general protection fault in flexcop_usb_probe

From: syzbot <syzbot+d93dff37e6a89431c158@syzkaller.appspotmail.com>
To: andreyknvl@google.com, linux-kernel@vger.kernel.org,
	linux-media@vger.kernel.org, linux-usb@vger.kernel.org,
	mchehab@kernel.org, syzkaller-bugs@googlegroups.com
Subject: general protection fault in flexcop_usb_probe
Date: Fri, 12 Apr 2019 04:16:10 -0700	[thread overview]
Message-ID: <00000000000010fe260586536e86@google.com> (raw)

Hello,

syzbot found the following crash on:

HEAD commit:    9a33b369 usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan/tree/usb-fuzzer
console output: https://syzkaller.appspot.com/x/log.txt?x=15adefa7200000
kernel config:  https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15
dashboard link: https://syzkaller.appspot.com/bug?extid=d93dff37e6a89431c158
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=175c0cd3200000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=1186469f200000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+d93dff37e6a89431c158@syzkaller.appspotmail.com

b2c2-flexcop: found 'LG Electronics LGDT3303 VSB/QAM Frontend' .
usb 1-1: DVB: registering adapter 0 frontend 0 (LG Electronics LGDT3303  
VSB/QAM Frontend)...
b2c2-flexcop: initialization of 'Air2PC/AirStar 2 ATSC 3rd generation  
(HD5000)' at the 'USB' bus controlled by a 'FlexCopIII' complete
kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 21 Comm: kworker/1:1 Not tainted 5.1.0-rc4-319354-g9a33b36 #3
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:flexcop_usb_transfer_init  
drivers/media/usb/b2c2/flexcop-usb.c:429 [inline]
RIP: 0010:flexcop_usb_probe.cold+0x1cb/0x7bd  
drivers/media/usb/b2c2/flexcop-usb.c:574
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 74 05 e8 dc d2 65 f7 48 8b 5b 18 b8  
ff ff 37 00 48 c1 e0 2a 48 8d 7b 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48  
89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 c1
RSP: 0018:ffff8880a862f2e0 EFLAGS: 00010247
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8a430240
RDX: 0000000000000000 RSI: ffffffff8a430300 RDI: 0000000000000004
RBP: ffff88809d3b9108 R08: ffff8880a84d4980 R09: ffffed1015a24fc9
R10: ffffed1015a24fc8 R11: ffff8880ad127e47 R12: ffff88809d3b9148
R13: 0000000000000000 R14: ffff88809d3b9100 R15: ffff88809575c000
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd361552000 CR3: 0000000095f74000 CR4: 00000000001406e0
Call Trace:
  usb_probe_interface+0x31d/0x820 drivers/usb/core/driver.c:361
  really_probe+0x2da/0xb10 drivers/base/dd.c:509
  driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
  __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
  bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
  __device_attach+0x223/0x3a0 drivers/base/dd.c:844
  bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
  device_add+0xad2/0x16e0 drivers/base/core.c:2106
  usb_set_configuration+0xdf7/0x1740 drivers/usb/core/message.c:2021
  generic_probe+0xa2/0xda drivers/usb/core/generic.c:210
  usb_probe_device+0xc0/0x150 drivers/usb/core/driver.c:266
  really_probe+0x2da/0xb10 drivers/base/dd.c:509
  driver_probe_device+0x21d/0x350 drivers/base/dd.c:671
  __device_attach_driver+0x1d8/0x290 drivers/base/dd.c:778
  bus_for_each_drv+0x163/0x1e0 drivers/base/bus.c:454
  __device_attach+0x223/0x3a0 drivers/base/dd.c:844
  bus_probe_device+0x1f1/0x2a0 drivers/base/bus.c:514
  device_add+0xad2/0x16e0 drivers/base/core.c:2106
  usb_new_device.cold+0x537/0xccf drivers/usb/core/hub.c:2534
  hub_port_connect drivers/usb/core/hub.c:5089 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
  port_event drivers/usb/core/hub.c:5350 [inline]
  hub_event+0x138e/0x3b00 drivers/usb/core/hub.c:5432
  process_one_work+0x90f/0x1580 kernel/workqueue.c:2269
  worker_thread+0x9b/0xe20 kernel/workqueue.c:2415
  kthread+0x313/0x420 kernel/kthread.c:253
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 8800fc602d77e417 ]---
RIP: 0010:flexcop_usb_transfer_init  
drivers/media/usb/b2c2/flexcop-usb.c:429 [inline]
RIP: 0010:flexcop_usb_probe.cold+0x1cb/0x7bd  
drivers/media/usb/b2c2/flexcop-usb.c:574
Code: 48 89 fa 48 c1 ea 03 80 3c 02 00 74 05 e8 dc d2 65 f7 48 8b 5b 18 b8  
ff ff 37 00 48 c1 e0 2a 48 8d 7b 04 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48  
89 f8 83 e0 07 83 c0 01 38 d0 7c 08 84 d2 0f 85 c1
RSP: 0018:ffff8880a862f2e0 EFLAGS: 00010247
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8a430240
RDX: 0000000000000000 RSI: ffffffff8a430300 RDI: 0000000000000004
RBP: ffff88809d3b9108 R08: ffff8880a84d4980 R09: ffffed1015a24fc9
R10: ffffed1015a24fc8 R11: ffff8880ad127e47 R12: ffff88809d3b9148
R13: 0000000000000000 R14: ffff88809d3b9100 R15: ffff88809575c000
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd361552000 CR3: 0000000095f74000 CR4: 00000000001406e0

---
This bug is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzkaller@googlegroups.com.

syzbot will keep track of this bug report. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.
syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches