On Sat, Mar 16, 2024 at 11:33:53PM +0300, Grigory Bazilevich wrote:
> Passing a size argument greater than or equal to MAX_BUF_LEN causes
> a buffer overflow when the checksum is written.
>
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
>
> Fixes: fe6d8a9c8e64 ("usb: typec: anx7411: Add Analogix PD ANX7411 support")
> Signed-off-by: Grigory Bazilevich <bazilevich@xxxxxxxxx>
Reviewed-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
> ---
> drivers/usb/typec/anx7411.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/usb/typec/anx7411.c b/drivers/usb/typec/anx7411.c
> index b12a07edc71b..70ba56dfb22b 100644
> --- a/drivers/usb/typec/anx7411.c
> +++ b/drivers/usb/typec/anx7411.c
> @@ -733,7 +733,7 @@ static int anx7411_send_msg(struct anx7411_data *ctx, u8 type, u8 *buf, u8 size)
> u8 crc;
> int ret;
>
> - size = min_t(u8, size, (u8)MAX_BUF_LEN);
> + size = min_t(u8, size, (u8)(MAX_BUF_LEN - 1));
> memcpy(msg->buf, buf, size);
> msg->msg_type = type;
> /* msg len equals buffer length + msg_type */
> --
> 2.39.2
--
heikki
