[PATCH 4.19 029/338] NFSD: prevent integer overflow on 32 bit systems

[Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>]

From: Dan Carpenter <dan.carpenter@xxxxxxxxxx>

commit 23a9dbbe0faf124fc4c139615633b9d12a3a89ef upstream.

On a 32 bit system, the "len * sizeof(*p)" operation can have an
integer overflow.

Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 include/linux/sunrpc/xdr.h |    2 ++
 1 file changed, 2 insertions(+)

--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -509,6 +509,8 @@ xdr_stream_decode_uint32_array(struct xd
 
 	if (unlikely(xdr_stream_decode_u32(xdr, &len) < 0))
 		return -EBADMSG;
+	if (len > SIZE_MAX / sizeof(*p))
+		return -EBADMSG;
 	p = xdr_inline_decode(xdr, len * sizeof(*p));
 	if (unlikely(!p))
 		return -EBADMSG;