gnu: linux-libre: Add fix for CVE-2016-0728.

* gnu/packages/patches/linux-libre-CVE-2016-0728.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.
* gnu/packages/linux.scm (linux-libre)[source]: Add patch.

gnu-system.am

 # GNU Guix --- Functional package management for GNU
 # Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
 # Copyright © 2013, 2014, 2015, 2016 Andreas Enge <andreas@enge.fr>
-# Copyright © 2013, 2014, 2015 Mark H Weaver <mhw@netris.org>
+# Copyright © 2013, 2014, 2015, 2016 Mark H Weaver <mhw@netris.org>
 #
 # This file is part of GNU Guix.
 #
@@ -565,6 +565,7 @@ dist_patch_DATA =						\
   gnu/packages/patches/libwmf-CVE-2015-4695.patch		\
   gnu/packages/patches/libwmf-CVE-2015-4696.patch		\
   gnu/packages/patches/libxslt-CVE-2015-7995.patch		\
+  gnu/packages/patches/linux-libre-CVE-2016-0728.patch		\
   gnu/packages/patches/lirc-localstatedir.patch			\
   gnu/packages/patches/libpthread-glibc-preparation.patch	\
   gnu/packages/patches/lm-sensors-hwmon-attrs.patch		\

gnu/packages/linux.scm

@@ -2,7 +2,7 @@
 ;;; Copyright © 2012, 2013, 2014, 2015 Ludovic Courtès <ludo@gnu.org>
 ;;; Copyright © 2013, 2014, 2015 Andreas Enge <andreas@enge.fr>
 ;;; Copyright © 2012 Nikita Karetnikov <nikita@karetnikov.org>
-;;; Copyright © 2014, 2015 Mark H Weaver <mhw@netris.org>
+;;; Copyright © 2014, 2015, 2016 Mark H Weaver <mhw@netris.org>
 ;;; Copyright © 2015 Federico Beffa <beffa@fbengineering.ch>
 ;;; Copyright © 2015 Taylan Ulrich Bayırlı/Kammer <taylanbayirli@gmail.com>
 ;;; Copyright © 2015 Efraim Flashner <efraim@flashner.co.il>
@@ -286,7 +286,9 @@ (define-public linux-libre
              (uri (linux-libre-urls version))
              (sha256
               (base32
-               "1839xsaifs7vvyblzin8jps0gqi10xmz1l9p4x0j27vmdj39jgpm"))))
+               "1839xsaifs7vvyblzin8jps0gqi10xmz1l9p4x0j27vmdj39jgpm"))
+             (patches
+              (list (search-patch "linux-libre-CVE-2016-0728.patch")))))
     (build-system gnu-build-system)
     (supported-systems '("x86_64-linux" "i686-linux"))
     (native-inputs `(("perl" ,perl)

gnu/packages/patches/linux-libre-CVE-2016-0728.patch

+Copied from
+https://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/patch/?id=23567fd052a9abb6d67fe8e7a9ccdd9800a540f2
+
+From 23567fd052a9abb6d67fe8e7a9ccdd9800a540f2 Mon Sep 17 00:00:00 2001
+From: Yevgeny Pats <yevgeny@perception-point.io>
+Date: Tue, 19 Jan 2016 22:09:04 +0000
+Subject: KEYS: Fix keyring ref leak in join_session_keyring()
+
+This fixes CVE-2016-0728.
+
+If a thread is asked to join as a session keyring the keyring that's already
+set as its session, we leak a keyring reference.
+
+This can be tested with the following program:
+
+	#include <stddef.h>
+	#include <stdio.h>
+	#include <sys/types.h>
+	#include <keyutils.h>
+
+	int main(int argc, const char *argv[])
+	{
+		int i = 0;
+		key_serial_t serial;
+
+		serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
+				"leaked-keyring");
+		if (serial < 0) {
+			perror("keyctl");
+			return -1;
+		}
+
+		if (keyctl(KEYCTL_SETPERM, serial,
+			   KEY_POS_ALL | KEY_USR_ALL) < 0) {
+			perror("keyctl");
+			return -1;
+		}
+
+		for (i = 0; i < 100; i++) {
+			serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING,
+					"leaked-keyring");
+			if (serial < 0) {
+				perror("keyctl");
+				return -1;
+			}
+		}
+
+		return 0;
+	}
+
+If, after the program has run, there something like the following line in
+/proc/keys:
+
+3f3d898f I--Q---   100 perm 3f3f0000     0     0 keyring   leaked-keyring: empty
+
+with a usage count of 100 * the number of times the program has been run,
+then the kernel is malfunctioning.  If leaked-keyring has zero usages or
+has been garbage collected, then the problem is fixed.
+
+Reported-by: Yevgeny Pats <yevgeny@perception-point.io>
+Signed-off-by: David Howells <dhowells@redhat.com>
+Acked-by: Don Zickus <dzickus@redhat.com>
+Acked-by: Prarit Bhargava <prarit@redhat.com>
+Acked-by: Jarod Wilson <jarod@redhat.com>
+Signed-off-by: James Morris <james.l.morris@oracle.com>
+---
+ security/keys/process_keys.c | 1 +
+ 1 file changed, 1 insertion(+)
+
+diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c
+index a3f85d2..e6d50172 100644
+--- a/security/keys/process_keys.c
++++ b/security/keys/process_keys.c
+@@ -794,6 +794,7 @@ long join_session_keyring(const char *name)
+ 		ret = PTR_ERR(keyring);
+ 		goto error2;
+ 	} else if (keyring == new->session_keyring) {
++		key_put(keyring);
+ 		ret = 0;
+ 		goto error2;
+ 	}
+-- 
+cgit v0.12
+