* [PATCH] ncpfs: memory corruption in ncp_read_kernel()
[not found] <CA+ygN1LiXW3uNuMS-eRv5Y_WJNyyr77+Rgycec4Y-Ju2VGrNWA@mail.gmail.com>
@ 2018-03-19 11:07 ` Dan Carpenter
2018-03-19 13:56 ` Greg Kroah-Hartman
0 siblings, 1 reply; 2+ messages in thread
From: Dan Carpenter @ 2018-03-19 11:07 UTC (permalink / raw)
To: Petr Vandrovec
Cc: devel, security, Greg Kroah-Hartman, netdev, Philippe Ombredanne,
Thomas Gleixner, David S. Miller
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>
diff --git a/drivers/staging/ncpfs/ncplib_kernel.c b/drivers/staging/ncpfs/ncplib_kernel.c
index 804adfebba2f..3e047eb4cc7c 100644
--- a/drivers/staging/ncpfs/ncplib_kernel.c
+++ b/drivers/staging/ncpfs/ncplib_kernel.c
@@ -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);
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ncpfs: memory corruption in ncp_read_kernel()
2018-03-19 11:07 ` [PATCH] ncpfs: memory corruption in ncp_read_kernel() Dan Carpenter
@ 2018-03-19 13:56 ` Greg Kroah-Hartman
0 siblings, 0 replies; 2+ messages in thread
From: Greg Kroah-Hartman @ 2018-03-19 13:56 UTC (permalink / raw)
To: Dan Carpenter
Cc: devel, security, netdev, Philippe Ombredanne, Thomas Gleixner,
Petr Vandrovec, David S. Miller
On Mon, Mar 19, 2018 at 02:07:45PM +0300, Dan Carpenter wrote:
> 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>
>
> diff --git a/drivers/staging/ncpfs/ncplib_kernel.c b/drivers/staging/ncpfs/ncplib_kernel.c
> index 804adfebba2f..3e047eb4cc7c 100644
> --- a/drivers/staging/ncpfs/ncplib_kernel.c
> +++ b/drivers/staging/ncpfs/ncplib_kernel.c
Ugh, I have like 2 more months before I delete this code :)
Anyway, nice find, and fix, I'll go queue it up now, thanks.
greg k-h
^ permalink raw reply [flat|nested] 2+ messages in thread
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[not found] <CA+ygN1LiXW3uNuMS-eRv5Y_WJNyyr77+Rgycec4Y-Ju2VGrNWA@mail.gmail.com>
2018-03-19 11:07 ` [PATCH] ncpfs: memory corruption in ncp_read_kernel() Dan Carpenter
2018-03-19 13:56 ` Greg Kroah-Hartman
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