[dpdk-stable] patch 'ip_frag: check fragment length of incoming packet' has been queued to stable release 18.08.1

[Kevin Traynor]

Hi,

FYI, your patch has been queued to stable release 18.08.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 11/29/18. 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. If the code is different (ie: not only metadata diffs), due for example to
a change in context or macro names, please double check it.

Thanks.

Kevin Traynor

---
>From 8110ef175034b7a54ff2dfab80aabbf0fc1a7f22 Mon Sep 17 00:00:00 2001
From: Konstantin Ananyev <konstantin.ananyev at intel.com>
Date: Mon, 5 Nov 2018 12:18:57 +0000
Subject: [PATCH] ip_frag: check fragment length of incoming packet

[ upstream commit 7f0983ee331c9f08dabdb5b7f555ddf399003dcf ]

Under some conditions ill-formed fragments might cause
reassembly code to corrupt mbufs and/or crash.
Let say the following fragments sequence:
<ofs=0,len=100, flags=MF>
<ofs=96,len=100, flags=MF>
<ofs=200,len=0,flags=MF>
<ofs=200,len=100,flags=0>
can trigger the problem.
To overcome such situation, added check that fragment length
of incoming value is greater than zero.

Fixes: 601e279df074 ("ip_frag: move fragmentation/reassembly headers into a library")
Fixes: 4f1a8f633862 ("ip_frag: add IPv6 reassembly")

Reported-by: Ryan E Hall <ryan.e.hall at intel.com>
Reported-by: Alexander V Gutkin <alexander.v.gutkin at intel.com>
Signed-off-by: Konstantin Ananyev <konstantin.ananyev at intel.com>
---
 lib/librte_ip_frag/rte_ipv4_reassembly.c | 22 +++++++++++++------
 lib/librte_ip_frag/rte_ipv6_reassembly.c | 28 +++++++++++++++++-------
 2 files changed, 35 insertions(+), 15 deletions(-)

diff --git a/lib/librte_ip_frag/rte_ipv4_reassembly.c b/lib/librte_ip_frag/rte_ipv4_reassembly.c
index 4956b99ea..1029b7abc 100644
--- a/lib/librte_ip_frag/rte_ipv4_reassembly.c
+++ b/lib/librte_ip_frag/rte_ipv4_reassembly.c
@@ -37,6 +37,9 @@ ipv4_frag_reassemble(struct ip_frag_pkt *fp)
 			if(fp->frags[i].ofs + fp->frags[i].len == ofs) {
 
+				RTE_ASSERT(curr_idx != i);
+
 				/* adjust start of the last fragment data. */
-				rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
+				rte_pktmbuf_adj(m,
+					(uint16_t)(m->l2_len + m->l3_len));
 				rte_pktmbuf_chain(fp->frags[i].mb, m);
 
@@ -97,12 +100,12 @@ ipv4_frag_reassemble(struct ip_frag_pkt *fp)
 struct rte_mbuf *
 rte_ipv4_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
-		struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms,
-		struct ipv4_hdr *ip_hdr)
+	struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms,
+	struct ipv4_hdr *ip_hdr)
 {
 	struct ip_frag_pkt *fp;
 	struct ip_frag_key key;
 	const unaligned_uint64_t *psd;
-	uint16_t ip_len;
 	uint16_t flag_offset, ip_ofs, ip_flag;
+	int32_t ip_len;
 
 	flag_offset = rte_be_to_cpu_16(ip_hdr->fragment_offset);
@@ -117,10 +120,9 @@ rte_ipv4_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 
 	ip_ofs *= IPV4_HDR_OFFSET_UNITS;
-	ip_len = (uint16_t)(rte_be_to_cpu_16(ip_hdr->total_length) -
-		mb->l3_len);
+	ip_len = rte_be_to_cpu_16(ip_hdr->total_length) - mb->l3_len;
 
 	IP_FRAG_LOG(DEBUG, "%s:%d:\n"
 		"mbuf: %p, tms: %" PRIu64
-		", key: <%" PRIx64 ", %#x>, ofs: %u, len: %u, flags: %#x\n"
+		", key: <%" PRIx64 ", %#x>, ofs: %u, len: %d, flags: %#x\n"
 		"tbl: %p, max_cycles: %" PRIu64 ", entry_mask: %#x, "
 		"max_entries: %u, use_entries: %u\n\n",
@@ -130,4 +132,10 @@ rte_ipv4_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 		tbl->use_entries);
 
