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>
