[arch-commits] Commit in ecryptfs-utils/trunk (CVE-2016-1572.patch PKGBUILD)

[Timothy Redaelli]

    Date: Friday, January 22, 2016 @ 12:41:47
  Author: tredaelli
Revision: 158553

upgpkg: ecryptfs-utils 108-2

Fix for CVE-2016-1572 (FS#47844)

Added:
  ecryptfs-utils/trunk/CVE-2016-1572.patch
Modified:
  ecryptfs-utils/trunk/PKGBUILD

---------------------+
 CVE-2016-1572.patch |  101 ++++++++++++++++++++++++++++++++++++++++++++++++++
 PKGBUILD            |   17 +++++---
 2 files changed, 113 insertions(+), 5 deletions(-)

Added: CVE-2016-1572.patch
===================================================================
--- CVE-2016-1572.patch	                        (rev 0)
+++ CVE-2016-1572.patch	2016-01-22 11:41:47 UTC (rev 158553)
@@ -0,0 +1,101 @@
+From 8fcdb9ef8406cd05c45acef6210a3bfa0831e857 Mon Sep 17 00:00:00 2001
+From: Tyler Hicks <tyhicks at canonical.com>
+Date: Thu, 7 Jan 2016 19:39:14 -0600
+Subject: [PATCH] mount.ecryptfs_private: Validate mount destination fs type
+
+Refuse to mount over non-standard filesystems. Mounting over
+certain types filesystems is a red flag that the user is doing
+something devious, such as mounting over the /proc/self symlink
+target with malicious content in order to confuse programs that may
+attempt to parse those files. (LP: #1530566)
+
+https://launchpad.net/bugs/1530566
+---
+ debian/changelog                   |  8 +++++
+ src/utils/mount.ecryptfs_private.c | 61 ++++++++++++++++++++++++++++++++++++++
+ 2 files changed, 69 insertions(+)
+
+--- a/src/utils/mount.ecryptfs_private.c
++++ b/src/utils/mount.ecryptfs_private.c
+@@ -30,6 +30,7 @@
+ #include <sys/param.h>
+ #include <sys/stat.h>
+ #include <sys/types.h>
++#include <sys/vfs.h>
+ #include <ctype.h>
+ #include <errno.h>
+ #include <keyutils.h>
+@@ -220,6 +221,62 @@ err:
+ 	return NULL;
+ }
+ 
++static int check_cwd_f_type()
++{
++	/**
++	 * This is *not* a list of compatible lower filesystems list for
++	 * eCryptfs. This is a list of filesystems that we reasonably expect to
++	 * see mount.ecryptfs_private users mounting on top of. In other words,
++	 * the filesystem type of the 'target' parameter of mount(2).
++	 *
++	 * This whitelist is to prevent malicious mount.ecryptfs_private users
++	 * from mounting over filesystem types such as PROC_SUPER_MAGIC to
++	 * deceive other programs with a crafted /proc/self/*. See
++	 * https://launchpad.net/bugs/1530566 for more details.
++	 */
++	__SWORD_TYPE f_type_whitelist[] = {
++		0x61756673 /* AUFS_SUPER_MAGIC */,
++		0x9123683E /* BTRFS_SUPER_MAGIC */,
++		0x00C36400 /* CEPH_SUPER_MAGIC */,
++		0xFF534D42 /* CIFS_MAGIC_NUMBER */,
++		0x0000F15F /* ECRYPTFS_SUPER_MAGIC */,
++		0x0000EF53 /* EXT[234]_SUPER_MAGIC */,
++		0xF2F52010 /* F2FS_SUPER_MAGIC */,
++		0x65735546 /* FUSE_SUPER_MAGIC */,
++		0x01161970 /* GFS2_MAGIC */,
++		0x3153464A /* JFS_SUPER_MAGIC */,
++		0x0000564C /* NCP_SUPER_MAGIC */,
++		0x00006969 /* NFS_SUPER_MAGIC */,
++		0x00003434 /* NILFS_SUPER_MAGIC */,
++		0x5346544E /* NTFS_SB_MAGIC */,
++		0x794C7630 /* OVERLAYFS_SUPER_MAGIC */,
++		0x52654973 /* REISERFS_SUPER_MAGIC */,
++		0x73717368 /* SQUASHFS_MAGIC */,
++		0x01021994 /* TMPFS_MAGIC */,
++		0x58465342 /* XFS_SB_MAGIC */,
++		0x2FC12FC1 /* ZFS_SUPER_MAGIC */,
++	};
++	struct statfs buf;
++	size_t i, whitelist_len;
++
++	if (statfs(".", &buf) != 0) {
++		fprintf(stderr, "Failed to check filesystem type: %m\n");
++		return 1;
++	}
++
++	whitelist_len = sizeof(f_type_whitelist) / sizeof(*f_type_whitelist);
++	for (i = 0; i < whitelist_len; i++) {
++		if (buf.f_type == f_type_whitelist[i]) {
++			return 0;
++		}
++	}
++
++	fprintf(stderr,
++		"Refusing to mount over an unapproved filesystem type: %#lx\n",
++		buf.f_type);
++	return 1;
++}
++
+ int check_ownership_mnt(uid_t uid, char **mnt) {
+ /* Check ownership of mount point, chdir into it, and
+  * canonicalize the path for use in mtab updating.
+@@ -629,6 +686,10 @@ int main(int argc, char *argv[]) {
+  		goto fail;
+  	}
+ 
++	if (check_cwd_f_type() != 0) {
++		goto fail;
++	}
++
+ 	if (mounting == 1) {
+ 		/* Increment mount counter, errors non-fatal */
+ 		if (increment(fh_counter) < 0) {

