syzbot

general protection fault, probably for non-canonical address 0xdffffc000000001b: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x00000000000000d8-0x00000000000000df]
CPU: 0 PID: 3610 Comm: syz-executor148 Tainted: G        W         5.17.0-syzkaller-04796-g169e77764adc #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:llc_ui_sendmsg+0x1ea/0x10d0 net/llc/af_llc.c:947
Code: 80 3c 02 00 0f 85 50 0d 00 00 4c 8b a5 38 05 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 de 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 33
RSP: 0018:ffffc90003a7f8c8 EFLAGS: 00010207
RAX: dffffc0000000000 RBX: ffffc90003a7fd70 RCX: 0000000000000000
RDX: 000000000000001b RSI: ffffffff875d3ec3 RDI: 00000000000000de
RBP: ffff8880123cc000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff875d3eb5 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880183eec18 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fb7c3b22700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020006038 CR3: 0000000072da0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 sock_sendmsg_nosec net/socket.c:705 [inline]
 sock_sendmsg+0xcf/0x120 net/socket.c:725
 ____sys_sendmsg+0x331/0x810 net/socket.c:2413
 ___sys_sendmsg+0xf3/0x170 net/socket.c:2467
 __sys_sendmmsg+0x195/0x470 net/socket.c:2553
 __do_sys_sendmmsg net/socket.c:2582 [inline]
 __se_sys_sendmmsg net/socket.c:2579 [inline]
 __x64_sys_sendmmsg+0x99/0x100 net/socket.c:2579
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x44/0xae
RIP: 0033:0x7fb7c3b91989
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 11 15 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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fb7c3b22318 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007fb7c3c193f8 RCX: 00007fb7c3b91989
RDX: 03fffffffffffeed RSI: 0000000020001380 RDI: 0000000000000003
RBP: 00007fb7c3c193f0 R08: 00007fb7c3b22700 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fb7c3c193fc
R13: 00007ffe7fb8beff R14: 00007fb7c3b22400 R15: 0000000000022000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:llc_ui_sendmsg+0x1ea/0x10d0 net/llc/af_llc.c:947
Code: 80 3c 02 00 0f 85 50 0d 00 00 4c 8b a5 38 05 00 00 48 b8 00 00 00 00 00 fc ff df 49 8d bc 24 de 00 00 00 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 33
RSP: 0018:ffffc90003a7f8c8 EFLAGS: 00010207

RAX: dffffc0000000000 RBX: ffffc90003a7fd70 RCX: 0000000000000000
RDX: 000000000000001b RSI: ffffffff875d3ec3 RDI: 00000000000000de
RBP: ffff8880123cc000 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff875d3eb5 R11: 0000000000000000 R12: 0000000000000000
R13: ffff8880183eec18 R14: 0000000000000000 R15: 0000000000000000
FS:  00007fb7c3b22700(0000) GS:ffff8880b9c00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6377c60310 CR3: 0000000072da0000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
----------------
Code disassembly (best guess):
   0:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   4:	0f 85 50 0d 00 00    	jne    0xd5a
   a:	4c 8b a5 38 05 00 00 	mov    0x538(%rbp),%r12
  11:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  18:	fc ff df
  1b:	49 8d bc 24 de 00 00 	lea    0xde(%r12),%rdi
  22:	00
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	0f b6 14 02          	movzbl (%rdx,%rax,1),%edx <-- trapping instruction
  2e:	48 89 f8             	mov    %rdi,%rax
  31:	83 e0 07             	and    $0x7,%eax
  34:	83 c0 01             	add    $0x1,%eax
  37:	38 d0                	cmp    %dl,%al
  39:	7c 08                	jl     0x43
  3b:	84 d2                	test   %dl,%dl
  3d:	0f                   	.byte 0xf
  3e:	85 33                	test   %esi,(%rbx)