CVE-2019-14194/CVE-2019-14198: nfs: fix unbounded memcpy with a failed length check...

This patch adds a check to rpc_pkt.u.reply.data at nfs_read_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 b7cf3b3a188cc7b051e26a1d9ec8869ac3da2682..11941fad1acfc0381e26fd119eb311afef949b16 100644 (file)
--- a/net/nfs.c
+++ b/net/nfs.c
@@ -701,6 +701,9 @@ static int nfs_read_reply(uchar *pkt, unsigned len)
                        &(rpc_pkt.u.reply.data[4 + nfsv3_data_offset]);
        }
 
+       if (((uchar *)&(rpc_pkt.u.reply.data[0]) - (uchar *)(&rpc_pkt) + rlen) > len)
+                       return -9999;
+
        if (store_block(data_ptr, nfs_offset, rlen))
                        return -9999;