On Mon, Aug 19, 2019 at 4:48 PM syzbot <syzbot+68a449e448766880a109@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: d0847550 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=15fb03ba600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=dbc9c80cc095da19 > dashboard link: https://syzkaller.appspot.com/bug?extid=68a449e448766880a109 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > Unfortunately, I don't have any reproducer for this crash yet. > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+68a449e448766880a109@xxxxxxxxxxxxxxxxxxxxxxxxx > > usb 1-1: USB disconnect, device number 99 > ================================================================== > BUG: KASAN: double-free or invalid-free in iowarrior_delete > drivers/usb/misc/iowarrior.c:243 [inline] > BUG: KASAN: double-free or invalid-free in iowarrior_disconnect+0x1f8/0x2c0 > drivers/usb/misc/iowarrior.c:894 > > CPU: 1 PID: 3267 Comm: kworker/1:6 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_invalid_free+0x61/0xa0 mm/kasan/report.c:444 > __kasan_slab_free+0x162/0x180 mm/kasan/common.c:428 > 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 > iowarrior_delete drivers/usb/misc/iowarrior.c:243 [inline] > iowarrior_disconnect+0x1f8/0x2c0 drivers/usb/misc/iowarrior.c:894 > 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: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 2745: > 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:557 [inline] > iowarrior_probe+0x526/0x10b2 drivers/usb/misc/iowarrior.c:800 > usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361 > 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_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+0x281/0x6d0 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 4897: > 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 > iowarrior_delete drivers/usb/misc/iowarrior.c:243 [inline] > iowarrior_release+0x123/0x280 drivers/usb/misc/iowarrior.c:670 > __fput+0x2d7/0x840 fs/file_table.c:280 > task_work_run+0x13f/0x1c0 kernel/task_work.c:113 > tracehook_notify_resume include/linux/tracehook.h:188 [inline] > exit_to_usermode_loop+0x1d2/0x200 arch/x86/entry/common.c:163 > prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline] > syscall_return_slowpath arch/x86/entry/common.c:274 [inline] > do_syscall_64+0x45f/0x580 arch/x86/entry/common.c:299 > entry_SYSCALL_64_after_hwframe+0x49/0xbe > > The buggy address belongs to the object at ffff8881da290558 > which belongs to the cache kmalloc-8 of size 8 > The buggy address is located 0 bytes inside of > 8-byte region [ffff8881da290558, ffff8881da290560) > The buggy address belongs to the page: > page:ffffea000768a400 refcount:1 mapcount:0 mapping:ffff8881da003900 > index:0xffff8881da290de0 > flags: 0x200000000000200(slab) > raw: 0200000000000200 ffffea0007343c00 0000000600000006 ffff8881da003900 > raw: ffff8881da290de0 0000000080aa002f 00000001ffffffff 0000000000000000 > page dumped because: kasan: bad access detected > > Memory state around the buggy address: > ffff8881da290400: fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc > ffff8881da290480: fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb > > ffff8881da290500: fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc > ^ > ffff8881da290580: fc fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc > ffff8881da290600: fb fc fc fb fc fc fb fc fc fb fc fc fb fc fc fb > ================================================================== > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. #syz dup: KASAN: use-after-free Read in iowarrior_disconnect https://syzkaller.appspot.com/bug?id=c59a8f0485cd6634443cdf23cdbf3ea264dd888d