NFSD: prevent integer overflow on 32 bit systems

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

Cc: stable@vger.kernel.org
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>

diff --git a/include/linux/sunrpc/xdr.h b/include/linux/sunrpc/xdr.h
index b519609af1d020fa3676a59d652a6b9dcfe7d58f..4417f667c757e5e16be9d82b8696029687d30773 100644 (file)
--- a/include/linux/sunrpc/xdr.h
+++ b/include/linux/sunrpc/xdr.h
@@ -731,6 +731,8 @@ xdr_stream_decode_uint32_array(struct xdr_stream *xdr,
 
        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;