On Mon, Sep 30, 2019 at 03:39:15PM -0700, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: 2994c077 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=173b5acd600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=69ddefac6929256a > dashboard link: https://syzkaller.appspot.com/bug?extid=e29b17e5042bbc56fae9 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10ec8e19600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=107ad813600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+e29b17e5042bbc56fae9@xxxxxxxxxxxxxxxxxxxxxxxxx > > 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 > ================================================================== Fix posted https://lkml.kernel.org/r/20191001102914.4567-2-johan@xxxxxxxxxx Johan
