In the Linux kernel, the following vulnerability has been resolved:
accel/qaic: tighten bounds checking in decode_message()
Copy the bounds checking from encode_message() to decode_message().
This patch addresses the following concerns. Ensure that there is enough space for at least one header so that we dont have a negative size later.
if (msg_hdr_len < sizeof(*trans_hdr))
Ensure that we have enough space to read the next header from the msg->data.
if (msg_len > msg_hdr_len - sizeof(*trans_hdr))
return -EINVAL;
Check that the trans_hdr->len is not below the minimum size:
if (hdr_len < sizeof(*trans_hdr))
This minimum check ensures that we dont corrupt memory in decode_passthrough() when we do.
memcpy(out_trans->data, in_trans->data, len - sizeof(in_trans->hdr));
And finally, use size_add() to prevent an integer overflow:
if (size_add(msg_len, hdr_len) > msg_hdr_len)