HID: i2c-hid: prevent buffer overflow in early IRQ

Before ->start() is called, bufsize size is set to HID_MIN_BUFFER_SIZE,
64 bytes. While processing the IRQ, we were asking to receive up to
wMaxInputLength bytes, which can be bigger than 64 bytes.

Later, when ->start is run, a proper bufsize will be calculated.

Given wMaxInputLength is said to be unreliable in other part of the
code, set to receive only what we can even if it results in truncated
reports.

Signed-off-by: Gwendal Grignou <gwendal@chromium.org>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This commit is contained in:
Gwendal Grignou 2014-12-11 16:02:45 -08:00 committed by Jiri Kosina
parent dff6741688
commit d1c7e29e8d

View File

@ -369,7 +369,7 @@ static int i2c_hid_hwreset(struct i2c_client *client)
static void i2c_hid_get_input(struct i2c_hid *ihid)
{
int ret, ret_size;
int size = le16_to_cpu(ihid->hdesc.wMaxInputLength);
int size = ihid->bufsize;
ret = i2c_master_recv(ihid->client, ihid->inbuf, size);
if (ret != size) {