staging: ncpfs: memory corruption in ncp_read_kernel()

If the server is malicious then *bytes_read could be larger than the
size of the "target" buffer.  It would lead to memory corruption when we
do the memcpy().

Reported-by: Dr Silvio Cesare of InfoSect <Silvio Cesare <silvio.cesare@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Dan Carpenter 2018-03-19 14:07:45 +03:00 committed by Greg Kroah-Hartman
parent b769949981
commit 4c41aa24ba
1 changed files with 4 additions and 0 deletions

View File

@ -981,6 +981,10 @@ ncp_read_kernel(struct ncp_server *server, const char *file_id,
goto out;
}
*bytes_read = ncp_reply_be16(server, 0);
if (*bytes_read > to_read) {
result = -EINVAL;
goto out;
}
source = ncp_reply_data(server, 2 + (offset & 1));
memcpy(target, source, *bytes_read);