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authorAlan Stern <stern@rowland.harvard.edu>2019-10-03 14:53:59 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-11-06 12:43:33 +0100
commite13a3d84494ca7b560551a9927231e7ecf27d96a (patch)
tree083e377ae8ba3a35c8e719577fa6b64661d1a2c5 /drivers/hid/hid-logitech-hidpp.c
parent8390ff01a88d2f0dab63e8c50ba7e666f52a38ab (diff)
HID: Fix assumption that devices have inputs
commit d9d4b1e46d9543a82c23f6df03f4ad697dab361b upstream. The syzbot fuzzer found a slab-out-of-bounds write bug in the hid-gaff driver. The problem is caused by the driver's assumption that the device must have an input report. While this will be true for all normal HID input devices, a suitably malicious device can violate the assumption. The same assumption is present in over a dozen other HID drivers. This patch fixes them by checking that the list of hid_inputs for the hid_device is nonempty before allowing it to be used. Reported-and-tested-by: syzbot+403741a091bf41d4ae79@syzkaller.appspotmail.com Signed-off-by: Alan Stern <stern@rowland.harvard.edu> CC: <stable@vger.kernel.org> Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/hid/hid-logitech-hidpp.c')
-rw-r--r--drivers/hid/hid-logitech-hidpp.c11
1 files changed, 9 insertions, 2 deletions
diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index b705cbb58ca6..4706fb852eaf 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -1867,8 +1867,8 @@ static void hidpp_ff_destroy(struct ff_device *ff)
static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
{
struct hid_device *hid = hidpp->hid_dev;
- struct hid_input *hidinput = list_entry(hid->inputs.next, struct hid_input, list);
- struct input_dev *dev = hidinput->input;
+ struct hid_input *hidinput;
+ struct input_dev *dev;
const struct usb_device_descriptor *udesc = &(hid_to_usb_dev(hid)->descriptor);
const u16 bcdDevice = le16_to_cpu(udesc->bcdDevice);
struct ff_device *ff;
@@ -1877,6 +1877,13 @@ static int hidpp_ff_init(struct hidpp_device *hidpp, u8 feature_index)
int error, j, num_slots;
u8 version;
+ 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 (!dev) {
hid_err(hid, "Struct input_dev not set!\n");
return -EINVAL;