4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
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@xxxxxxxxx>
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
fs/ncpfs/ncplib_kernel.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/fs/ncpfs/ncplib_kernel.c
+++ b/fs/ncpfs/ncplib_kernel.c
@@ -980,6 +980,10 @@ 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);