CVE-2016-8858: Unregister the KEXINIT handler after message has been received (closes: #841884).

5 files changed, 41 insertions, 3 deletions

diff --git a/debian/.git-dpm b/debian/.git-dpm
index 1532e846b..1f74d7567 100644
--- a/debian/.git-dpm
+++ b/debian/.git-dpm
@@ -1,6 +1,6 @@
 # see git-dpm(1) from git-dpm package
-4c914ccd85bbf391c4dc61b85e3c178fef465e3f
-4c914ccd85bbf391c4dc61b85e3c178fef465e3f
+b139635512b1af75e82252c0c71ac66e08b78774
+b139635512b1af75e82252c0c71ac66e08b78774
 a8ed8d256b2e2c05b0c15565a7938028c5192277
 a8ed8d256b2e2c05b0c15565a7938028c5192277
 openssh_7.3p1.orig.tar.gz
diff --git a/debian/changelog b/debian/changelog
index aed040e05..95d55cb6d 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,6 +1,8 @@
-openssh (1:7.3p1-2) UNRELEASED; urgency=medium
+openssh (1:7.3p1-2) UNRELEASED; urgency=high
 
   * Rewrite debian/copyright using copyright-format 1.0.
+  * CVE-2016-8858: Unregister the KEXINIT handler after message has been
+    received (closes: #841884).
 
  -- Colin Watson <cjwatson@debian.org>  Sun, 14 Aug 2016 12:15:53 +0100
 
diff --git a/debian/patches/series b/debian/patches/series
index e5821f627..a968a036d 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -25,3 +25,4 @@ gnome-ssh-askpass2-icon.patch
 sigstop.patch
 systemd-readiness.patch
 debian-config.patch
+unregister-kexinit.patch
diff --git a/debian/patches/unregister-kexinit.patch b/debian/patches/unregister-kexinit.patch
new file mode 100644
index 000000000..48da43273
--- /dev/null
+++ b/debian/patches/unregister-kexinit.patch
@@ -0,0 +1,34 @@
+From b139635512b1af75e82252c0c71ac66e08b78774 Mon Sep 17 00:00:00 2001
+From: "markus@openbsd.org" <markus@openbsd.org>
+Date: Mon, 10 Oct 2016 19:28:48 +0000
+Subject: upstream commit
+
+Unregister the KEXINIT handler after message has been
+received. Otherwise an unauthenticated peer can repeat the KEXINIT and cause
+allocation of up to 128MB -- until the connection is closed. Reported by
+shilei-c at 360.cn
+
+Upstream-ID: 43649ae12a27ef94290db16d1a98294588b75c05
+
+Origin: https://anongit.mindrot.org/openssh.git/commit/?id=ec165c392ca54317dbe3064a8c200de6531e89ad
+Bug-Debian: https://bugs.debian.org/841884
+Bug-Fedora: https://bugzilla.redhat.com/show_bug.cgi?id=1384860
+Last-Update: 2016-10-24
+
+Patch-Name: unregister-kexinit.patch
+---
+ kex.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/kex.c b/kex.c
+index c17d652..7ab72ba 100644
+--- a/kex.c
++++ b/kex.c
+@@ -488,6 +488,7 @@ kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
+        if (kex == NULL)
+                return SSH_ERR_INVALID_ARGUMENT;
+ 
++       ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, NULL);
+        ptr = sshpkt_ptr(ssh, &dlen);
+        if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
+                return r;
diff --git a/kex.c b/kex.c
index c17d652c9..7ab72ba19 100644
--- a/kex.c
+++ b/kex.c
@@ -488,6 +488,7 @@ kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
         if (kex == NULL)
                 return SSH_ERR_INVALID_ARGUMENT;
 
+        ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, NULL);
         ptr = sshpkt_ptr(ssh, &dlen);
         if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
                 return r;