From e5ca3a45381e3b2bcc392bc003966103c376acb7 Mon Sep 17 00:00:00 2001
From: gordon <gordon@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Wed, 7 Mar 2018 05:53:35 +0000
Subject: [PATCH] Fix ipsec validation and use-after-free. [SA-18:01.ipsec]

Approved by:	so
Security:	FreeBSD-SA-18:01.ipsec
Security:	CVE-2018-6916


git-svn-id: svn://svn.freebsd.org/base/releng/10.3@330566 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 UPDATING                | 13 +++++++++++++
 sys/conf/newvers.sh     |  2 +-
 sys/netipsec/xform_ah.c | 15 ++++++++++++++-
 3 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/UPDATING b/UPDATING
index 7f1e11bd4..bc6152842 100644
--- a/UPDATING
+++ b/UPDATING
@@ -16,6 +16,19 @@ from older versions of FreeBSD, try WITHOUT_CLANG to bootstrap to the tip of
 stable/10, and then rebuild without this option. The bootstrap process from
 older version of current is a bit fragile.
 
+20180307	p27	FreeBSD-SA-18:01.ipsec
+			FreeBSD-SA-18:02.ntp
+			FreeBSD-EN-18:01.tzdata
+			FreeBSD-EN-18:02.file
+
+	Fix ipsec validation and use-after-free. [SA-18:01.ipsec]
+
+	Fix multiple vulnerabilities in ntp. [SA-18:02.ntp]
+
+	Update timezone database information. [EN-18:01.tzdata]
+
+	Update file(1) to new version with security update. [EN-18:02.file]
+
 20171209	p26	FreeBSD-SA-17:12.openssl
 
 	Fix OpenSSL error state vulnerability.
diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index ea4ab58c1..1a76473a3 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -32,7 +32,7 @@
 
 TYPE="FreeBSD"
 REVISION="10.3"
-BRANCH="RELEASE-p26"
+BRANCH="RELEASE-p27"
 if [ "X${BRANCH_OVERRIDE}" != "X" ]; then
 	BRANCH=${BRANCH_OVERRIDE}
 fi
diff --git a/sys/netipsec/xform_ah.c b/sys/netipsec/xform_ah.c
index afa452cac..3f678414c 100644
--- a/sys/netipsec/xform_ah.c
+++ b/sys/netipsec/xform_ah.c
@@ -615,6 +615,16 @@ ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 		m_freem(m);
 		return EACCES;
 	}
+	if (skip + authsize + rplen > m->m_pkthdr.len) {
+		DPRINTF(("%s: bad mbuf length %u (expecting %lu)"
+		    " for packet in SA %s/%08lx\n", __func__,
+		    m->m_pkthdr.len, (u_long) (skip + authsize + rplen),
+		    ipsec_address(&sav->sah->saidx.dst, buf, sizeof(buf)),
+		    (u_long) ntohl(sav->spi)));
+		AHSTAT_INC(ahs_badauthl);
+		error = EACCES;
+		goto bad;
+	}
 	AHSTAT_ADD(ahs_ibytes, m->m_pkthdr.len - skip - hl);
 
 	/* Get crypto descriptors. */
@@ -680,6 +690,9 @@ ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 		/* Zeroize the authenticator on the packet. */
 		m_copyback(m, skip + rplen, authsize, ipseczeroes);
 
+		/* Save ah_nxt, since ah pointer can become invalid after "massage" */
+		hl = ah->ah_nxt;
+
 		/* "Massage" the packet headers for crypto processing. */
 		error = ah_massage_headers(&m, sav->sah->saidx.dst.sa.sa_family,
 		    skip, ahx->type, 0);
@@ -704,7 +717,7 @@ ah_input(struct mbuf *m, struct secasvar *sav, int skip, int protoff)
 	tc->tc_spi = sav->spi;
 	tc->tc_dst = sav->sah->saidx.dst;
 	tc->tc_proto = sav->sah->saidx.proto;
-	tc->tc_nxt = ah->ah_nxt;
+	tc->tc_nxt = hl;
 	tc->tc_protoff = protoff;
 	tc->tc_skip = skip;
 	tc->tc_ptr = (caddr_t) mtag; /* Save the mtag we've identified. */
-- 
2.42.0