* Re: [PATCH] HID: i2c-hid: prevent buffer overflow in early IRQ
[not found] <1418342565-22161-1-git-send-email-gwendal@chromium.org>
@ 2014-12-12 1:17 ` Benjamin Tissoires
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From: Benjamin Tissoires @ 2014-12-12 1:17 UTC (permalink / raw)
To: Gwendal Grignou; +Cc: jkosina, stable, linux-input
On Dec 11 2014 or thereabouts, Gwendal Grignou wrote:
> 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>
> Cc: stable@vger.kernel.org
> ---
Yep, well spotted. Makes sense to me.
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Cheers,
Benjamin
> drivers/hid/i2c-hid/i2c-hid.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/hid/i2c-hid/i2c-hid.c b/drivers/hid/i2c-hid/i2c-hid.c
> index 226375e..d32037c 100644
> --- a/drivers/hid/i2c-hid/i2c-hid.c
> +++ b/drivers/hid/i2c-hid/i2c-hid.c
> @@ -370,7 +370,7 @@ 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) {
> --
> 2.2.0.rc0.207.ga3a616c
>
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