Am Donnerstag, den 25.07.2019, 05:08 -0700 schrieb syzbot: > Hello, > > syzbot found the following crash on: > > HEAD commit: 6a3599ce 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=14e6d3d0600000 > kernel config: https://syzkaller.appspot.com/x/.config?x=700ca426ab83faae > dashboard link: https://syzkaller.appspot.com/bug?extid=965152643a75a56737be > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1663f8cc600000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=145f2978600000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+965152643a75a56737be@xxxxxxxxxxxxxxxxxxxxxxxxx #syz test: https://github.com/google/kasan.git usb-fuzzer-usb-testing-2019.07.11 >From 93eb5c925a204804b82a7526a8b9252a102fd339 Mon Sep 17 00:00:00 2001 From: Oliver Neukum <oneukum@xxxxxxxx> Date: Thu, 25 Jul 2019 14:37:53 +0200 Subject: [PATCH] holtek: test for sanity of intfdata The ioctl handler uses the intfdata of a second interface, which may not be present in a broken or malicious device, hence the intfdata needs to be checked for NULL. Reported-by: syzbot+965152643a75a56737be@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Oliver Neukum <oneukum@xxxxxxxx> --- drivers/hid/hid-holtek-kbd.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/hid/hid-holtek-kbd.c b/drivers/hid/hid-holtek-kbd.c index b3d502421b79..67ce75dfa9a4 100644 --- a/drivers/hid/hid-holtek-kbd.c +++ b/drivers/hid/hid-holtek-kbd.c @@ -123,9 +123,14 @@ static int holtek_kbd_input_event(struct input_dev *dev, unsigned int type, /* Locate the boot interface, to receive the LED change events */ struct usb_interface *boot_interface = usb_ifnum_to_if(usb_dev, 0); - - struct hid_device *boot_hid = usb_get_intfdata(boot_interface); - struct hid_input *boot_hid_input = list_first_entry(&boot_hid->inputs, + struct hid_device *boot_hid; + struct hid_input *boot_hid_input; + + if (unlikely(boot_interface == NULL)) + return -ENODEV; + + boot_hid = usb_get_intfdata(boot_interface); + boot_hid_input = list_first_entry(&boot_hid->inputs, struct hid_input, list); return boot_hid_input->input->event(boot_hid_input->input, type, code, -- 2.16.4
