On Mon, 16 Sep 2019, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: f0df5c1b 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=14045831600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=5c6633fa4ed00be5 > dashboard link: https://syzkaller.appspot.com/bug?extid=403741a091bf41d4ae79 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=13c1e62d600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=166a3a95600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+403741a091bf41d4a...@syzkaller.appspotmail.com > > usb 1-1: config 0 interface 0 altsetting 0 has 1 endpoint descriptor, > different from the interface descriptor's value: 9 > usb 1-1: New USB device found, idVendor=0e8f, idProduct=0012, bcdDevice= > 0.00 > usb 1-1: New USB device strings: Mfr=0, Product=0, SerialNumber=0 > usb 1-1: config 0 descriptor?? > greenasia 0003:0E8F:0012.0001: unknown main item tag 0x0 > greenasia 0003:0E8F:0012.0001: hidraw0: USB HID v0.00 Device [HID > 0e8f:0012] on usb-dummy_hcd.0-1/input0 > ================================================================== > BUG: KASAN: slab-out-of-bounds in set_bit > include/asm-generic/bitops-instrumented.h:28 [inline] > BUG: KASAN: slab-out-of-bounds in gaff_init drivers/hid/hid-gaff.c:97 > [inline] > BUG: KASAN: slab-out-of-bounds in ga_probe+0x1fd/0x6f0 > drivers/hid/hid-gaff.c:146 > Write of size 8 at addr ffff8881d9acafc0 by task kworker/1:1/78 > > CPU: 1 PID: 78 Comm: kworker/1:1 Not tainted 5.3.0-rc7+ #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+0x6a/0x32c mm/kasan/report.c:351 > __kasan_report.cold+0x1a/0x33 mm/kasan/report.c:482 > kasan_report+0xe/0x12 mm/kasan/common.c:618 > check_memory_region_inline mm/kasan/generic.c:185 [inline] > check_memory_region+0x128/0x190 mm/kasan/generic.c:192 > set_bit include/asm-generic/bitops-instrumented.h:28 [inline] > gaff_init drivers/hid/hid-gaff.c:97 [inline] > ga_probe+0x1fd/0x6f0 drivers/hid/hid-gaff.c:146 > hid_device_probe+0x2be/0x3f0 drivers/hid/hid-core.c:2209 > really_probe+0x281/0x6d0 drivers/base/dd.c:548 > driver_probe_device+0x101/0x1b0 drivers/base/dd.c:721 > __device_attach_driver+0x > > > --- > 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 syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches
The driver assumes that the device contains an input. Alan Stern https://github.com/google/kasan.git f0df5c1b drivers/hid/hid-gaff.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) Index: usb-devel/drivers/hid/hid-gaff.c =================================================================== --- usb-devel.orig/drivers/hid/hid-gaff.c +++ usb-devel/drivers/hid/hid-gaff.c @@ -64,14 +64,20 @@ static int gaff_init(struct hid_device * { struct gaff_device *gaff; struct hid_report *report; - struct hid_input *hidinput = list_entry(hid->inputs.next, - struct hid_input, list); + struct hid_input *hidinput; struct list_head *report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list; struct list_head *report_ptr = report_list; - struct input_dev *dev = hidinput->input; + struct input_dev *dev; int error; + if (list_empty(&hid->inputs)) { + hid_err(hid, "no inputs found\n"); + return -ENODEV; + } + hidinput = list_entry(hid->inputs.next, struct hid_input, list); + dev = hidinput->input; + if (list_empty(report_list)) { hid_err(hid, "no output reports found\n"); return -ENODEV;