Modified: PKGBUILD
===================================================================
--- PKGBUILD	2016-01-22 10:50:21 UTC (rev 158552)
+++ PKGBUILD	2016-01-22 11:41:47 UTC (rev 158553)
@@ -5,7 +5,7 @@
 
 pkgname=ecryptfs-utils
 pkgver=108
-pkgrel=1
+pkgrel=2
 arch=('i686' 'x86_64')
 pkgdesc="Enterprise-class stacked cryptographic filesystem for Linux"
 url="https://launchpad.net/ecryptfs"
@@ -14,19 +14,26 @@
 depends=('nss' 'pam')
 optdepends=('python2: for python module')
 source=("http://launchpad.net/ecryptfs/trunk/${pkgver}/+download/${pkgname}_${pkgver}.orig.tar.gz"
-        "${pkgname}_${pkgver}.orig.tar.gz.sig::http://launchpad.net/ecryptfs/trunk/${pkgver}/+download/..-${pkgname}_${pkgver}.orig.tar.gz.asc")
+        "${pkgname}_${pkgver}.orig.tar.gz.sig::http://launchpad.net/ecryptfs/trunk/${pkgver}/+download/..-${pkgname}_${pkgver}.orig.tar.gz.asc"
+        CVE-2016-1572.patch)
 md5sums=('80f2a73e14030239fa01a2f1e5606a0e'
-         'SKIP')
+         'SKIP'
+         '3932ca86f3f6e3c770d61d32b45ed3c0')
 validpgpkeys=('E2D9E1C5F9F5D59291F4607D95E64373F1529469')
 
+prepare() {
+  cd "${pkgname}-${pkgver}"
+  patch -p1 -i "$srcdir"/CVE-2016-1572.patch
+}
+
 build() {
-  cd "$srcdir/${pkgname}-${pkgver}"
+  cd "${pkgname}-${pkgver}"
   ./configure --prefix=/usr --with-pamdir=/usr/lib/security PYTHON=python2
   make
 }
 
 package() {
-  cd "$srcdir/${pkgname}-${pkgver}"
+  cd "${pkgname}-${pkgver}"
   make DESTDIR="$pkgdir/" rootsbindir='/usr/bin' install
   chmod +s "$pkgdir/usr/bin/mount.ecryptfs_private"
 }