cxacru 5-1:1.0: receive of cm 0x85 failed (-104)
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017]
CPU: 0 UID: 0 PID: 5319 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:adsl_state_store+0x5cc/0x770 drivers/usb/atm/cxacru.c:359
Code: 03 42 80 3c 28 00 74 14 48 89 4c 24 10 48 8b 7c 24 10 e8 f7 7e 85 fa 48 8b 4c 24 10 48 8b 11 48 83 c2 10 48 89 d0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 4b 01 00 00 4d 89 f4 8b 32 48 c7 c7 60
RSP: 0018:ffffc9000e13fb80 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 00000000ffffff98 RCX: ffff88803b930078
RDX: 0000000000000010 RSI: 00000000000006bf RDI: 00000000000006c0
RBP: ffffc9000e13fc40 R08: ffffc9000e13f907 R09: 1ffff92001c27f20
R10: dffffc0000000000 R11: fffff52001c27f21 R12: ffff888043833800
R13: dffffc0000000000 R14: 0000000000000004 R15: 1ffff92001c27f74
FS:  00007fee9cb2e6c0(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555640b6a58 CR3: 00000000128de000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x612/0xba0 fs/read_write.c:687
 ksys_write+0x150/0x270 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fee9bb9e0d9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fee9cb2dfe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007fee9be26090 RCX: 00007fee9bb9e0d9
RDX: 0000000000000004 RSI: 0000200000001200 RDI: 000000000000000a
RBP: 00007fee9bc35024 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fee9be26128 R14: 00007fee9be26090 R15: 00007ffeac7af618
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:adsl_state_store+0x5cc/0x770 drivers/usb/atm/cxacru.c:359
Code: 03 42 80 3c 28 00 74 14 48 89 4c 24 10 48 8b 7c 24 10 e8 f7 7e 85 fa 48 8b 4c 24 10 48 8b 11 48 83 c2 10 48 89 d0 48 c1 e8 03 <42> 0f b6 04 28 84 c0 0f 85 4b 01 00 00 4d 89 f4 8b 32 48 c7 c7 60
RSP: 0018:ffffc9000e13fb80 EFLAGS: 00010202
RAX: 0000000000000002 RBX: 00000000ffffff98 RCX: ffff88803b930078
RDX: 0000000000000010 RSI: 00000000000006bf RDI: 00000000000006c0
RBP: ffffc9000e13fc40 R08: ffffc9000e13f907 R09: 1ffff92001c27f20
R10: dffffc0000000000 R11: fffff52001c27f21 R12: ffff888043833800
R13: dffffc0000000000 R14: 0000000000000004 R15: 1ffff92001c27f74
FS:  00007fee9cb2e6c0(0000) GS:ffff88808c30a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555640b6a58 CR3: 00000000128de000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	03 42 80             	add    -0x80(%rdx),%eax
   3:	3c 28                	cmp    $0x28,%al
   5:	00 74 14 48          	add    %dh,0x48(%rsp,%rdx,1)
   9:	89 4c 24 10          	mov    %ecx,0x10(%rsp)
   d:	48 8b 7c 24 10       	mov    0x10(%rsp),%rdi
  12:	e8 f7 7e 85 fa       	call   0xfa857f0e
  17:	48 8b 4c 24 10       	mov    0x10(%rsp),%rcx
  1c:	48 8b 11             	mov    (%rcx),%rdx
  1f:	48 83 c2 10          	add    $0x10,%rdx
  23:	48 89 d0             	mov    %rdx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 0f b6 04 28       	movzbl (%rax,%r13,1),%eax <-- trapping instruction
  2f:	84 c0                	test   %al,%al
  31:	0f 85 4b 01 00 00    	jne    0x182
  37:	4d 89 f4             	mov    %r14,%r12
  3a:	8b 32                	mov    (%rdx),%esi
  3c:	48                   	rex.W
  3d:	c7                   	.byte 0xc7
  3e:	c7                   	(bad)
  3f:	60                   	(bad)