[DRE-maint] Bug#717176: ruby-passenger: CVE-2013-4136: insecure tmp files usage

Felix Geyer fgeyer at debian.org
Sat Jul 20 17:32:42 UTC 2013


I've prepared a debdiff that cherry-picks another upstream
commit to properly fix CVE-2013-2119 and backports the two
commits necessary to fix CVE-2013-4136.

Cheers,
Felix
-------------- next part --------------
diff -Nru ruby-passenger-3.0.13debian/debian/changelog ruby-passenger-3.0.13debian/debian/changelog
--- ruby-passenger-3.0.13debian/debian/changelog	2013-05-30 12:41:00.000000000 +0200
+++ ruby-passenger-3.0.13debian/debian/changelog	2013-07-20 19:22:25.000000000 +0200
@@ -1,3 +1,12 @@
+ruby-passenger (3.0.13debian-1.2) unstable; urgency=high
+
+  * Non-maintainer upload.
+  * Cherry-pick another commit to properly fix CVE-2013-2119.
+  * Fix CVE-2013-4136: insecure tmp files usage. (Closes: #717176)
+    - Add CVE-2013-4136.patch, backported from upstream.
+
+ -- Felix Geyer <fgeyer at debian.org>  Sat, 20 Jul 2013 10:56:34 +0200
+
 ruby-passenger (3.0.13debian-1.1) unstable; urgency=low
 
   * Non-maintainer upload.
diff -Nru ruby-passenger-3.0.13debian/debian/patches/CVE-2013-2119.patch ruby-passenger-3.0.13debian/debian/patches/CVE-2013-2119.patch
--- ruby-passenger-3.0.13debian/debian/patches/CVE-2013-2119.patch	2013-05-30 09:31:09.000000000 +0200
+++ ruby-passenger-3.0.13debian/debian/patches/CVE-2013-2119.patch	2013-07-20 13:37:26.000000000 +0200
@@ -1,18 +1,8 @@
-From 0eaebb00f6b7327374069a7998064c68cc54e9f1 Mon Sep 17 00:00:00 2001
-From: "Hongli Lai (Phusion)" <hongli at phusion.nl>
-Date: Tue, 28 May 2013 22:30:53 +0200
-Subject: [PATCH] Ensure that temporary files and directories didn't already
- exist.
+Description: Fix for CVE-2013-2119: insecure tmp files usage
+Origin: upstream, https://github.com/phusion/passenger/commit/0eaebb00f6b7327374069a7998064c68cc54e9f1
+ and https://github.com/phusion/passenger/commit/56d9d39fb522e0967acbde0bcec1afc37313ceb4
+Bug-Debian: http://bugs.debian.org/710351
 
----
- bin/passenger-install-nginx-module                 |  7 ++---
- lib/phusion_passenger/dependencies.rb              | 32 ++++++++--------------
- lib/phusion_passenger/standalone/command.rb        |  9 +++---
- .../standalone/runtime_installer.rb                |  7 ++---
- 4 files changed, 23 insertions(+), 32 deletions(-)
-
-diff --git a/bin/passenger-install-nginx-module b/bin/passenger-install-nginx-module
-index 629240c..450252c 100755
 --- a/bin/passenger-install-nginx-module
 +++ b/bin/passenger-install-nginx-module
 @@ -27,6 +27,7 @@ $LOAD_PATH.unshift("#{passenger_root}/lib")
@@ -40,8 +30,6 @@
  	end
  
