Re: KASAN: use-after-free Read in device_release_driver_internal

[syzbot <syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com>]

Hello,

syzbot has tested the proposed patch but the reproducer still triggered  
crash:
KASAN: use-after-free Read in device_release_driver_internal

usb 4-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3a5d/0x5340  
kernel/locking/lockdep.c:3665
Read of size 8 at addr ffff8881d4a54510 by task kworker/0:3/2876

CPU: 0 PID: 2876 Comm: kworker/0:3 Not tainted 5.2.0-rc6+ #1
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
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
  __lock_acquire+0x3a5d/0x5340 kernel/locking/lockdep.c:3665
  lock_acquire+0x100/0x2b0 kernel/locking/lockdep.c:4303
  __mutex_lock_common kernel/locking/mutex.c:926 [inline]
  __mutex_lock+0xf9/0x12b0 kernel/locking/mutex.c:1073
  device_release_driver_internal+0x23/0x4c0 drivers/base/dd.c:1109
  bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
  device_del+0x460/0xb80 drivers/base/core.c:2274
  usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
  usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2199
  hub_port_connect drivers/usb/core/hub.c:4949 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x13bd/0x3550 drivers/usb/core/hub.c:5441
  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

Allocated by task 22:
  save_stack+0x1b/0x80 mm/kasan/common.c:71
  set_track mm/kasan/common.c:79 [inline]
  __kasan_kmalloc mm/kasan/common.c:489 [inline]
  __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:462
  kmalloc include/linux/slab.h:547 [inline]
  kzalloc include/linux/slab.h:742 [inline]
  usb_set_configuration+0x2c4/0x1670 drivers/usb/core/message.c:1846
  generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
  usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
  really_probe+0x281/0x660 drivers/base/dd.c:509
  driver_probe_device+0x104/0x210 drivers/base/dd.c:670
  __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:777
  bus_for_each_drv+0x15c/0x1e0 drivers/base/bus.c:454
  __device_attach+0x217/0x360 drivers/base/dd.c:843
  bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
  device_add+0xae6/0x16f0 drivers/base/core.c:2111
  usb_new_device.cold+0x6a4/0xe61 drivers/usb/core/hub.c:2536
  hub_port_connect drivers/usb/core/hub.c:5098 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x1abd/0x3550 drivers/usb/core/hub.c:5441
  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

Freed by task 2876:
  save_stack+0x1b/0x80 mm/kasan/common.c:71
  set_track mm/kasan/common.c:79 [inline]
  __kasan_slab_free+0x130/0x180 mm/kasan/common.c:451
  slab_free_hook mm/slub.c:1421 [inline]
  slab_free_freelist_hook mm/slub.c:1448 [inline]
  slab_free mm/slub.c:2994 [inline]
  kfree+0xd7/0x280 mm/slub.c:3949
  device_release+0x71/0x200 drivers/base/core.c:1064
  kobject_cleanup lib/kobject.c:691 [inline]
  kobject_release lib/kobject.c:720 [inline]
  kref_put include/linux/kref.h:65 [inline]
  kobject_put+0x171/0x280 lib/kobject.c:737
  put_device+0x1b/0x30 drivers/base/core.c:2210
  klist_put+0xce/0x170 lib/klist.c:221
  bus_remove_device+0x3a4/0x4a0 drivers/base/bus.c:552
  device_del+0x460/0xb80 drivers/base/core.c:2274
  usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
  usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2199
  hub_port_connect drivers/usb/core/hub.c:4949 [inline]
  hub_port_connect_change drivers/usb/core/hub.c:5213 [inline]
  port_event drivers/usb/core/hub.c:5359 [inline]
  hub_event+0x13bd/0x3550 drivers/usb/core/hub.c:5441
  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 object at ffff8881d4a54400
  which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 272 bytes inside of
  2048-byte region [ffff8881d4a54400, ffff8881d4a54c00)
The buggy address belongs to the page:
page:ffffea0007529400 refcount:1 mapcount:0 mapping:ffff8881dac02800  
index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 ffffea000753da00 0000000500000005 ffff8881dac02800
raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
  ffff8881d4a54400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881d4a54480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8881d4a54500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                          ^
  ffff8881d4a54580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
  ffff8881d4a54600: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================


Tested on:

commit:         6a3599ce usb-fuzzer: main usb gadget fuzzer driver
git tree:       https://github.com/google/kasan.git
console output: https://syzkaller.appspot.com/x/log.txt?x=132aca2c600000
kernel config:  https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)