+	/* check that fragment length is greater then zero. */
+	if (ip_len <= 0) {
+		IP_FRAG_MBUF2DR(dr, mb);
+		return NULL;
+	}
+
 	/* try to find/add entry into the fragment's table. */
 	if ((fp = ip_frag_find(tbl, dr, &key, tms)) == NULL) {
diff --git a/lib/librte_ip_frag/rte_ipv6_reassembly.c b/lib/librte_ip_frag/rte_ipv6_reassembly.c
index db249fe60..855e3f740 100644
--- a/lib/librte_ip_frag/rte_ipv6_reassembly.c
+++ b/lib/librte_ip_frag/rte_ipv6_reassembly.c
@@ -60,6 +60,9 @@ ipv6_frag_reassemble(struct ip_frag_pkt *fp)
 			if (fp->frags[i].ofs + fp->frags[i].len == ofs) {
 
+				RTE_ASSERT(curr_idx != i);
+
 				/* adjust start of the last fragment data. */
-				rte_pktmbuf_adj(m, (uint16_t)(m->l2_len + m->l3_len));
+				rte_pktmbuf_adj(m,
+					(uint16_t)(m->l2_len + m->l3_len));
 				rte_pktmbuf_chain(fp->frags[i].mb, m);
 
@@ -136,10 +139,11 @@ ipv6_frag_reassemble(struct ip_frag_pkt *fp)
 struct rte_mbuf *
 rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
-		struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms,
-		struct ipv6_hdr *ip_hdr, struct ipv6_extension_fragment *frag_hdr)
+	struct rte_ip_frag_death_row *dr, struct rte_mbuf *mb, uint64_t tms,
+	struct ipv6_hdr *ip_hdr, struct ipv6_extension_fragment *frag_hdr)
 {
 	struct ip_frag_pkt *fp;
 	struct ip_frag_key key;
-	uint16_t ip_len, ip_ofs;
+	uint16_t ip_ofs;
+	int32_t ip_len;
 
 	rte_memcpy(&key.src_dst[0], ip_hdr->src_addr, 16);
@@ -152,7 +156,8 @@ rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 
 	/*
-	 * as per RFC2460, payload length contains all extension headers as well.
-	 * since we don't support anything but frag headers, this is what we remove
-	 * from the payload len.
+	 * as per RFC2460, payload length contains all extension headers
+	 * as well.
+	 * since we don't support anything but frag headers,
+	 * this is what we remove from the payload len.
 	 */
 	ip_len = rte_be_to_cpu_16(ip_hdr->payload_len) - sizeof(*frag_hdr);
@@ -160,5 +165,6 @@ rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 	IP_FRAG_LOG(DEBUG, "%s:%d:\n"
 		"mbuf: %p, tms: %" PRIu64
-		", key: <" IPv6_KEY_BYTES_FMT ", %#x>, ofs: %u, len: %u, flags: %#x\n"
+		", key: <" IPv6_KEY_BYTES_FMT ", %#x>, "
+		"ofs: %u, len: %d, flags: %#x\n"
 		"tbl: %p, max_cycles: %" PRIu64 ", entry_mask: %#x, "
 		"max_entries: %u, use_entries: %u\n\n",
@@ -169,4 +175,10 @@ rte_ipv6_frag_reassemble_packet(struct rte_ip_frag_tbl *tbl,
 		tbl->use_entries);
 
+	/* check that fragment length is greater then zero. */
+	if (ip_len <= 0) {
+		IP_FRAG_MBUF2DR(dr, mb);
+		return NULL;
+	}
+
 	/* try to find/add entry into the fragment's table. */
 	fp = ip_frag_find(tbl, dr, &key, tms);
-- 
2.19.0

---
  Diff of the applied patch vs upstream commit (please double-check if non-empty:
---
--- -	2018-11-23 10:22:55.580563827 +0000
+++ 0051-ip_frag-check-fragment-length-of-incoming-packet.patch	2018-11-23 10:22:54.000000000 +0000
@@ -1,8 +1,10 @@
-From 7f0983ee331c9f08dabdb5b7f555ddf399003dcf Mon Sep 17 00:00:00 2001
+From 8110ef175034b7a54ff2dfab80aabbf0fc1a7f22 Mon Sep 17 00:00:00 2001
 From: Konstantin Ananyev <konstantin.ananyev at intel.com>
 Date: Mon, 5 Nov 2018 12:18:57 +0000
 Subject: [PATCH] ip_frag: check fragment length of incoming packet
 
+[ upstream commit 7f0983ee331c9f08dabdb5b7f555ddf399003dcf ]
+
 Under some conditions ill-formed fragments might cause
 reassembly code to corrupt mbufs and/or crash.
 Let say the following fragments sequence:
@@ -16,7 +18,6 @@
 
 Fixes: 601e279df074 ("ip_frag: move fragmentation/reassembly headers into a library")
 Fixes: 4f1a8f633862 ("ip_frag: add IPv6 reassembly")
-Cc: stable at dpdk.org
 
 Reported-by: Ryan E Hall <ryan.e.hall at intel.com>
 Reported-by: Alexander V Gutkin <alexander.v.gutkin at intel.com>