  private
-diff --git a/lib/phusion_passenger/dependencies.rb b/lib/phusion_passenger/dependencies.rb
-index e37a212..685b37d 100644
 --- a/lib/phusion_passenger/dependencies.rb
 +++ b/lib/phusion_passenger/dependencies.rb
 @@ -22,6 +22,7 @@
@@ -136,8 +124,6 @@
  			end
  		end
  		if RUBY_PLATFORM =~ /linux/
-diff --git a/lib/phusion_passenger/standalone/command.rb b/lib/phusion_passenger/standalone/command.rb
-index 8810427..b84909f 100644
 --- a/lib/phusion_passenger/standalone/command.rb
 +++ b/lib/phusion_passenger/standalone/command.rb
 @@ -172,8 +172,11 @@ def determine_various_resource_locations(create_subdirs = true)
@@ -163,8 +149,6 @@
  		if @options[:socket_file]
  			ping_spec = [:unix, @options[:socket_file]]
  		else
-diff --git a/lib/phusion_passenger/standalone/runtime_installer.rb b/lib/phusion_passenger/standalone/runtime_installer.rb
-index 730f776..31b6fd8 100644
 --- a/lib/phusion_passenger/standalone/runtime_installer.rb
 +++ b/lib/phusion_passenger/standalone/runtime_installer.rb
 @@ -23,6 +23,7 @@
@@ -194,6 +178,109 @@
  		@plugin.call_hook(:runtime_installer_cleanup) if @plugin
  	end
  
