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

[Andrey Konovalov]

On Tue, Oct 1, 2019 at 12:39 AM syzbot
<syzbot+3930f3e416920885c9d4@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit:    2994c077 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=104c47bd600000
> kernel config:  https://syzkaller.appspot.com/x/.config?x=69ddefac6929256a
> dashboard link: https://syzkaller.appspot.com/bug?extid=3930f3e416920885c9d4
> compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
>
> Unfortunately, I don't have any reproducer for this crash yet.
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: syzbot+3930f3e416920885c9d4@xxxxxxxxxxxxxxxxxxxxxxxxx
>
>   kthread+0x318/0x420 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> hso 2-1:0.9: Failed to find BULK IN ep
> ==================================================================
> BUG: KASAN: use-after-free in __mutex_lock_common
> kernel/locking/mutex.c:938 [inline]
> BUG: KASAN: use-after-free in __mutex_lock+0xf23/0x1360
> kernel/locking/mutex.c:1103
> Read of size 8 at addr ffff8881c73389d8 by task kworker/0:4/2784
>
> CPU: 0 PID: 2784 Comm: kworker/0:4 Not tainted 5.3.0+ #0
> 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.constprop.0+0x36/0x50 mm/kasan/report.c:374
>   __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:506
>   kasan_report+0xe/0x12 mm/kasan/common.c:634
>   __mutex_lock_common kernel/locking/mutex.c:938 [inline]
>   __mutex_lock+0xf23/0x1360 kernel/locking/mutex.c:1103
>   device_lock include/linux/device.h:1462 [inline]
>   device_del+0x9e/0xb10 drivers/base/core.c:2341
>   device_unregister drivers/base/core.c:2407 [inline]
>   device_destroy+0x96/0xe0 drivers/base/core.c:2986
>   tty_unregister_device+0x7e/0x1a0 drivers/tty/tty_io.c:3185
>   hso_serial_tty_unregister drivers/net/usb/hso.c:2231 [inline]
>   hso_create_bulk_serial_device drivers/net/usb/hso.c:2668 [inline]
>   hso_probe.cold+0xc8/0x121 drivers/net/usb/hso.c:2934
>   usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
>   usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_new_device.cold+0x6a4/0xe79 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+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
>   process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
>   worker_thread+0x96/0xe20 kernel/workqueue.c:2415
>   kthread+0x318/0x420 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> Allocated by task 2830:
>   save_stack+0x1b/0x80 mm/kasan/common.c:69
>   set_track mm/kasan/common.c:77 [inline]
>   __kasan_kmalloc mm/kasan/common.c:510 [inline]
>   __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:483
>   kmalloc include/linux/slab.h:552 [inline]
>   kzalloc include/linux/slab.h:686 [inline]
>   tty_register_device_attr+0x1b6/0x6f0 drivers/tty/tty_io.c:3124
>   hso_serial_common_create+0x113/0x710 drivers/net/usb/hso.c:2265
>   hso_create_bulk_serial_device drivers/net/usb/hso.c:2638 [inline]
>   hso_probe+0xc93/0x1a46 drivers/net/usb/hso.c:2934
>   usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
>   usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_new_device.cold+0x6a4/0xe79 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+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
>   process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
>   worker_thread+0x96/0xe20 kernel/workqueue.c:2415
>   kthread+0x318/0x420 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> Freed by task 2830:
>   save_stack+0x1b/0x80 mm/kasan/common.c:69
>   set_track mm/kasan/common.c:77 [inline]
>   kasan_set_free_info mm/kasan/common.c:332 [inline]
>   __kasan_slab_free+0x130/0x180 mm/kasan/common.c:471
>   slab_free_hook mm/slub.c:1424 [inline]
>   slab_free_freelist_hook mm/slub.c:1475 [inline]
>   slab_free mm/slub.c:3018 [inline]
>   kfree+0xe4/0x2f0 mm/slub.c:3959
>   device_release+0x71/0x200 drivers/base/core.c:1100
>   kobject_cleanup lib/kobject.c:693 [inline]
>   kobject_release lib/kobject.c:722 [inline]
>   kref_put include/linux/kref.h:65 [inline]
>   kobject_put+0x171/0x280 lib/kobject.c:739
>   put_device drivers/base/core.c:2300 [inline]
>   device_unregister drivers/base/core.c:2408 [inline]
>   device_destroy+0x9e/0xe0 drivers/base/core.c:2986
>   tty_unregister_device+0x7e/0x1a0 drivers/tty/tty_io.c:3185
>   hso_serial_tty_unregister drivers/net/usb/hso.c:2231 [inline]
>   hso_create_bulk_serial_device drivers/net/usb/hso.c:2668 [inline]
>   hso_probe.cold+0xc8/0x121 drivers/net/usb/hso.c:2934
>   usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
>   generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
>   usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
>   really_probe+0x281/0x6d0 drivers/base/dd.c:548
>   driver_probe_device+0x104/0x210 drivers/base/dd.c:721
>   __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
>   bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
>   __device_attach+0x217/0x360 drivers/base/dd.c:894
>   bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
>   device_add+0xae6/0x16f0 drivers/base/core.c:2201
>   usb_new_device.cold+0x6a4/0xe79 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+0x1b5c/0x3640 drivers/usb/core/hub.c:5441
>   process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
>   worker_thread+0x96/0xe20 kernel/workqueue.c:2415
>   kthread+0x318/0x420 kernel/kthread.c:255
>   ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> The buggy address belongs to the object at ffff8881c7338880
>   which belongs to the cache kmalloc-2k of size 2048
> The buggy address is located 344 bytes inside of
>   2048-byte region [ffff8881c7338880, ffff8881c7339080)
> The buggy address belongs to the page:
> page:ffffea00071cce00 refcount:1 mapcount:0 mapping:ffff8881da00c000
> index:0x0 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 0000000000000000 0000000100000001 ffff8881da00c000
> raw: 0000000000000000 00000000000f000f 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
>   ffff8881c7338880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881c7338900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8881c7338980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>                                                      ^
>   ffff8881c7338a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>   ffff8881c7338a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ==================================================================
>
>
> ---
> 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@xxxxxxxxxxxxxxxxx
>
> syzbot will keep track of this bug report. See:
> https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

Most likely the same issue as:

#syz dup: WARNING in hso_probe

https://syzkaller.appspot.com/bug?id=d3a08ccf68916f3b12821b5267b3e763244685af