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

From: Andrey Konovalov
Date: Mon Aug 19 2019 - 14:37:40 EST


On Mon, Jun 3, 2019 at 1:41 PM syzbot
<syzbot+93f2f45b19519b289613@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote:
>
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: 69bbe8c7 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=1684d87ca00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=193d8457178b3229
> dashboard link: https://syzkaller.appspot.com/bug?extid=93f2f45b19519b289613
> 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+93f2f45b19519b289613@xxxxxxxxxxxxxxxxxxxxxxxxx
>
> worker_thread+0x96/0xe20 kernel/workqueue.c:2414
> kthread+0x30b/0x410 kernel/kthread.c:254
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
> hso 3-1:0.2: Failed to find BULK IN ep
> ==================================================================
> BUG: KASAN: use-after-free in __lock_acquire+0x3a5d/0x5340
> kernel/locking/lockdep.c:3664
> Read of size 8 at addr ffff8881d98a4d60 by task kworker/0:0/5
>
> CPU: 0 PID: 5 Comm: kworker/0:0 Not tainted 5.2.0-rc1+ #10
> 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:3664
> lock_acquire+0x100/0x2b0 kernel/locking/lockdep.c:4302
> __mutex_lock_common kernel/locking/mutex.c:925 [inline]
> __mutex_lock+0xf9/0x12b0 kernel/locking/mutex.c:1072
> device_lock include/linux/device.h:1207 [inline]
> device_del+0xa2/0xb80 drivers/base/core.c:2240
> device_unregister drivers/base/core.c:2306 [inline]
> device_destroy+0x90/0xd0 drivers/base/core.c:2864
> tty_unregister_device+0x7e/0x1a0 drivers/tty/tty_io.c:3189
> hso_serial_tty_unregister drivers/net/usb/hso.c:2245 [inline]
> hso_create_bulk_serial_device drivers/net/usb/hso.c:2682 [inline]
> hso_probe.cold+0xc8/0x120 drivers/net/usb/hso.c:2948
> usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
> 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_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+0x281/0x660 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+0x8c1/0x1016 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+0x1ada/0x3590 drivers/usb/core/hub.c:5432
> process_one_work+0x905/0x1570 kernel/workqueue.c:2268
> worker_thread+0x96/0xe20 kernel/workqueue.c:2414
> kthread+0x30b/0x410 kernel/kthread.c:254
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> Allocated by task 3910:
> 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]
> tty_register_device_attr+0x1b6/0x6f0 drivers/tty/tty_io.c:3128
> hso_serial_common_create+0x113/0x710 drivers/net/usb/hso.c:2279
> hso_create_bulk_serial_device drivers/net/usb/hso.c:2652 [inline]
> hso_probe+0xc93/0x1a46 drivers/net/usb/hso.c:2948
> usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
> 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_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+0x281/0x660 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+0x8c1/0x1016 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+0x1ada/0x3590 drivers/usb/core/hub.c:5432
> process_one_work+0x905/0x1570 kernel/workqueue.c:2268
> process_scheduled_works kernel/workqueue.c:2330 [inline]
> worker_thread+0x7ab/0xe20 kernel/workqueue.c:2416
> kthread+0x30b/0x410 kernel/kthread.c:254
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> Freed by task 3910:
> 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:67 [inline]
> kobject_put+0x171/0x280 lib/kobject.c:737
> put_device drivers/base/core.c:2210 [inline]
> device_unregister drivers/base/core.c:2307 [inline]
> device_destroy+0x98/0xd0 drivers/base/core.c:2864
> tty_unregister_device+0x7e/0x1a0 drivers/tty/tty_io.c:3189
> hso_serial_tty_unregister drivers/net/usb/hso.c:2245 [inline]
> hso_create_bulk_serial_device drivers/net/usb/hso.c:2682 [inline]
> hso_probe.cold+0xc8/0x120 drivers/net/usb/hso.c:2948
> usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
> 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_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+0x281/0x660 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+0x8c1/0x1016 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+0x1ada/0x3590 drivers/usb/core/hub.c:5432
> process_one_work+0x905/0x1570 kernel/workqueue.c:2268
> process_scheduled_works kernel/workqueue.c:2330 [inline]
> worker_thread+0x7ab/0xe20 kernel/workqueue.c:2416
> kthread+0x30b/0x410 kernel/kthread.c:254
> ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
>
> The buggy address belongs to the object at ffff8881d98a4c80
> which belongs to the cache kmalloc-2k of size 2048
> The buggy address is located 224 bytes inside of
> 2048-byte region [ffff8881d98a4c80, ffff8881d98a5480)
> The buggy address belongs to the page:
> page:ffffea0007662800 refcount:1 mapcount:0 mapping:ffff8881dac02800
> index:0x0 compound_mapcount: 0
> flags: 0x200000000010200(slab|head)
> raw: 0200000000010200 dead000000000100 dead000000000200 ffff8881dac02800
> raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
> page dumped because: kasan: bad access detected
>
> Memory state around the buggy address:
> ffff8881d98a4c00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
> ffff8881d98a4c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ffff8881d98a4d00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ^
> ffff8881d98a4d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff8881d98a4e00: 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.

#syz dup: general protection fault in cdev_del