--- 
-1.8.1.6
-
+--- a/lib/phusion_passenger/platform_info.rb
++++ b/lib/phusion_passenger/platform_info.rb
+@@ -21,6 +21,8 @@
+ #  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ #  THE SOFTWARE.
+ 
++require 'tmpdir'
++
+ module PhusionPassenger
+ 
+ # This module autodetects various platform-specific information, and
+@@ -263,15 +265,12 @@ def self.try_compile(language, source, flags = nil)
+ 		else
+ 			raise ArgumentError,"Unsupported language '#{language}'"
+ 		end
+-		filename = File.join("#{tmpexedir}/passenger-compile-check-#{Process.pid}.c")
+-		File.open(filename, "w") do |f|
+-			f.puts(source)
+-		end
+-		begin
++		Dir.mktmpdir("passenger.", tmpexedir) do |dir|
++			filename = File.join(dir, "check.c")
++			File.open(filename, "w") do |f|
++				f.puts(source)
++			end
+ 			return system("(#{compiler} #{flags} -c '#{filename}' -o '#{filename}.o') >/dev/null 2>/dev/null")
+-		ensure
+-			File.unlink(filename) rescue nil
+-			File.unlink("#{filename}.o") rescue nil
+ 		end
+ 	end
+ 	private_class_method :try_compile
+@@ -284,15 +283,12 @@ def self.try_link(language, source, flags = nil)
+ 		else
+ 			raise ArgumentError,"Unsupported language '#{language}'"
+ 		end
+-		filename = File.join("#{tmpexedir}/passenger-link-check-#{Process.pid}.c")
+-		File.open(filename, "w") do |f|
+-			f.puts(source)
+-		end
+-		begin
++		Dir.mktmpdir("passenger.", tmpexedir) do |dir|
++			filename = File.join(dir, "check.c")
++			File.open(filename, "w") do |f|
++				f.puts(source)
++			end
+ 			return system("(#{compiler} #{flags} '#{filename}' -o '#{filename}.out') >/dev/null 2>/dev/null")
+-		ensure
+-			File.unlink(filename) rescue nil
+-			File.unlink("#{filename}.out") rescue nil
+ 		end
+ 	end
+ 	private_class_method :try_link
+@@ -305,17 +301,16 @@ def self.try_compile_and_run(language, source, flags = nil)
+ 		else
+ 			raise ArgumentError,"Unsupported language '#{language}'"
+ 		end
+-		filename = File.join("#{tmpexedir}/passenger-compile-check-#{Process.pid}.c")
+-		File.open(filename, "w") do |f|
+-			f.puts(source)
+-		end
+-		begin
++		Dir.mktmpdir("passenger.", tmpexedir) do |dir|
++			filename = File.join(dir, "check.c")
++			File.open(filename, "w") do |f|
++				f.puts(source)
++			end
+ 			if system("(#{compiler} #{flags} '#{filename}' -o '#{filename}.out') >/dev/null 2>/dev/null")
+ 				if Process.respond_to?(:spawn)
+ 					pid = Process.spawn("#{filename}.out",
+ 						:out => ["/dev/null", "w"],
+ 						:err => ["/dev/null", "w"])
+-					
+ 				else
+ 					pid = fork do
+ 						STDOUT.reopen("/dev/null", "w")
+@@ -328,9 +323,6 @@ def self.try_compile_and_run(language, source, flags = nil)
+ 			else
+ 				return false
+ 			end
+-		ensure
+-			File.unlink(filename) rescue nil
+-			File.unlink("#{filename}.out") rescue nil
+ 		end
+ 	end
+ 	private_class_method :try_compile_and_run
+--- a/lib/phusion_passenger/platform_info/apache.rb
++++ b/lib/phusion_passenger/platform_info/apache.rb
+@@ -285,16 +285,7 @@ def self.apu_libs
+ 	# headers are placed into the same directory as the Apache headers,
+ 	# and so 'apr-config' and 'apu-config' won't be necessary in that case.
+ 	def self.apr_config_needed_for_building_apache_modules?
+-		filename = File.join("#{tmpexedir}/passenger-platform-check-#{Process.pid}.c")
+-		File.open(filename, "w") do |f|
+-			f.puts("#include <apr.h>")
+-		end
+-		begin
+-			return !system("(gcc #{apache2_module_cflags(false)} -c '#{filename}' -o '#{filename}.o') >/dev/null 2>/dev/null")
+-		ensure
+-			File.unlink(filename) rescue nil
+-			File.unlink("#{filename}.o") rescue nil
+-		end
++		return !try_compile(:c, "#include <apr.h>", apache2_module_cflags(false))
+ 	end
+ 	memoize :apr_config_needed_for_building_apache_modules?
+ 
diff -Nru ruby-passenger-3.0.13debian/debian/patches/CVE-2013-4136.patch ruby-passenger-3.0.13debian/debian/patches/CVE-2013-4136.patch
--- ruby-passenger-3.0.13debian/debian/patches/CVE-2013-4136.patch	1970-01-01 01:00:00.000000000 +0100
+++ ruby-passenger-3.0.13debian/debian/patches/CVE-2013-4136.patch	2013-07-20 19:16:24.000000000 +0200
@@ -0,0 +1,152 @@
+Description: Fix for CVE-2013-4136: insecure tmp files usage
+Origin: backport, https://github.com/phusion/passenger/commit/5483b3292cc2af1c83033eaaadec20dba4dcfd9b
+ and https://github.com/phusion/passenger/commit/9dda49f4a3ebe9bafc48da1bd45799f30ce19566
+Bug: https://code.google.com/p/phusion-passenger/issues/detail?id=910
+Bug-Debian: http://bugs.debian.org/717176
+
+--- a/ext/common/LoggingAgent/Main.cpp
++++ b/ext/common/LoggingAgent/Main.cpp
+@@ -265,11 +265,6 @@
+ 		ev::sig sigtermWatcher(eventLoop);
+ 		ev::sig sigquitWatcher(eventLoop);
+ 		
+-		if (feedbackFdAvailable()) {
+-			feedbackFdWatcher.set<&feedbackFdBecameReadable>();
+-			feedbackFdWatcher.start(FEEDBACK_FD, ev::READ);
