On Thu, 19 Sep 2019, Andrey Konovalov wrote: > On Tue, Sep 17, 2019 at 8:24 PM Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > > > > 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+403741a091bf41d4ae79@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > 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 syzkaller@xxxxxxxxxxxxxxxx. > > > > > > 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. > > BTW, these two reports look fairly similar: > > https://syzkaller.appspot.com/bug?extid=94e2b9e9c7d1dd332345 > https://syzkaller.appspot.com/bug?extid=1e86e2ccce227cca899b Indeed they do. I don't have time to patch them now; maybe next week. Unless you or someone else would like to do it first... :-) Essentially the same fix should work for each of these -- looks like they were written using copy-and-paste. In fact, a quick grep through drivers/hid/*.c shows about 9 of them with the same suspect initialization code for hidinput. Alan Stern > > 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;
