On 7/14/2023 5:41 AM, Pranjal Ramajor Asha Kanojiya wrote:
On 7/11/2023 1:50 PM, Dan Carpenter wrote:There are several issues in this code. The check at the start of the loop: if (user_len >= user_msg->len) { This check does not ensure that we have enough space for the trans_hdr (8 bytes). Instead the check needs to be: if (user_len > user_msg->len - sizeof(*trans_hdr)) { That subtraction is done as an unsigned long we want to avoid negatives. Add a lower bound to the start of the function. if (user_msg->len < sizeof(*trans_hdr)) There is a second integer underflow which can happen if trans_hdr->len is zero inside the encode_passthrough() function.memcpy(out_trans->data, in_trans->data, in_trans->hdr.len - sizeof(in_trans->hdr));Instead of adding a check to encode_passthrough() it's better to check in this central place. Add that check: if (trans_hdr->len < sizeof(trans_hdr) The final concern is that the "user_len + trans_hdr->len" might have an integer overflow bug. Use size_add() to prevent that. - if (user_len + trans_hdr->len > user_msg->len) { + if (size_add(user_len, trans_hdr->len) > user_msg->len) { Fixes: 129776ac2e38 ("accel/qaic: Add control path") Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>Reviewed-by: Pranjal Ramajor Asha Kanojiya <quic_pkanojiy@xxxxxxxxxxx>
Applied to drm-misc-fixes -Jeff
