Re: general protection fault in sisusb_probe

[syzbot]

syzbot has found a reproducer for the following crash on:

HEAD commit:    43151d6c 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=1222d274a00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=4183eeef650d1234
dashboard link: https://syzkaller.appspot.com/bug?extid=a0cbdbd6d169020c8959
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1382e600a00000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=174783f0a00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+a0cbdbd6d169020c8959@xxxxxxxxxxxxxxxxxxxxxxxxx

 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
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: 17 Comm: kworker/1:0 Not tainted 5.1.0-rc3-319004-g43151d6 #6
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:dev_name include/linux/device.h:1087 [inline]
RIP: 0010:__dev_printk+0x3f/0x215 drivers/base/core.c:3208
Code: 89 f5 53 e8 8e 53 1c fc 48 85 ed 0f 84 c9 01 00 00 e8 80 53 1c fc 48  
8d 7d 50 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 <80> 3c 02 00 74  
05 e8 41 68 53 fc 4c 8b 7d 50 4d 85 ff 75 28 e8 53
RSP: 0018:ffff8880a84ff1c8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffed101509fe40 RCX: ffffffff8980f1cb
RDX: 000000000000001e RSI: ffffffff855576f0 RDI: 00000000000000f0
RBP: 00000000000000a0 R08: ffff8880a84db100 R09: 0000000000000006
R10: ffff8880a84dba08 R11: ffff8880a84db100 R12: ffffffff8f031080
R13: ffff8880a84ff220 R14: ffff888090615500 R15: ffff88808c860000
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa07b90000 CR3: 00000000a0896000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 _dev_err+0xdc/0x10e drivers/base/core.c:3251
 sisusb_probe+0x1c8/0xbd6 drivers/usb/misc/sisusbvga/sisusb.c:3035
 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:2023
 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 3af8db6f82d76f53 ]---
RIP: 0010:dev_name include/linux/device.h:1087 [inline]
RIP: 0010:__dev_printk+0x3f/0x215 drivers/base/core.c:3208
Code: 89 f5 53 e8 8e 53 1c fc 48 85 ed 0f 84 c9 01 00 00 e8 80 53 1c fc 48  
8d 7d 50 b8 ff ff 37 00 48 89 fa 48 c1 e0 2a 48 c1 ea 03 <80> 3c 02 00 74  
05 e8 41 68 53 fc 4c 8b 7d 50 4d 85 ff 75 28 e8 53
RSP: 0018:ffff8880a84ff1c8 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffed101509fe40 RCX: ffffffff8980f1cb
RDX: 000000000000001e RSI: ffffffff855576f0 RDI: 00000000000000f0
RBP: 00000000000000a0 R08: ffff8880a84db100 R09: 0000000000000006
R10: ffff8880a84dba08 R11: ffff8880a84db100 R12: ffffffff8f031080
R13: ffff8880a84ff220 R14: ffff888090615500 R15: ffff88808c860000
FS:  0000000000000000(0000) GS:ffff8880ad100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007faa07b90000 CR3: 00000000a0896000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400