From 0e6b3fc240007a2cec65d12dfa1e997cd9c638b5 Mon Sep 17 00:00:00 2001
From: glebius <glebius@ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f>
Date: Tue, 25 Oct 2016 17:11:11 +0000
Subject: [PATCH] Revised SA-16:15.  The initial patch didn't cover all
 possible overflows based on passing incorrect parameters to sysarch(2).

Security:	SA-16:15
Approved by:	so


git-svn-id: https://svn.freebsd.org/base/releng/10.2@307933 ccf9f872-aa2e-dd11-9fc8-001c23d0bc1f
---
 UPDATING                      | 4 ++++
 sys/amd64/amd64/sys_machdep.c | 5 ++++-
 sys/conf/newvers.sh           | 2 +-
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/UPDATING b/UPDATING
index 2471adf02..83145cad4 100644
--- a/UPDATING
+++ b/UPDATING
@@ -16,6 +16,10 @@ 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.
 
+20161025	p24	FreeBSD-SA-16:15.sysarch [revised]
+
+	Fix incorrect argument validation in sysarch(2). [SA-16:15]
+
 20161010	p23	FreeBSD-SA-16:29.bspatch
 			FreeBSD-SA-16:30.portsnap
 			FreeBSD-SA-16:31.libarchive
diff --git a/sys/amd64/amd64/sys_machdep.c b/sys/amd64/amd64/sys_machdep.c
index ff3bd3edc..5c8527279 100644
--- a/sys/amd64/amd64/sys_machdep.c
+++ b/sys/amd64/amd64/sys_machdep.c
@@ -617,6 +617,8 @@ amd64_set_ldt(td, uap, descs)
 		largest_ld = uap->start + uap->num;
 		if (largest_ld > max_ldt_segment)
 			largest_ld = max_ldt_segment;
+		if (largest_ld < uap->start)
+			return (EINVAL);
 		i = largest_ld - uap->start;
 		mtx_lock(&dt_lock);
 		bzero(&((struct user_segment_descriptor *)(pldt->ldt_base))
@@ -629,7 +631,8 @@ amd64_set_ldt(td, uap, descs)
 		/* verify range of descriptors to modify */
 		largest_ld = uap->start + uap->num;
 		if (uap->start >= max_ldt_segment ||
-		    largest_ld > max_ldt_segment)
+		    largest_ld > max_ldt_segment ||
+		    largest_ld < uap->start)
 			return (EINVAL);
 	}
 
diff --git a/sys/conf/newvers.sh b/sys/conf/newvers.sh
index c8220d022..697f5c467 100644
--- a/sys/conf/newvers.sh
+++ b/sys/conf/newvers.sh
@@ -32,7 +32,7 @@
 
 TYPE="FreeBSD"
 REVISION="10.2"
-BRANCH="RELEASE-p23"
+BRANCH="RELEASE-p24"
 if [ "X${BRANCH_OVERRIDE}" != "X" ]; then
 	BRANCH=${BRANCH_OVERRIDE}
 fi
-- 
2.42.0