[ovs-dev] [PATCH V2 08/10] datapath: fix data type in queue_gso_packets

[Greg Rose]

From: "Gustavo A. R. Silva" <garsilva at embeddedor.com>

Upstream commit:
    commit 2734166e89639c973c6e125ac8bcfc2d9db72b70
    Author: Gustavo A. R. Silva <garsilva at embeddedor.com>
    Date:   Sat Nov 25 13:14:40 2017 -0600

    net: openvswitch: datapath: fix data type in queue_gso_packets

    gso_type is being used in binary AND operations together with SKB_GSO_UDP.
    The issue is that variable gso_type is of type unsigned short and
    SKB_GSO_UDP expands to more than 16 bits:

    SKB_GSO_UDP = 1 << 16

    this makes any binary AND operation between gso_type and SKB_GSO_UDP to
    be always zero, hence making some code unreachable and likely causing
    undesired behavior.

    Fix this by changing the data type of variable gso_type to unsigned int.

    Addresses-Coverity-ID: 1462223
    Fixes: 0c19f846d582 ("net: accept UFO datagrams from tuntap and packet")
    Signed-off-by: Gustavo A. R. Silva <garsilva at embeddedor.com>
    Acked-by: Willem de Bruijn <willemb at google.com>
    Signed-off-by: David S. Miller <davem at davemloft.net>

While backporting this I found another couple of instances of the
same issue so I fixed them up as well.

Cc: Gustavo A. R. Silva <garsilva at embeddedor.com>
Signed-off-by: Greg Rose <gvrose8192 at gmail.com>
---
 datapath/datapath.c         | 2 +-
 datapath/linux/compat/stt.c | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/datapath/datapath.c b/datapath/datapath.c
index 38a453b..6ee507a 100644
--- a/datapath/datapath.c
+++ b/datapath/datapath.c
@@ -340,7 +340,7 @@ static int queue_gso_packets(struct datapath *dp, struct sk_buff *skb,
 				 uint32_t cutlen)
 {
 #ifdef HAVE_SKB_GSO_UDP
-	unsigned short gso_type = skb_shinfo(skb)->gso_type;
+	unsigned int gso_type = skb_shinfo(skb)->gso_type;
 	struct sw_flow_key later_key;
 #endif
 	struct sk_buff *segs, *nskb;
diff --git a/datapath/linux/compat/stt.c b/datapath/linux/compat/stt.c
index 66a97f2..2189476 100644
--- a/datapath/linux/compat/stt.c
+++ b/datapath/linux/compat/stt.c
@@ -1315,7 +1315,7 @@ static bool validate_checksum(struct sk_buff *skb)
 static bool set_offloads(struct sk_buff *skb)
 {
 	struct stthdr *stth = stt_hdr(skb);
-	unsigned short gso_type = 0;
+	unsigned int gso_type = 0;
 	int l3_header_size;
 	int l4_header_size;
 	u16 csum_offset;
-- 
1.8.3.1