4.14-stable review patch. If anyone has any objections, please let me know.
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From: Dan Carpenter dan.carpenter@oracle.com
commit 4c41aa24baa4ed338241d05494f2c595c885af8f upstream.
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
--- fs/ncpfs/ncplib_kernel.c | 4 ++++ 1 file changed, 4 insertions(+)
--- a/fs/ncpfs/ncplib_kernel.c +++ b/fs/ncpfs/ncplib_kernel.c @@ -981,6 +981,10 @@ ncp_read_kernel(struct ncp_server *serve 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);