WARNING in dummy_free_request

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    7f0cd6c7 usb: gadget: add raw-gadget interface
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=17b58e5ee00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f10b12ae04e03319
dashboard link: https://syzkaller.appspot.com/bug?extid=55ae006e0a1feae5aeab
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)

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

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+55ae006e0a1feae5aeab@xxxxxxxxxxxxxxxxxxxxxxxxx

------------[ cut here ]------------
WARNING: CPU: 1 PID: 19332 at drivers/usb/gadget/udc/dummy_hcd.c:679 dummy_free_request+0x6c/0x80 drivers/usb/gadget/udc/dummy_hcd.c:679
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 19332 Comm: syz-executor.5 Not tainted 5.6.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xef/0x16e lib/dump_stack.c:118
 panic+0x2aa/0x6e1 kernel/panic.c:221
 __warn.cold+0x2f/0x30 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027
RIP: 0010:dummy_free_request+0x6c/0x80 drivers/usb/gadget/udc/dummy_hcd.c:679
Code: c5 75 22 e8 26 06 96 fd 48 89 ef e8 3e 54 be fd 5b 5d e9 17 06 96 fd e8 12 06 96 fd 0f 0b 5b 5d e9 09 06 96 fd e8 04 06 96 fd <0f> 0b eb d5 48 89 ef e8 08 ae be fd eb c2 66 0f 1f 44 00 00 41 56
RSP: 0018:ffff8881c9eafdd8 EFLAGS: 00010016
RAX: 0000000000040000 RBX: ffff8881d0d5aa10 RCX: ffffc900012a0000
RDX: 000000000000012f RSI: ffffffff83a95c1c RDI: ffff8881d4d501c8
RBP: ffff8881d0d5aa00 R08: ffff8881d0f9b100 R09: ffffed103b666a84
R10: ffffed103b666a83 R11: ffff8881db33541b R12: 0000000000000212
R13: ffff8881ca832008 R14: 0000000000000000 R15: ffff8881ca832180
 raw_ioctl_ep_disable drivers/usb/gadget/legacy/raw_gadget.c:814 [inline]
 raw_ioctl+0x1281/0x19e0 drivers/usb/gadget/legacy/raw_gadget.c:1031
 vfs_ioctl fs/ioctl.c:47 [inline]
 ksys_ioctl+0x11a/0x180 fs/ioctl.c:763
 __do_sys_ioctl fs/ioctl.c:772 [inline]
 __se_sys_ioctl fs/ioctl.c:770 [inline]
 __x64_sys_ioctl+0x6f/0xb0 fs/ioctl.c:770
 do_syscall_64+0xb6/0x5a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45c537
Code: 48 83 c4 08 48 89 d8 5b 5d c3 66 0f 1f 84 00 00 00 00 00 48 89 e8 48 f7 d8 48 39 c3 0f 92 c0 eb 92 66 90 b8 10 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 0d b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5040518388 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 000000000045c537
RDX: 0000000000000000 RSI: 0000000040045506 RDI: 0000000000000006
RBP: 0000000000000006 R08: 0000000000405f0f R09: 0000000000000001
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000c80508
R13: 00000000000004e8 R14: 0000000000000002 R15: 0000000000000000
Shutting down cpus with NMI
Kernel Offset: disabled
Rebooting in 86400 seconds..


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