------------[ cut here ]------------
!work->func
WARNING: kernel/workqueue.c:4335 at __flush_work+0xa5d/0xcb0 kernel/workqueue.c:4335, CPU#2: syz.6.4252/20021
Modules linked in:
CPU: 2 UID: 0 PID: 20021 Comm: syz.6.4252 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:__flush_work+0xa5d/0xcb0 kernel/workqueue.c:4335
Code: 35 00 00 00 00 e8 63 03 16 00 e8 5e 64 1f 00 c6 44 24 0f 00 e9 91 fd ff ff e8 7f 50 3a 00 90 0f 0b 90 eb eb e8 74 50 3a 00 90 <0f> 0b 90 eb e0 e8 69 50 3a 00 e8 64 50 3a 00 48 8b 3c 24 e8 5b 89
RSP: 0018:ffffc9000e6dfa68 EFLAGS: 00010283
RAX: 0000000000001092 RBX: dffffc0000000000 RCX: ffffc90028463000
RDX: 0000000000080000 RSI: ffffffff81cf7f2c RDI: ffff888021152540
RBP: ffff88806fa0c998 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88806fa0c9b0 R14: 0000000000000001 R15: 0000000000000001
FS:  0000000000000000(0000) GS:ffff888096df3000(0063) knlGS:00000000f4f58b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f4f57ff4 CR3: 0000000046827000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __cancel_work_sync kernel/workqueue.c:4494 [inline]
 cancel_work_sync+0xd1/0xf0 kernel/workqueue.c:4531
 f_midi_free+0xc7/0x140 drivers/usb/gadget/function/f_midi.c:1312
 usb_put_function+0x3e/0x50 drivers/usb/gadget/functions.c:87
 config_usb_cfg_unlink+0x29d/0x3e0 drivers/usb/gadget/configfs.c:508
 configfs_symlink+0xca1/0x11f0 fs/configfs/symlink.c:202
 vfs_symlink fs/namei.c:5660 [inline]
 vfs_symlink+0x178/0x4d0 fs/namei.c:5639
 filename_symlinkat+0x2a6/0x560 fs/namei.c:5685
 __do_sys_symlinkat fs/namei.c:5705 [inline]
 __se_sys_symlinkat fs/namei.c:5700 [inline]
 __ia32_sys_symlinkat+0x9b/0xe0 fs/namei.c:5700
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf6fcefec
Code: Unable to access opcode bytes at 0xf6fcefc2.
RSP: 002b:00000000f4f5850c EFLAGS: 00000292 ORIG_RAX: 0000000000000130
RAX: ffffffffffffffda RBX: 0000000080000580 RCX: 00000000ffffff9c
RDX: 00000000800005c0 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>