Security fix (CVE-2013-3215). Fixes #3028

2 files changed, 87 insertions, 3 deletions

diff --git a/main/libcap-ng/APKBUILD b/main/libcap-ng/APKBUILD
index b511ad5d99..dfce0f6c26 100644
--- a/main/libcap-ng/APKBUILD
+++ b/main/libcap-ng/APKBUILD
@@ -10,13 +10,19 @@ depends=
 makedepends="python"
 install=
 subpackages="$pkgname-dev $pkgname-doc $pkgname-utils"
-source="http://people.redhat.com/sgrubb/libcap-ng/libcap-ng-$pkgver.tar.gz"
+source="http://people.redhat.com/sgrubb/libcap-ng/libcap-ng-$pkgver.tar.gz
+	CVE-2014-3215.patch
+	"
 
 _builddir="$srcdir"/$pkgname-$pkgver
 
 prepare() {
 	cd "$_builddir"
-	# apply patches here
+	for i in $source; do
+		case $i in
+		*.patch) msg $i; patch -p1 -i "$srcdir"/$i || return 1;;
+		esac
+	done
 }
 
 build() {
@@ -40,4 +46,5 @@ utils() {
 	mv "$pkgdir"/usr/bin/* "$subpkgdir"/usr/bin/
 }
 	
-md5sums="85c14a2442a3721383a1e2284e254846  libcap-ng-0.7.tar.gz"
+md5sums="85c14a2442a3721383a1e2284e254846  libcap-ng-0.7.tar.gz
+ae4866fe611b3d7656233c03244871de  CVE-2014-3215.patch"
diff --git a/main/libcap-ng/CVE-2014-3215.patch b/main/libcap-ng/CVE-2014-3215.patch
new file mode 100644
index 0000000000..e1e8afe45d
--- /dev/null
+++ b/main/libcap-ng/CVE-2014-3215.patch
@@ -0,0 +1,77 @@
+Index: docs/capng_lock.3
+===================================================================
+--- a/docs/capng_lock.3	(revision 55)
++++ b/docs/capng_lock.3	(working copy)
+@@ -8,12 +8,13 @@
+ 
+ .SH "DESCRIPTION"
+ 
+-capng_lock will take steps to prevent children of the current process to regain full privileges if the uid is 0. This should be called while possessing the CAP_SETPCAP capability in the kernel. This function will do the following if permitted by the kernel: Set the NOROOT option on for PR_SET_SECUREBITS, set the NOROOT_LOCKED option to on for PR_SET_SECUREBITS, set the PR_NO_SETUID_FIXUP option on for PR_SET_SECUREBITS, and set the PR_NO_SETUID_FIXUP_LOCKED option on for PR_SET_SECUREBITS.
++capng_lock will take steps to prevent children of the current process from gaining privileges by executing setuid programs.  This should be called while possessing the CAP_SETPCAP capability in the kernel.
+ 
++This function will do the following if permitted by the kernel:  If the kernel supports PR_SET_NO_NEW_PRIVS, it will use it.  Otherwise it will set the NOROOT option on for PR_SET_SECUREBITS, set the NOROOT_LOCKED option to on for PR_SET_SECUREBITS, set the PR_NO_SETUID_FIXUP option on for PR_SET_SECUREBITS, and set the PR_NO_SETUID_FIXUP_LOCKED option on for PR_SET_SECUREBITS.  If both fail, it will return an error.
+ 
+ .SH "RETURN VALUE"
+ 
+-This returns 0 on success and a negative number on failure. -1 means a failure setting any of the PR_SET_SECUREBITS options.
++This returns 0 on success and a negative number on failure. -1 means a failure to use PR_SET_NO_NEW_PRIVS and a failure setting any of the PR_SET_SECUREBITS options.
+ 
+ .SH "SEE ALSO"
+ 
+Index: src/cap-ng.c
+===================================================================
+--- a/src/cap-ng.c	(revision 55)
++++ b/src/cap-ng.c	(working copy)
+@@ -49,6 +49,7 @@
+  * 2.6.24 kernel	XATTR_NAME_CAPS
+  * 2.6.25 kernel	PR_CAPBSET_DROP, CAPABILITY_VERSION_2
+  * 2.6.26 kernel	PR_SET_SECUREBITS, SECURE_*_LOCKED, VERSION_3
++ * 3.5    kernel	PR_SET_NO_NEW_PRIVS
+  */
+ 
+ /* External syscall prototypes */
+@@ -126,6 +127,14 @@
+ #define SECURE_NO_SETUID_FIXUP_LOCKED   3  /* make bit-2 immutable */
+ #endif
+ 
++/* prctl values that we use */
++#ifndef PR_SET_SECUREBITS
++#define PR_SET_SECUREBITS		28
++#endif
++#ifndef PR_SET_NO_NEW_PRIVS
++#define PR_SET_NO_NEW_PRIVS		38
++#endif
++
+ // States: new, allocated, initted, updated, applied
+ typedef enum { CAPNG_NEW, CAPNG_ERROR, CAPNG_ALLOCATED, CAPNG_INIT,
+ 	CAPNG_UPDATED, CAPNG_APPLIED } capng_states_t;
+@@ -703,15 +712,22 @@
+ 
+ int capng_lock(void)
+ {
+-#ifdef PR_SET_SECUREBITS
+-	int rc = prctl(PR_SET_SECUREBITS,
+-			1 << SECURE_NOROOT |
+-			1 << SECURE_NOROOT_LOCKED |
+-			1 << SECURE_NO_SETUID_FIXUP |
+-			1 << SECURE_NO_SETUID_FIXUP_LOCKED, 0, 0, 0);
++	int rc;
++
++	// On Linux 3.5 and up, we can directly prevent ourselves and
++	// our descendents from gaining privileges.
++	if (prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0) == 0)
++		return 0;
++
++	// This kernel is too old or otherwise doesn't support
++	// PR_SET_NO_NEW_PRIVS.  Fall back to using securebits.
++	rc = prctl(PR_SET_SECUREBITS,
++		   1 << SECURE_NOROOT |
++		   1 << SECURE_NOROOT_LOCKED |
++		   1 << SECURE_NO_SETUID_FIXUP |
++		   1 << SECURE_NO_SETUID_FIXUP_LOCKED, 0, 0, 0);
+ 	if (rc)
+ 		return -1;
+-#endif
+ 
+ 	return 0;
+ }