linux-libre-rt-4.1.15_gnu.rt17-2: fix CVE-2016-0728 - FS#47820 -> https://bugs.archlinux.org/task/47820

2 files changed, 84 insertions, 1 deletions

diff --git a/kernels/linux-libre-rt/CVE-2016-0728.patch b/kernels/linux-libre-rt/CVE-2016-0728.patch
new file mode 100644
index 000000000..e915d8219
--- /dev/null
+++ b/kernels/linux-libre-rt/CVE-2016-0728.patch
@@ -0,0 +1,78 @@
+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: [PATCH] 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 a3f85d2a..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;
+ 	}
diff --git a/kernels/linux-libre-rt/PKGBUILD b/kernels/linux-libre-rt/PKGBUILD
index c792ea821..96e723c66 100644
--- a/kernels/linux-libre-rt/PKGBUILD
+++ b/kernels/linux-libre-rt/PKGBUILD
@@ -21,7 +21,7 @@ _replacesoldmodules=() # '%' gets replaced with _kernelname
 _srcname=linux-${_pkgbasever%-*}
 _archpkgver=${_pkgver%-*}_${_rtpatchver}
 pkgver=${_pkgver//-/_}.${_rtpatchver}
-pkgrel=1
+pkgrel=2
 rcnrel=armv7-x6
 arch=('i686' 'x86_64' 'armv7h')
 url="https://rt.wiki.kernel.org/"
@@ -48,6 +48,7 @@ source=("http://linux-libre.fsfla.org/pub/linux-libre/releases/${_pkgbasever}/li
         # standard config files for mkinitcpio ramdisk
         'linux.preset'
         'change-default-console-loglevel.patch'
+        'CVE-2016-0728.patch'
         '0001-drm-radeon-Make-the-driver-load-without-the-firmwares.patch'
         '0002-usb-serial-gadget-no-TTY-hangup-on-USB-disconnect-WI.patch'
         # armv7h patches
@@ -78,6 +79,7 @@ sha256sums=('48b2e5ea077d0a0bdcb205e67178e8eb5b2867db3b2364b701dbc801d9755324'
             'ded625b4711e1390c36e581965cf4149cc6971657040c048a9f83ca9c9a0d11c'
             'f0d90e756f14533ee67afda280500511a62465b4f76adcc5effa95a40045179c'
             '1256b241cd477b265a3c2d64bdc19ffe3c9bbcee82ea3994c590c2c76e767d99'
+            '03bed5b1c6ef34a917e218a46d38cd1347c5ab5693131996113c6cad275dc4e9'
             '61370b766e0c60b407c29d2c44b3f55fc352e9049c448bc8fcddb0efc53e42fc'
             '3d3266bd082321dccf429cc2200d1a4d870d2031546f9f591b6dfbb698294808'
             'b485e9da38a70cb2a878714384ce4ddb36b0c3524b90d80cbff8a9a18c519e0b'
@@ -143,6 +145,9 @@ prepare() {
   # add latest fixes from stable queue, if needed
   # http://git.kernel.org/?p=linux/kernel/git/stable/stable-queue.git
 
+  # fixes #47820 CVE-2016-0728.patch
+  patch -Np1 -i "${srcdir}/CVE-2016-0728.patch"
+
   # set DEFAULT_CONSOLE_LOGLEVEL to 4 (same value as the 'quiet' kernel param)
   # remove this when a Kconfig knob is made available by upstream
   # (relevant patch sent upstream: https://lkml.org/lkml/2011/7/26/227)