From: liucheng (G) <liucheng32@huawei.com>
Date: Thu, 29 Aug 2019 13:48:02 +0000 (+0000)
Subject: CVE-2019-14196: nfs: fix unbounded memcpy with a failed length check at nfs_lookup_reply
X-Git-Tag: v2019.10-rc4~22^2~3
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=5d14ee4e53a81055d34ba280cb8fd90330f22a96;p=oweals%2Fu-boot.git

CVE-2019-14196: nfs: fix unbounded memcpy with a failed length check at nfs_lookup_reply

This patch adds a check to rpc_pkt.u.reply.data at nfs_lookup_reply.

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

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);
 	}