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
