openssh: fix CVE-2019-16905

Backport a patch from upstream to fix CVE-2019-16905
https://github.com/openssh/openssh-portable/commit/a546b17bbaeb12beac4c9aeed56f74a42b18a93a

(From OE-Core rev: 8bd4b87071c073a0e4d265bc00df34684a355eff)

Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

2 files changed, 41 insertions, 0 deletions

diff --git a/meta/recipes-connectivity/openssh/openssh/0001-upstream-fix-integer-overflow-in-XMSS-private-key-pa.patch b/meta/recipes-connectivity/openssh/openssh/0001-upstream-fix-integer-overflow-in-XMSS-private-key-pa.patch
new file mode 100644
index 0000000000..3265be3485
--- /dev/null
+++ b/meta/recipes-connectivity/openssh/openssh/0001-upstream-fix-integer-overflow-in-XMSS-private-key-pa.patch
@@ -0,0 +1,40 @@
+From 2014fad3d28090b59d2f8a0971166c06e5fa6da6 Mon Sep 17 00:00:00 2001
+From: Hongxu Jia <hongxu.jia@windriver.com>
+Date: Fri, 18 Oct 2019 14:56:58 +0800
+Subject: [PATCH] upstream: fix integer overflow in XMSS private key parsing.
+
+Reported by Adam Zabrocki via SecuriTeam's SSH program.
+
+Note that this code is experimental and not compiled by default.
+
+ok markus@
+
+OpenBSD-Commit-ID: cd0361896d15e8a1bac495ac583ff065ffca2be1
+
+Signed-off-by: "djm@openbsd.org" <djm@openbsd.org>
+
+Upstream-Status: Backport [https://github.com/openssh/openssh-portable/commit/a546b17bbaeb12beac4c9aeed56f74a42b18a93a]
+CVE: CVE-2019-16905
+
+Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com>
+---
+ sshkey-xmss.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/sshkey-xmss.c b/sshkey-xmss.c
+index aaae702..c57681a 100644
+--- a/sshkey-xmss.c
++++ b/sshkey-xmss.c
+@@ -977,7 +977,8 @@ sshkey_xmss_decrypt_state(const struct sshkey *k, struct sshbuf *encoded,
+                goto out;
+        }
+        /* check that an appropriate amount of auth data is present */
+-       if (sshbuf_len(encoded) < encrypted_len + authlen) {
++       if (sshbuf_len(encoded) < authlen ||
++           sshbuf_len(encoded) - authlen < encrypted_len) {
+                r = SSH_ERR_INVALID_FORMAT;
+                goto out;
+        }
+-- 
+2.7.4
+
diff --git a/meta/recipes-connectivity/openssh/openssh_8.0p1.bb b/meta/recipes-connectivity/openssh/openssh_8.0p1.bb
index 01eaecd4ec..2ffbc9a95f 100644
--- a/meta/recipes-connectivity/openssh/openssh_8.0p1.bb
+++ b/meta/recipes-connectivity/openssh/openssh_8.0p1.bb
@@ -24,6 +24,7 @@ SRC_URI = "http://ftp.openbsd.org/pub/OpenBSD/OpenSSH/portable/openssh-${PV}.tar
            file://fix-potential-signed-overflow-in-pointer-arithmatic.patch \
            file://sshd_check_keys \
            file://add-test-support-for-busybox.patch \
+           file://0001-upstream-fix-integer-overflow-in-XMSS-private-key-pa.patch \
            "
 SRC_URI[md5sum] = "bf050f002fe510e1daecd39044e1122d"
 SRC_URI[sha256sum] = "bd943879e69498e8031eb6b7f44d08cdc37d59a7ab689aa0b437320c3481fd68"