syzbot


KASAN: use-after-free Read in mcba_usb_disconnect

Status: fixed on 2019/11/29 15:48
Subsystems: can usb
[Documentation on labels]
Reported-by: syzbot+e29b17e5042bbc56fae9@syzkaller.appspotmail.com
Fix commit: 4d6636498c41 can: mcba_usb: fix use-after-free on disconnect
First crash: 1697d, last: 1664d
Duplicate bugs (1)
duplicates (1):
Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
KASAN: use-after-free Read in usb_kill_anchored_urbs usb can C 6 1705d 1808d 0/26 closed as dup on 2020/06/18 12:01
Discussions (8)
Title Replies (including bot) Last reply
[PATCH 4.19 000/125] 4.19.84-stable review 144 (144) 2019/11/18 14:33
[PATCH 4.14 000/105] 4.14.154-stable review 115 (115) 2019/11/13 09:55
[PATCH 5.3 000/193] 5.3.11-stable review 200 (200) 2019/11/12 18:26
[PATCH 03/33] can: mcba_usb: fix use-after-free on disconnect 1 (1) 2019/11/05 16:31
[PATCH 03/29] can: mcba_usb: fix use-after-free on disconnect 1 (1) 2019/10/10 12:17
[PATCH 0/2] can: fix use-after-free on USB disconnect 4 (4) 2019/10/04 20:45
Reminder: 67 active syzbot reports in usb subsystem 1 (1) 2019/10/04 03:38
KASAN: use-after-free Read in mcba_usb_disconnect 1 (2) 2019/10/01 10:32

Sample crash report:
mcba_usb 1-1:0.180 can1: Failed to send cmd (169)
mcba_usb 1-1:0.180: Microchip CAN BUS Analyzer connected
usb 1-1: USB disconnect, device number 2
mcba_usb 1-1:0.95 can0: device disconnected
==================================================================
BUG: KASAN: use-after-free in __lock_acquire+0x3377/0x3eb0 kernel/locking/lockdep.c:3828
Read of size 8 at addr ffff8881d2e98f48 by task kworker/0:1/12

CPU: 0 PID: 12 Comm: kworker/0:1 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
 __lock_acquire+0x3377/0x3eb0 kernel/locking/lockdep.c:3828
 lock_acquire+0x127/0x320 kernel/locking/lockdep.c:4487
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:128 [inline]
 _raw_spin_lock_irq+0x2d/0x40 kernel/locking/spinlock.c:167
 spin_lock_irq include/linux/spinlock.h:363 [inline]
 usb_kill_anchored_urbs+0x1e/0x110 drivers/usb/core/urb.c:787
 mcba_urb_unlink drivers/net/can/usb/mcba_usb.c:711 [inline]
 mcba_usb_disconnect+0xd6/0xe4 drivers/net/can/usb/mcba_usb.c:881
 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
 __device_release_driver drivers/base/dd.c:1134 [inline]
 device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1165
 bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:532
 device_del+0x420/0xb10 drivers/base/core.c:2375
 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
 process_scheduled_works kernel/workqueue.c:2331 [inline]
 worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417
 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 page:
page:ffffea00074ba600 refcount:0 mapcount:-128 mapping:0000000000000000 index:0x0
flags: 0x200000000000000()
raw: 0200000000000000 ffffea0007479208 ffff88821fffac18 0000000000000000
raw: 0000000000000000 0000000000000003 00000000ffffff7f 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881d2e98e00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d2e98e80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff8881d2e98f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                                              ^
 ffff8881d2e98f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881d2e99000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/09/30 03:46 https://github.com/google/kasan.git usb-fuzzer 2994c07743fe c1ad5441 .config console log report syz C ci2-upstream-usb
2019/11/02 13:43 https://github.com/google/kasan.git usb-fuzzer ff6409a6ec35 997ccc67 .config console log report ci2-upstream-usb
* Struck through repros no longer work on HEAD.