usb/serial: use-after-free in usb_serial_disconnect/__lock_acquire

[Andrey Konovalov]

Hi!

I've got the following report while fuzzing the kernel with syzkaller.

On commit e19b205be43d11bff638cad4487008c48d21c103 (4.14-rc2).

gadgetfs: bound to dummy_udc driver
usb 1-1: new full-speed USB device number 2 using dummy_hcd
gadgetfs: connected
gadgetfs: disconnected
gadgetfs: connected
usb 1-1: config 4 has an invalid interface number: 1 but max is 0
usb 1-1: config 4 has an invalid interface number: 153 but max is 0
usb 1-1: config 4 has 2 interfaces, different from the descriptor's value: 1
usb 1-1: config 4 has no interface number 0
usb 1-1: config 4 interface 1 altsetting 255 has an invalid endpoint
with address 0x0, skipping
usb 1-1: config 4 interface 1 altsetting 255 has an invalid endpoint
with address 0xFF, skipping
usb 1-1: config 4 interface 1 altsetting 255 has an invalid endpoint
with address 0x56, skipping
usb 1-1: too many endpoints for config 4 interface 153 altsetting 67:
174, using maximum allowed: 30
usb 1-1: config 4 interface 153 altsetting 67 has 0 endpoint
descriptors, different from the interface d
escriptor's value: 174
usb 1-1: config 4 interface 1 has no altsetting 0
usb 1-1: config 4 interface 153 has no altsetting 0
usb 1-1: New USB device found, idVendor=1199, idProduct=6832
usb 1-1: New USB device strings: Mfr=4, Product=20, SerialNumber=3
usb 1-1: Product: a
usb 1-1: Manufacturer: a
usb 1-1: SerialNumber: a
gadgetfs: configuration #4
sierra 1-1:4.1: Sierra USB modem converter detected
usb 1-1: Sierra USB modem converter now attached to ttyUSB0
sierra 1-1:4.153: Sierra USB modem converter detected
gadgetfs: disconnected
usb 1-1: USB disconnect, device number 2
sierra ttyUSB0: Sierra USB modem converter now disconnected from ttyUSB0
sierra 1-1:4.1: device disconnected
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x4504/0x4550
Read of size 8 at addr ffff8800674df790 by task kworker/1:2/1846

CPU: 1 PID: 1846 Comm: kworker/1:2 Not tainted
4.14.0-rc2-42660-g24b7bd59eec0 #277
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
__dump_stack lib/dump_stack.c:16
dump_stack+0x292/0x395 lib/dump_stack.c:52
print_address_description+0x78/0x280 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351
kasan_report+0x23d/0x350 mm/kasan/report.c:409
__asan_report_load8_noabort+0x19/0x20 mm/kasan/report.c:430
__lock_acquire+0x4504/0x4550 kernel/locking/lockdep.c:3376
lock_acquire+0x259/0x620 kernel/locking/lockdep.c:4002
__mutex_lock_common kernel/locking/mutex.c:756
__mutex_lock+0x18e/0x1a50 kernel/locking/mutex.c:893
mutex_lock_nested+0x1b/0x20 kernel/locking/mutex.c:908
usb_serial_disconnect+0x69/0x2e0 drivers/usb/serial/usb-serial.c:1084
usb_unbind_interface+0x21c/0xa90 drivers/usb/core/driver.c:423
__device_release_driver drivers/base/dd.c:861
device_release_driver_internal+0x4f4/0x5c0 drivers/base/dd.c:893
device_release_driver+0x1e/0x30 drivers/base/dd.c:918
bus_remove_device+0x2f4/0x4b0 drivers/base/bus.c:565
device_del+0x5c4/0xab0 drivers/base/core.c:1985
usb_disable_device+0x1e9/0x680 drivers/usb/core/message.c:1170
usb_disconnect+0x260/0x7a0 drivers/usb/core/hub.c:2124
hub_port_connect drivers/usb/core/hub.c:4754
hub_port_connect_change drivers/usb/core/hub.c:5009
port_event drivers/usb/core/hub.c:5115
hub_event+0x1318/0x3740 drivers/usb/core/hub.c:5195
process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
worker_thread+0x221/0x1850 kernel/workqueue.c:2253
kthread+0x3a1/0x470 kernel/kthread.c:231
ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

