ALSA: usb-audio: scarlett2: Use struct_size() helper in scarlett2_usb()

Make use of the struct_size() helper instead of an open-coded version,
in order to avoid any potential type mistakes or integer overflows that,
in the worst scenario, could lead to heap overflows.

Also, address the following sparse warnings:
sound/usb/mixer_scarlett_gen2.c:1064:28: warning: using sizeof on a flexible structure
sound/usb/mixer_scarlett_gen2.c:1065:29: warning: using sizeof on a flexible structure

Link: https://github.com/KSPP/linux/issues/174
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20220120211600.GA28841@embeddedor
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Gustavo A. R. Silva 2022-01-20 15:16:00 -06:00 committed by Takashi Iwai
parent e783362eb5
commit 2b101256fd

View file

@ -1061,9 +1061,9 @@ static int scarlett2_usb(
{
struct scarlett2_data *private = mixer->private_data;
struct usb_device *dev = mixer->chip->dev;
u16 req_buf_size = sizeof(struct scarlett2_usb_packet) + req_size;
u16 resp_buf_size = sizeof(struct scarlett2_usb_packet) + resp_size;
struct scarlett2_usb_packet *req, *resp = NULL;
size_t req_buf_size = struct_size(req, data, req_size);
size_t resp_buf_size = struct_size(resp, data, resp_size);
int err;
req = kmalloc(req_buf_size, GFP_KERNEL);
@ -1111,7 +1111,7 @@ static int scarlett2_usb(
usb_audio_err(
mixer->chip,
"Scarlett Gen 2/3 USB response result cmd %x was %d "
"expected %d\n",
"expected %zu\n",
cmd, err, resp_buf_size);
err = -EINVAL;
goto unlock;