01/01: gnu: openssh: Fix CVE-2016-8858.

[Leo Famulari]

lfam pushed a commit to branch master
in repository guix.

commit c645cef7da813ca305a9adeab08f34e925e560cc
Author: Leo Famulari <address@hidden>
Date:   Tue Oct 18 23:37:25 2016 -0400

    gnu: openssh: Fix CVE-2016-8858.
    
    * gnu/packages/patches/openssh-memory-exhaustion.patch: New file.
    * gnu/local.mk (dist_patch_DATA): Add it.
    * gnu/packages/ssh.scm (openssh)[source]: Use it.
---
 gnu/local.mk                                       |    1 +
 .../patches/openssh-memory-exhaustion.patch        |   39 ++++++++++++++++++++
 gnu/packages/ssh.scm                               |    1 +
 3 files changed, 41 insertions(+)

diff --git a/gnu/local.mk b/gnu/local.mk
index 18ba0c2..76fd64d 100644
--- a/gnu/local.mk
+++ b/gnu/local.mk
@@ -734,6 +734,7 @@ dist_patch_DATA =                                           
\
   %D%/packages/patches/openjpeg-CVE-2016-5157.patch            \
   %D%/packages/patches/openjpeg-CVE-2016-7163.patch            \
   %D%/packages/patches/openjpeg-use-after-free-fix.patch       \
+  %D%/packages/patches/openssh-memory-exhaustion.patch         \
   %D%/packages/patches/openssl-runpath.patch                   \
   %D%/packages/patches/openssl-1.1.0-c-rehash-in.patch         \
   %D%/packages/patches/openssl-c-rehash-in.patch               \
diff --git a/gnu/packages/patches/openssh-memory-exhaustion.patch 
b/gnu/packages/patches/openssh-memory-exhaustion.patch
new file mode 100644
index 0000000..91fe294
--- /dev/null
+++ b/gnu/packages/patches/openssh-memory-exhaustion.patch
@@ -0,0 +1,39 @@
+Fix a memory exhaustion bug in the key exchange, whereby an unauthenticated 
user
+could potentially consume 38400 MB of memory on the server:
+
+http://seclists.org/oss-sec/2016/q4/185
+
+Patch adapted from upstream source repository:
+
+https://github.com/openssh/openssh-portable/commit/ec165c392ca54317dbe3064a8c200de6531e89ad
+
+From ec165c392ca54317dbe3064a8c200de6531e89ad Mon Sep 17 00:00:00 2001
+From: "address@hidden" <address@hidden>
+Date: Mon, 10 Oct 2016 19:28:48 +0000
+Subject: [PATCH] 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
+---
+ kex.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/kex.c b/kex.c
+index 3f97f8c..6a94bc5 100644
+--- a/kex.c
++++ b/kex.c
+@@ -481,6 +481,7 @@ 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;
+-- 
+2.10.1
+
diff --git a/gnu/packages/ssh.scm b/gnu/packages/ssh.scm
index 9fd1506..af5aae1 100644
--- a/gnu/packages/ssh.scm
+++ b/gnu/packages/ssh.scm
@@ -121,6 +121,7 @@ a server that supports the SSH-2 protocol.")
                                         tail)
                          (string-append 
"http://ftp2.fr.openbsd.org/pub/OpenBSD/OpenSSH/portable/";
                                         tail))))
+            (patches (search-patches "openssh-memory-exhaustion.patch"))
             (sha256 (base32
                      "1k5y1wi29d47cgizbryxrhc1fbjsba2x8l5mqfa9b9nadnd9iyrz"))))
    (build-system gnu-build-system)