Allocated by task 1846:
save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459
kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
kmem_cache_alloc_trace+0x11e/0x2d0 mm/slub.c:2772
kmalloc ./include/linux/slab.h:493
kzalloc ./include/linux/slab.h:666
create_serial drivers/usb/serial/usb-serial.c:605
usb_serial_probe+0x36f/0x4090 drivers/usb/serial/usb-serial.c:892
usb_probe_interface+0x35d/0x8e0 drivers/usb/core/driver.c:361
really_probe drivers/base/dd.c:413
driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
__device_attach_driver+0x230/0x290 drivers/base/dd.c:653
bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
__device_attach+0x26e/0x3d0 drivers/base/dd.c:710
device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
device_add+0xd0b/0x1660 drivers/base/core.c:1835
usb_set_configuration+0x104e/0x1870 drivers/usb/core/message.c:1932
generic_probe+0x73/0xe0 drivers/usb/core/generic.c:174
usb_probe_device+0xaf/0xe0 drivers/usb/core/driver.c:266
really_probe drivers/base/dd.c:413
driver_probe_device+0x610/0xa00 drivers/base/dd.c:557
__device_attach_driver+0x230/0x290 drivers/base/dd.c:653
bus_for_each_drv+0x161/0x210 drivers/base/bus.c:463
__device_attach+0x26e/0x3d0 drivers/base/dd.c:710
device_initial_probe+0x1f/0x30 drivers/base/dd.c:757
bus_probe_device+0x1eb/0x290 drivers/base/bus.c:523
device_add+0xd0b/0x1660 drivers/base/core.c:1835
usb_new_device+0x7b8/0x1020 drivers/usb/core/hub.c:2457
hub_port_connect drivers/usb/core/hub.c:4903
hub_port_connect_change drivers/usb/core/hub.c:5009
port_event drivers/usb/core/hub.c:5115
hub_event+0x194d/0x3740 drivers/usb/core/hub.c:5195
process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
worker_thread+0x221/0x1850 kernel/workqueue.c:2253
kthread+0x3a1/0x470 kernel/kthread.c:231
ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

Freed by task 1846:
save_stack_trace+0x1b/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459
kasan_slab_free+0x72/0xc0 mm/kasan/kasan.c:524
slab_free_hook mm/slub.c:1390
slab_free_freelist_hook mm/slub.c:1412
slab_free mm/slub.c:2988
kfree+0xf6/0x2f0 mm/slub.c:3919
destroy_serial drivers/usb/serial/usb-serial.c:153
kref_put ./include/linux/kref.h:70
usb_serial_put+0x218/0x430 drivers/usb/serial/usb-serial.c:158
usb_serial_console_disconnect+0xb2/0xd0 drivers/usb/serial/console.c:270
usb_serial_disconnect+0x5f/0x2e0 drivers/usb/serial/usb-serial.c:1082
usb_unbind_interface+0x21c/0xa90 drivers/usb/core/driver.c:423
__device_release_driver drivers/base/dd.c:861
device_release_driver_internal+0x4f4/0x5c0 drivers/base/dd.c:893
device_release_driver+0x1e/0x30 drivers/base/dd.c:918
bus_remove_device+0x2f4/0x4b0 drivers/base/bus.c:565
device_del+0x5c4/0xab0 drivers/base/core.c:1985
usb_disable_device+0x1e9/0x680 drivers/usb/core/message.c:1170
usb_disconnect+0x260/0x7a0 drivers/usb/core/hub.c:2124
hub_port_connect drivers/usb/core/hub.c:4754
hub_port_connect_change drivers/usb/core/hub.c:5009
port_event drivers/usb/core/hub.c:5115
hub_event+0x1318/0x3740 drivers/usb/core/hub.c:5195
process_one_work+0xc7f/0x1db0 kernel/workqueue.c:2119
worker_thread+0x221/0x1850 kernel/workqueue.c:2253
kthread+0x3a1/0x470 kernel/kthread.c:231
ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:431

The buggy address belongs to the object at ffff8800674df680
which belongs to the cache kmalloc-512 of size 512
The buggy address is located 272 bytes inside of
512-byte region [ffff8800674df680, ffff8800674df880)
The buggy address belongs to the page:
page:ffffea00019d3780 count:1 mapcount:0 mapping: (null)
index:0xffff8800674def00 compound_mapcount: 0
flags: 0x100000000008100(slab|head)
raw: 0100000000008100 0000000000000000 ffff8800674def00 00000001800c0008
raw: 0000000000000000 0000000100000001 ffff88006c403080 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
ffff8800674df680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8800674df700: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8800674df780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
^
ffff8800674df800: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
ffff8800674df880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================

[Johan Hovold]

Thanks for reporting this. I was able to reproduce the bug from the
information you provided here, and incidentally discovered a
long-standing related issue which I've now also fixed.

Thanks,
Johan