From 5d14ee4e53a81055d34ba280cb8fd90330f22a96 Mon Sep 17 00:00:00 2001 From: "liucheng (G)" Date: Thu, 29 Aug 2019 13:48:02 +0000 Subject: [PATCH] CVE-2019-14196: nfs: fix unbounded memcpy with a failed length check at nfs_lookup_reply MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit This patch adds a check to rpc_pkt.u.reply.data at nfs_lookup_reply. Signed-off-by: Cheng Liu Reported-by: Fermín Serna Acked-by: Joe Hershberger --- net/nfs.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/nfs.c b/net/nfs.c index 915acd95cf..89952aeb66 100644 --- a/net/nfs.c +++ b/net/nfs.c @@ -566,11 +566,15 @@ static int nfs_lookup_reply(uchar *pkt, unsigned len) } if (supported_nfs_versions & NFSV2_FLAG) { + if (((uchar *)&(rpc_pkt.u.reply.data[0]) - (uchar *)(&rpc_pkt) + NFS_FHSIZE) > len) + return -NFS_RPC_DROP; memcpy(filefh, rpc_pkt.u.reply.data + 1, NFS_FHSIZE); } else { /* NFSV3_FLAG */ filefh3_length = ntohl(rpc_pkt.u.reply.data[1]); if (filefh3_length > NFS3_FHSIZE) filefh3_length = NFS3_FHSIZE; + if (((uchar *)&(rpc_pkt.u.reply.data[0]) - (uchar *)(&rpc_pkt) + filefh3_length) > len) + return -NFS_RPC_DROP; memcpy(filefh, rpc_pkt.u.reply.data + 2, filefh3_length); } -- 2.25.1