------------[ cut here ]------------
ret
WARNING: drivers/base/firmware_loader/fallback.c:148 at fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:148 [inline], CPU#3: cxacru/6050
WARNING: drivers/base/firmware_loader/fallback.c:148 at firmware_fallback_sysfs+0x6d5/0xc20 drivers/base/firmware_loader/fallback.c:238, CPU#3: cxacru/6050
Modules linked in:
CPU: 3 UID: 0 PID: 6050 Comm: cxacru 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:fw_load_from_user_helper drivers/base/firmware_loader/fallback.c:148 [inline]
RIP: 0010:firmware_fallback_sysfs+0x6d5/0xc20 drivers/base/firmware_loader/fallback.c:238
Code: ff ff e9 57 07 dd fa e8 f9 1b a7 fb e8 64 0e 6b fb 31 ff 89 c3 89 c6 e8 59 16 a7 fb 85 db 0f 84 0f fb ff ff e8 dc 1b a7 fb 90 <0f> 0b 90 48 8b 3c 24 4c 89 e2 48 c7 c6 a0 fb 71 8c e8 35 d6 dc fa
RSP: 0018:ffffc900058cfac0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 00000000fffffff5 RCX: ffffffff866348f7
RDX: ffff88802f7bca80 RSI: ffffffff86634904 RDI: ffff88802f7bca80
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 00000000fffffff5 R11: 0000000000000000 R12: ffffc900058cfcb0
R13: ffff888023d33940 R14: 0000000000001770 R15: ffff888023d33950
FS:  0000000000000000(0000) GS:ffff8880d60d8000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f62829eb700 CR3: 0000000050c9e000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 _request_firmware+0xfd7/0x13c0 drivers/base/firmware_loader/main.c:898
 request_firmware+0x35/0x50 drivers/base/firmware_loader/main.c:948
 cxacru_find_firmware.isra.0+0xc9/0x220 drivers/usb/atm/cxacru.c:994
 cxacru_heavy_init+0x194/0x4a0 drivers/usb/atm/cxacru.c:1016
 usbatm_do_heavy_init+0x97/0x140 drivers/usb/atm/usbatm.c:963
 kthread+0x370/0x450 kernel/kthread.c:436
 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>