dummy_hcd dummy_hcd.0: remove, state 4
usb usb5: USB disconnect, device number 1
dummy_hcd dummy_hcd.0: stopped
dummy_hcd dummy_hcd.0: USB bus 5 deregistered
gadgetfs: bound to dummy_udc driver
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 2 UID: 0 PID: 5933 Comm: syz.0.17 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:dummy_udc_start+0x91/0x1d0 drivers/usb/gadget/udc/dummy_hcd.c:1022
Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 28 01 00 00 4c 8b ab 90 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 10 01 00 00 83 ed 01 bf 02 00 00 00 49 8b 5d 00
RSP: 0018:ffffc90003b879b0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802bd1cc00 RCX: ffffffff87d0cf39
RDX: 0000000000000000 RSI: ffffffff87d0cf47 RDI: ffff88802bd1d290
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff90256060
R13: 0000000000000000 R14: ffff88802cf584f1 R15: ffff88802cf58008
FS:  000055555b0a9500(0000) GS:ffff8880d5fdc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33063fff CR3: 000000002d979000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 usb_gadget_udc_start_locked drivers/usb/gadget/udc/core.c:1237 [inline]
 gadget_bind_driver+0x4ac/0xbf0 drivers/usb/gadget/udc/core.c:1667
 call_driver_probe drivers/base/dd.c:628 [inline]
 really_probe+0x241/0xa60 drivers/base/dd.c:706
 __driver_probe_device+0x20e/0x450 drivers/base/dd.c:868
 driver_probe_device+0x4a/0x140 drivers/base/dd.c:898
 __driver_attach+0x21f/0x5b0 drivers/base/dd.c:1292
 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383
 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:763
 driver_register+0x1e2/0x360 drivers/base/driver.c:174
 usb_gadget_register_driver_owner+0x132/0x210 drivers/usb/gadget/udc/core.c:1752
 dev_config+0xdce/0x1610 drivers/usb/gadget/legacy/inode.c:1883
 vfs_write+0x2aa/0x1050 fs/read_write.c:685
 ksys_write+0x12a/0x250 fs/read_write.c:739
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f7e83d9de99
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:00007fff6757b308 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f7e84025fa0 RCX: 00007f7e83d9de99
RDX: 000000000000001f RSI: 0000200000000400 RDI: 0000000000000004
RBP: 00007f7e83e33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7e84025fac R14: 00007f7e84025fa0 R15: 00007f7e84025fa0
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:dummy_udc_start+0x91/0x1d0 drivers/usb/gadget/udc/dummy_hcd.c:1022
Code: df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 28 01 00 00 4c 8b ab 90 06 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ea 48 c1 ea 03 <80> 3c 02 00 0f 85 10 01 00 00 83 ed 01 bf 02 00 00 00 49 8b 5d 00
RSP: 0018:ffffc90003b879b0 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff88802bd1cc00 RCX: ffffffff87d0cf39
RDX: 0000000000000000 RSI: ffffffff87d0cf47 RDI: ffff88802bd1d290
RBP: 0000000000000002 R08: 0000000000000005 R09: 0000000000000005
R10: 0000000000000002 R11: 0000000000000000 R12: ffffffff90256060
R13: 0000000000000000 R14: ffff88802cf584f1 R15: ffff88802cf58008
FS:  000055555b0a9500(0000) GS:ffff8880d5fdc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33063fff CR3: 000000002d979000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess):
   0:	df 48 89             	fisttps -0x77(%rax)
   3:	fa                   	cli
   4:	48 c1 ea 03          	shr    $0x3,%rdx
   8:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1)
   c:	0f 85 28 01 00 00    	jne    0x13a
  12:	4c 8b ab 90 06 00 00 	mov    0x690(%rbx),%r13
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	4c 89 ea             	mov    %r13,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	0f 85 10 01 00 00    	jne    0x144
  34:	83 ed 01             	sub    $0x1,%ebp
  37:	bf 02 00 00 00       	mov    $0x2,%edi
  3c:	49 8b 5d 00          	mov    0x0(%r13),%rbx