2059bf80 R15: 00007ffc6fa54848
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:ccid_hc_tx_send_packet net/dccp/ccid.h:166 [inline]
RIP: 0010:dccp_write_xmit+0x6f/0x220 net/dccp/output.c:356
Code: 03 48 89 44 24 08 4c 89 2c 24 48 8b 44 24 08 80 3c 28 00 74 08 48 89 df e8 6e ff 98 f7 49 89 df 48 8b 1b 48 89 d8 48 c1 e8 03 <80> 3c 28 00 74 08 48 89 df e8 53 ff 98 f7 48 8b 1b b8 b0 00 00 00
RSP: 0018:ffffc900051f7758 EFLAGS: 00010246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff888022c1ac80
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff888020449ec0
RBP: dffffc0000000000 R08: ffffffff8a526d71 R09: 1ffffffff21bae83
R10: dffffc0000000000 R11: fffffbfff21bae84 R12: ffff888022c1ac80
R13: ffff888020449ec0 R14: ffff88802044a810 R15: ffff88802044a7b0
FS:  00007f2d1effe6c0(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00000000203c1000 CR3: 0000000027468000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	03 48 89             	add    -0x77(%rax),%ecx
   3:	44 24 08             	rex.R and $0x8,%al
   6:	4c 89 2c 24          	mov    %r13,(%rsp)
   a:	48 8b 44 24 08       	mov    0x8(%rsp),%rax
   f:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1)
  13:	74 08                	je     0x1d
  15:	48 89 df             	mov    %rbx,%rdi
  18:	e8 6e ff 98 f7       	call   0xf798ff8b
  1d:	49 89 df             	mov    %rbx,%r15
  20:	48 8b 1b             	mov    (%rbx),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	80 3c 28 00          	cmpb   $0x0,(%rax,%rbp,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	48 89 df             	mov    %rbx,%rdi
  33:	e8 53 ff 98 f7       	call   0xf798ff8b
  38:	48 8b 1b             	mov    (%rbx),%rbx
  3b:	b8 b0 00 00 00       	mov    $0xb0,%eax