[syzbot] [usb?] general protection fault in usb_gadget_udc_reset (4)

[syzbot <syzbot+19bed92c97bee999e5db@syzkaller.appspotmail.com>]

Hello,

syzbot found the following issue on:

HEAD commit:    566771afc7a8 Merge tag 'v6.18-rc2-smb-server-fixes' of git..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13956e7c580000
kernel config:  https://syzkaller.appspot.com/x/.config?x=8345ce4ce316ca28
dashboard link: https://syzkaller.appspot.com/bug?extid=19bed92c97bee999e5db
compiler:       Debian clang version 20.1.8 (++20250708063551+0c9f909b7976-1~exp1~20250708183702.136), Debian LLD 20.1.8

Unfortunately, I don't have any reproducer for this issue yet.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/52417ef1f782/disk-566771af.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/66730a263bf1/vmlinux-566771af.xz
kernel image: https://storage.googleapis.com/syzbot-assets/1fe0762efb1f/bzImage-566771af.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+19bed92c97bee999e5db@syzkaller.appspotmail.com

usb 1-1: new full-speed USB device number 6 using dummy_hcd
usb 1-1: unable to read config index 0 descriptor/all
usb 1-1: can't read configurations, error -110
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000008: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000040-0x0000000000000047]
CPU: 1 UID: 0 PID: 5869 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: usb_hub_wq hub_event
RIP: 0010:usb_gadget_udc_reset+0x27/0x60 drivers/usb/gadget/udc/core.c:1195
Code: 90 90 90 f3 0f 1e fa 41 56 53 49 89 f6 48 89 fb e8 3e 6b fb fa 49 83 c6 40 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 bb 22 5d fb 4d 8b 1e 48 89 df 2e 2e
RSP: 0018:ffffc900051b7260 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888143b54c40 RCX: dffffc0000000000
RDX: ffffc9001a01b000 RSI: 0000000000002b35 RDI: 0000000000002b36
RBP: ffff8880305aa66c R08: ffffffff8ed62877 R09: 1ffffffff1dac50e
R10: dffffc0000000000 R11: fffffbfff1dac50f R12: ffff888143b54c40
R13: 1ffff11004eceaa1 R14: 0000000000000040 R15: 1ffff1102876a987
FS:  0000000000000000(0000) GS:ffff888126efc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce4efb4f98 CR3: 000000004a02e000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 set_link_state+0x80b/0x1220 drivers/usb/gadget/udc/dummy_hcd.c:469
 dummy_hub_control+0xcc0/0x1760 drivers/usb/gadget/udc/dummy_hcd.c:2327
 rh_call_control drivers/usb/core/hcd.c:656 [inline]
 rh_urb_enqueue drivers/usb/core/hcd.c:821 [inline]
 usb_hcd_submit_urb+0xde9/0x1a80 drivers/usb/core/hcd.c:1542
 usb_start_wait_urb+0x114/0x4c0 drivers/usb/core/message.c:59
 usb_internal_control_msg drivers/usb/core/message.c:103 [inline]
 usb_control_msg+0x232/0x3e0 drivers/usb/core/message.c:154
 set_port_feature drivers/usb/core/hub.c:470 [inline]
 hub_port_reset+0x390/0x1740 drivers/usb/core/hub.c:3082
 hub_port_init+0x2b0/0x2800 drivers/usb/core/hub.c:4938
 hub_port_connect drivers/usb/core/hub.c:5495 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5706 [inline]
 port_event drivers/usb/core/hub.c:5870 [inline]
 hub_event+0x2532/0x4a20 drivers/usb/core/hub.c:5952
 process_one_work kernel/workqueue.c:3263 [inline]
 process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3346
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3427
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:usb_gadget_udc_reset+0x27/0x60 drivers/usb/gadget/udc/core.c:1195
Code: 90 90 90 f3 0f 1e fa 41 56 53 49 89 f6 48 89 fb e8 3e 6b fb fa 49 83 c6 40 4c 89 f0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 4c 89 f7 e8 bb 22 5d fb 4d 8b 1e 48 89 df 2e 2e
RSP: 0018:ffffc900051b7260 EFLAGS: 00010202
RAX: 0000000000000008 RBX: ffff888143b54c40 RCX: dffffc0000000000
RDX: ffffc9001a01b000 RSI: 0000000000002b35 RDI: 0000000000002b36
RBP: ffff8880305aa66c R08: ffffffff8ed62877 R09: 1ffffffff1dac50e
R10: dffffc0000000000 R11: fffffbfff1dac50f R12: ffff888143b54c40
R13: 1ffff11004eceaa1 R14: 0000000000000040 R15: 1ffff1102876a987
FS:  0000000000000000(0000) GS:ffff888126efc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fce4efb4f98 CR3: 000000004a02e000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	90                   	nop
   1:	90                   	nop
   2:	90                   	nop
   3:	f3 0f 1e fa          	endbr64
   7:	41 56                	push   %r14
   9:	53                   	push   %rbx
   a:	49 89 f6             	mov    %rsi,%r14
   d:	48 89 fb             	mov    %rdi,%rbx
  10:	e8 3e 6b fb fa       	call   0xfafb6b53
  15:	49 83 c6 40          	add    $0x40,%r14
  19:	4c 89 f0             	mov    %r14,%rax
  1c:	48 c1 e8 03          	shr    $0x3,%rax
  20:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
  27:	fc ff df
* 2a:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 bb 22 5d fb       	call   0xfb5d22f3
  38:	4d 8b 1e             	mov    (%r14),%r11
  3b:	48 89 df             	mov    %rbx,%rdi
  3e:	2e                   	cs
  3f:	2e                   	cs


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