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

[Andrey Konovalov]

On Tue, Oct 1, 2019 at 12:31 PM Johan Hovold <johan@xxxxxxxxxx> wrote:
>
> On Tue, Jun 11, 2019 at 10:25:05AM -0700, syzbot 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=15df4ecaa00000
> > kernel config:  https://syzkaller.appspot.com/x/.config?x=193d8457178b3229
> > dashboard link: https://syzkaller.appspot.com/bug?extid=eb6ab607626fd1dac0f1
> > compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=11847e7aa00000
> > C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=14ef5f2ea00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: syzbot+eb6ab607626fd1dac0f1@xxxxxxxxxxxxxxxxxxxxxxxxx
> >
> > mcba_usb 1-1:0.116 can0: Failed to send cmd (169)
> > mcba_usb 1-1:0.116 can0: failed tx_urb -2
> > mcba_usb 1-1:0.116 can0: Failed to send cmd (169)
> > mcba_usb 1-1:0.116: Microchip CAN BUS Analyzer connected
> > usb 1-1: USB disconnect, device number 2
> > mcba_usb 1-1:0.116 can0: device disconnected
> > ==================================================================
> > BUG: KASAN: use-after-free in __lock_acquire+0x3a5d/0x5340
> > kernel/locking/lockdep.c:3664
> > Read of size 8 at addr ffff8881d44c63c8 by task kworker/0:1/12
> >
> > CPU: 0 PID: 12 Comm: kworker/0:1 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
> >   __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:722 [inline]
> >   mcba_usb_disconnect+0xd6/0xe4 drivers/net/can/usb/mcba_usb.c:892
> >   usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
> >   __device_release_driver drivers/base/dd.c:1081 [inline]
> >   device_release_driver_internal+0x404/0x4c0 drivers/base/dd.c:1112
> >   bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
> >   device_del+0x460/0xb80 drivers/base/core.c:2274
> >   usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
> >   usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2197
> >   hub_port_connect drivers/usb/core/hub.c:4940 [inline]
> >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> >   port_event drivers/usb/core/hub.c:5350 [inline]
> >   hub_event+0x1409/0x3590 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 12:
> >   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_node include/linux/slab.h:590 [inline]
> >   kvmalloc_node+0x61/0xf0 mm/util.c:430
> >   kvmalloc include/linux/mm.h:637 [inline]
> >   kvzalloc include/linux/mm.h:645 [inline]
> >   alloc_netdev_mqs+0x97/0xce0 net/core/dev.c:9154
> >   alloc_candev_mqs+0x58/0x320 drivers/net/can/dev.c:738
> >   mcba_usb_probe+0xaf/0xbca drivers/net/can/usb/mcba_usb.c:810
> >   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
> >
> > Freed by task 12:
> >   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
> >   kvfree+0x59/0x60 mm/util.c:459
> >   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+0x1b/0x30 drivers/base/core.c:2210
> >   free_netdev+0x317/0x420 net/core/dev.c:9265
> >   mcba_usb_disconnect+0xca/0xe4 drivers/net/can/usb/mcba_usb.c:890
> >   usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:423
> >   __device_release_driver drivers/base/dd.c:1081 [inline]
> >   device_release_driver_internal+0x404/0x4c0 drivers/base/dd.c:1112
> >   bus_remove_device+0x2dc/0x4a0 drivers/base/bus.c:556
> >   device_del+0x460/0xb80 drivers/base/core.c:2274
> >   usb_disable_device+0x211/0x690 drivers/usb/core/message.c:1237
> >   usb_disconnect+0x284/0x830 drivers/usb/core/hub.c:2197
> >   hub_port_connect drivers/usb/core/hub.c:4940 [inline]
> >   hub_port_connect_change drivers/usb/core/hub.c:5204 [inline]
> >   port_event drivers/usb/core/hub.c:5350 [inline]
> >   hub_event+0x1409/0x3590 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
> >
> > The buggy address belongs to the object at ffff8881d44c5500
> >   which belongs to the cache kmalloc-4k of size 4096
> > The buggy address is located 3784 bytes inside of
> >   4096-byte region [ffff8881d44c5500, ffff8881d44c6500)
> > The buggy address belongs to the page:
> > page:ffffea0007513000 refcount:1 mapcount:0 mapping:ffff8881dac02600
> > index:0x0 compound_mapcount: 0
> > flags: 0x200000000010200(slab|head)
> > raw: 0200000000010200 dead000000000100 dead000000000200 ffff8881dac02600
> > raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
> > page dumped because: kasan: bad access detected
> >
> > Memory state around the buggy address:
> >   ffff8881d44c6280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >   ffff8881d44c6300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > > ffff8881d44c6380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >                                                ^
> >   ffff8881d44c6400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> >   ffff8881d44c6480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> > ==================================================================
>
> #sys dup: KASAN: use-after-free Read in mcba_usb_disconnect

#syz dup: KASAN: use-after-free Read in mcba_usb_disconnect