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KASAN: use-after-free Read in device_release_driver_internal

Status: fixed on 2019/09/06 20:45
Subsystems: usb
[Documentation on labels]
Reported-by: syzbot+1b2449b7b5dc240d107a@syzkaller.appspotmail.com
Fix commit: c52873e5a1ef usb: cdc-acm: make sure a refcount is taken early enough
First crash: 1968d, last: 1944d
▶ ▼ Discussions (9)
Title Replies (including bot) Last reply
[PATCH 3.16 00/83] 3.16.78-rc1 review 88 (88) 2019/11/21 21:42
[PATCH 5.2 000/135] 5.2.10-stable review 160 (160) 2019/08/27 10:51
[PATCH 4.4 00/78] 4.4.190-stable review 91 (91) 2019/08/24 18:14
[PATCH 4.9 000/103] 4.9.190-stable review 109 (109) 2019/08/24 17:59
[PATCH 4.14 00/71] 4.14.140-stable review 79 (79) 2019/08/24 17:55
[PATCH 4.19 00/85] 4.19.68-stable review 91 (91) 2019/08/24 17:51
KASAN: use-after-free Read in device_release_driver_internal 24 (29) 2019/08/13 15:16
[PATCH] usb: cdc-acm: make sure a refcount is taken early enough 1 (1) 2019/08/08 14:21
Reminder: 67 open syzbot bugs in usb subsystem 1 (1) 2019/07/24 01:35
▶ ▼ Last patch testing requests (4)
Created Duration User Patch Repo Result
2019/08/07 18:05 16m stern@rowland.harvard.edu patch https://github.com/google/kasan.git 6a3599ce OK
2019/08/07 17:40 10m stern@rowland.harvard.edu patch https://github.com/google/kasan.git 6a3599ce report log
2019/08/07 13:45 17m andreyknvl@google.com patch https://github.com/google/kasan.git 6a3599ce OK
2019/08/07 13:44 10m andreyknvl@google.com https://github.com/google/kasan.git 6a3599ce report log

Sample crash report:
usb 1-1: bad CDC descriptors
cdc_acm 1-1:0.236: invalid descriptor buffer length
cdc_acm 1-1:0.236: No union descriptor, testing for castrated device
cdc_acm: probe of 1-1:0.236 failed with error -12
usb 1-1: USB disconnect, device number 2
==================================================================
BUG: KASAN: use-after-free in __mutex_lock_common kernel/locking/mutex.c:912 [inline]
BUG: KASAN: use-after-free in __mutex_lock+0xf23/0x1360 kernel/locking/mutex.c:1077
Read of size 8 at addr ffff8881d295bd08 by task kworker/1:2/83

CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.3.0-rc4+ #26
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+0x6a/0x32c mm/kasan/report.c:351
 __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482
 kasan_report+0xe/0x12 mm/kasan/common.c:612
 __mutex_lock_common kernel/locking/mutex.c:912 [inline]
 __mutex_lock+0xf23/0x1360 kernel/locking/mutex.c:1077
 device_release_driver_internal+0x23/0x500 drivers/base/dd.c:1162
 bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
 device_del+0x420/0xb10 drivers/base/core.c:2339
 usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
 usb_disconnect+0x284/0x8d0 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+0x1454/0x3640 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 83:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc mm/kasan/common.c:487 [inline]
 __kasan_kmalloc.constprop.0+0xbf/0xd0 mm/kasan/common.c:460
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:748 [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+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x101/0x1b0 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:454
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:514
 device_add+0xae6/0x16f0 drivers/base/core.c:2165
 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 83:
 save_stack+0x1b/0x80 mm/kasan/common.c:69
 set_track mm/kasan/common.c:77 [inline]
 __kasan_slab_free+0x130/0x180 mm/kasan/common.c:449
 slab_free_hook mm/slub.c:1423 [inline]
 slab_free_freelist_hook mm/slub.c:1474 [inline]
 slab_free mm/slub.c:3016 [inline]
 kfree+0xe4/0x2f0 mm/slub.c:3957
 device_release+0x71/0x200 drivers/base/core.c:1064
 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+0x1b/0x30 drivers/base/core.c:2264
 klist_put+0xce/0x170 lib/klist.c:221
 bus_remove_device+0x3a4/0x4a0 drivers/base/bus.c:552
 device_del+0x420/0xb10 drivers/base/core.c:2339
 usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
 usb_disconnect+0x284/0x8d0 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+0x1454/0x3640 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 ffff8881d295bb80
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 392 bytes inside of
 2048-byte region [ffff8881d295bb80, ffff8881d295c380)
The buggy address belongs to the page:
page:ffffea00074a5600 refcount:1 mapcount:0 mapping:ffff8881da00c000 index:0x0 compound_mapcount: 0
flags: 0x200000000010200(slab|head)
raw: 0200000000010200 dead000000000100 dead000000000122 ffff8881da00c000
raw: 0000000000000000 00000000800f000f 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d295bc00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d295bc80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff8881d295bd00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                      ^
 ffff8881d295bd80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881d295be00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/08/16 05:19 https://github.com/google/kasan.git usb-fuzzer d0847550e22d 8fd428a1 .config console log report syz C ci2-upstream-usb
2019/08/14 10:39 https://github.com/google/kasan.git usb-fuzzer d0847550e22d ef801a3e .config console log report syz C ci2-upstream-usb
2019/08/04 00:08 https://github.com/google/kasan.git usb-fuzzer e96407b49762 6affd8e8 .config console log report syz C ci2-upstream-usb
2019/07/29 22:44 https://github.com/google/kasan.git usb-fuzzer 7f7867ff95bf f67095ee .config console log report syz C ci2-upstream-usb
2019/07/23 12:14 https://github.com/google/kasan.git usb-fuzzer 6a3599ceaa39 bb071d58 .config console log report syz C ci2-upstream-usb
* Struck through repros no longer work on HEAD.