KASAN: global-out-of-bounds Read in load_next_firmware_from_table

KASAN: global-out-of-bounds Read in load_next_firmware_from_table

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    7829a896 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan.git usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=12fd0e9ba00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=f6d4561982f71f63
dashboard link: https://syzkaller.appspot.com/bug?extid=98156c174c5a2cad9f8f
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=125f669ba00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=146b806ba00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+98156c174c5a2cad9f8f@syzkaller.appspotmail.com

usb 1-1: Direct firmware load for libertas/usb8388_v5.bin failed with error  
-2
usb 1-1: Direct firmware load for libertas/usb8388.bin failed with error -2
usb 1-1: Direct firmware load for usb8388.bin failed with error -2
==================================================================
BUG: KASAN: global-out-of-bounds in  
load_next_firmware_from_table+0x267/0x2d0  
drivers/net/wireless/marvell/libertas/firmware.c:99
Read of size 8 at addr ffffffff860942b8 by task kworker/1:1/21

CPU: 1 PID: 21 Comm: kworker/1:1 Not tainted 5.2.0-rc6+ #13
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events request_firmware_work_func
Call Trace:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0xca/0x13e lib/dump_stack.c:113
  print_address_description+0x67/0x231 mm/kasan/report.c:188
  __kasan_report.cold+0x1a/0x32 mm/kasan/report.c:317
  kasan_report+0xe/0x20 mm/kasan/common.c:614
  load_next_firmware_from_table+0x267/0x2d0  
drivers/net/wireless/marvell/libertas/firmware.c:99
  helper_firmware_cb+0xdc/0x100  
drivers/net/wireless/marvell/libertas/firmware.c:70
  request_firmware_work_func+0x126/0x242  
drivers/base/firmware_loader/main.c:785
  process_one_work+0x905/0x1570 kernel/workqueue.c:2269
  worker_thread+0x96/0xe20 kernel/workqueue.c:2415
  kthread+0x30b/0x410 kernel/kthread.c:255
  ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352

The buggy address belongs to the variable:
  fw_table+0x98/0x5c0

Memory state around the buggy address:
  ffffffff86094180: fa fa fa fa 00 04 fa fa fa fa fa fa 00 00 05 fa
  ffffffff86094200: fa fa fa fa 00 00 00 00 00 00 00 00 00 00 00 00
> ffffffff86094280: 00 00 00 00 00 00 fa fa fa fa fa fa 00 00 00 00
                                         ^
  ffffffff86094300: 00 00 00 01 fa fa fa fa 00 00 00 00 02 fa fa fa
  ffffffff86094380: fa fa fa fa 00 03 fa fa fa fa fa fa 00 00 00 00
==================================================================


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