CVE: nfs: fix stack-based buffer overflow in some nfs_handler reply helper functions

This patch adds a check to nfs_handler to fix buffer overflow for CVE-2019-14197,
CVE-2019-14200, CVE-2019-14201, CVE-2019-14202, CVE-2019-14203 and CVE-2019-14204.

Signed-off-by: Cheng Liu <liucheng32@huawei.com>
Reported-by: Fermín Serna <fermin@semmle.com>
Acked-by: Joe Hershberger <joe.hershberger@ni.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/net/nfs.c b/net/nfs.c
index d6a7f8e827..b7cf3b3a18 100644
--- a/net/nfs.c
+++ b/net/nfs.c
@@ -732,6 +732,9 @@ static void nfs_handler(uchar *pkt, unsigned dest, struct in_addr sip,
 
 	debug("%s\n", __func__);
 
+	if (len > sizeof(struct rpc_t))
+		return;
+
 	if (dest != nfs_our_port)
 		return;