[dpdk-stable] patch 'net/tap: add buffer overflow checks before checksum' has been queued to LTS release 18.11.1

[Kevin Traynor]

Hi,

FYI, your patch has been queued to LTS release 18.11.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 01/11/19. So please
shout if anyone has objections.

Also note that after the patch there's a diff of the upstream commit vs the
patch applied to the branch. This will indicate if there was any rebasing
needed to apply to the stable branch. If there were code changes for rebasing
(ie: not only metadata diffs), please double check that the rebase was
correctly done.

Thanks.

Kevin Traynor

---
>From 8bfda00f4cc63d61cbb36dfc4fb30d3374821c6b Mon Sep 17 00:00:00 2001
From: Bruce Richardson <bruce.richardson at intel.com>
Date: Mon, 17 Dec 2018 15:50:05 +0000
Subject: [PATCH] net/tap: add buffer overflow checks before checksum

[ upstream commit 1168a4fd193c3bf981c4889cba150a7bb4c1d169 ]

The checksum calculation APIs take only the packet headers pointers as
parameters, so they assume that the lengths reported in those headers
are correct. However, a malicious packet could claim to be far larger
than it is, so we need to check the header lengths in the driver before
calling the checksum API.

A better fix would be to allow the lengths to be passed into the API
function, but that would be an API break, so fixing in TAP driver for
now.

Fixes: 8ae3023387e9 ("net/tap: add Rx/Tx checksum offload support")

Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>
Acked-by: Keith Wiles <keith.wiles at intel.com>
---
 drivers/net/tap/rte_eth_tap.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/drivers/net/tap/rte_eth_tap.c b/drivers/net/tap/rte_eth_tap.c
index 49afd38dd..0ec030bef 100644
--- a/drivers/net/tap/rte_eth_tap.c
+++ b/drivers/net/tap/rte_eth_tap.c
@@ -282,4 +282,10 @@ tap_verify_csum(struct rte_mbuf *mbuf)
 		if (unlikely(l2_len + l3_len > rte_pktmbuf_data_len(mbuf)))
 			return;
+		/* check that the total length reported by header is not
+		 * greater than the total received size
+		 */
+		if (l2_len + rte_be_to_cpu_16(iph->total_length) >
+				rte_pktmbuf_data_len(mbuf))
+			return;
 
 		cksum = ~rte_raw_cksum(iph, l3_len);
@@ -288,5 +294,13 @@ tap_verify_csum(struct rte_mbuf *mbuf)
 			PKT_RX_IP_CKSUM_GOOD;
 	} else if (l3 == RTE_PTYPE_L3_IPV6) {
+		struct ipv6_hdr *iph = l3_hdr;
+
 		l3_len = sizeof(struct ipv6_hdr);
+		/* check that the total length reported by header is not
+		 * greater than the total received size
+		 */
+		if (l2_len + l3_len + rte_be_to_cpu_16(iph->payload_len) >
+				rte_pktmbuf_data_len(mbuf))
+			return;
 	} else {
 		/* IPv6 extensions are not supported */
-- 
2.19.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2019-01-04 13:23:08.980683763 +0000
+++ 0063-net-tap-add-buffer-overflow-checks-before-checksum.patch	2019-01-04 13:23:07.000000000 +0000
@@ -1,8 +1,10 @@
-From 1168a4fd193c3bf981c4889cba150a7bb4c1d169 Mon Sep 17 00:00:00 2001
+From 8bfda00f4cc63d61cbb36dfc4fb30d3374821c6b Mon Sep 17 00:00:00 2001
 From: Bruce Richardson <bruce.richardson at intel.com>
 Date: Mon, 17 Dec 2018 15:50:05 +0000
 Subject: [PATCH] net/tap: add buffer overflow checks before checksum
 
+[ upstream commit 1168a4fd193c3bf981c4889cba150a7bb4c1d169 ]
+
 The checksum calculation APIs take only the packet headers pointers as
 parameters, so they assume that the lengths reported in those headers
 are correct. However, a malicious packet could claim to be far larger
@@ -14,7 +16,6 @@
 now.
 
 Fixes: 8ae3023387e9 ("net/tap: add Rx/Tx checksum offload support")
-Cc: stable at dpdk.org
 
 Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
 Reviewed-by: Ferruh Yigit <ferruh.yigit at intel.com>