+-			writeArrayMessage(FEEDBACK_FD, "initialized", NULL);
+-		}
+ 		sigintWatcher.set<&caughtExitSignal>();
+ 		sigintWatcher.start(SIGINT);
+ 		sigtermWatcher.set<&caughtExitSignal>();
+@@ -281,6 +276,11 @@
+ 		/********** Initialized! Enter main loop... **********/
+ 		
+ 		P_DEBUG("Logging agent online, listening at " << socketAddress);
++		if (feedbackFdAvailable()) {
++			feedbackFdWatcher.set<&feedbackFdBecameReadable>();
++			feedbackFdWatcher.start(FEEDBACK_FD, ev::READ);
++			writeArrayMessage(FEEDBACK_FD, "initialized", NULL);
++		}
+ 		ev_loop(eventLoop, 0);
+ 		return exitCode;
+ 	} catch (const tracable_exception &e) {
+--- a/ext/common/ServerInstanceDir.h
++++ b/ext/common/ServerInstanceDir.h
+@@ -30,6 +30,7 @@
+ #include <oxt/backtrace.hpp>
+ 
+ #include <sys/types.h>
++#include <sys/stat.h>
+ #include <dirent.h>
+ #include <unistd.h>
+ #include <pwd.h>
+@@ -38,6 +39,7 @@
+ #include <cstring>
+ #include <string>
+ 
++#include <Logging.h>
+ #include "Exceptions.h"
+ #include "Utils.h"
+ #include "Utils/StrIntUtils.h"
+@@ -47,6 +49,15 @@
+ using namespace std;
+ using namespace boost;
+ 
++/* TODO: I think we should move away from generation dirs in the future.
++ * That way we can become immune to existing-directory-in-tmp denial of
++ * service attacks. To achieve the same functionality as we do now, each
++ * server instance directory is tagged with the control process's PID
++ * and a creation timestamp. passenger-status should treat the server instance
++ * directory with the most recent creation timestamp as the one to query.
++ * For now, the current code does not lead to an exploit.
++ */
++
+ class ServerInstanceDir: public noncopyable {
+ public:
+ 	// Don't forget to update lib/phusion_passenger/admin_tools/server_instance.rb too.
+@@ -217,7 +228,69 @@
+ 		 * rights though, because we want admin tools to be able to list the available
+ 		 * generations no matter what user they're running as.
+ 		 */
+-		makeDirTree(path, "u=rwxs,g=rx,o=rx");
++		if (owner) {
++			switch (getFileType(path)) {
++			case FT_NONEXISTANT:
++				createDirectory(path);
++				break;
++			case FT_DIRECTORY:
++				verifyDirectoryPermissions(path);
++				break;
++			default:
++				throw RuntimeException("'" + path + "' already exists, and is not a directory");
++			}
++		} else if (getFileType(path) != FT_DIRECTORY) {
++			throw RuntimeException("Server instance directory '" + path +
++				"' does not exist");
++		}
++	}
++
++	void createDirectory(const string &path) const {
++		// We do not use makeDirTree() here. If an attacker creates a directory
++		// just before we do, then we want to abort because we want the directory
++		// to have specific permissions.
++		if (mkdir(path.c_str(), parseModeString("u=rwx,g=rx,o=rx")) == -1) {
++			int e = errno;
++			throw FileSystemException("Cannot create server instance directory '" +
++				path + "'", e, path);
++		}
++		// verifyDirectoryPermissions() checks for the owner/group so we must make
++		// sure the server instance directory has that owner/group, even when the
++		// parent directory has setgid on.
++		if (chown(path.c_str(), geteuid(), getegid()) == -1) {
++			int e = errno;
++			throw FileSystemException("Cannot change the permissions of the server "
++				"instance directory '" + path + "'", e, path);
++		}
++	}
++
++	/**
++	 * When reusing an existing server instance directory, check permissions
++	 * so that an attacker cannot pre-create a directory with too liberal
++	 * permissions.
++	 */
++	void verifyDirectoryPermissions(const string &path) {
++		TRACE_POINT();
++		struct stat buf;
++
++		if (stat(path.c_str(), &buf) == -1) {
++			int e = errno;
++			throw FileSystemException("Cannot stat() " + path, e, path);
++		} else if (buf.st_mode != (S_IFDIR | parseModeString("u=rwx,g=rx,o=rx"))) {
++			throw RuntimeException("Tried to reuse existing server instance directory " +
++				path + ", but it has wrong permissions");
++		} else if (buf.st_uid != geteuid() || buf.st_gid != getegid()) {
++			/* The server instance directory is always created by the Watchdog. Its UID/GID never
++			 * changes because:
++			 * 1. Disabling user switching only lowers the privilege of the HelperAgent.
++			 * 2. For the UID/GID to change, the web server must be completely restarted
++			 *    (not just graceful reload) so that the control process can change its UID/GID.
++			 *    This causes the PID to change, so that an entirely new server instance
++			 *    directory is created.
++			 */
++			throw RuntimeException("Tried to reuse existing server instance directory " +
++				path + ", but it has wrong owner and group");
++		}
+ 	}
+ 	
+ 	bool isDirectory(const string &dir, struct dirent *entry) const {
+--- a/test/cxx/ServerInstanceDirTest.cpp
++++ b/test/cxx/ServerInstanceDirTest.cpp
+@@ -73,9 +73,11 @@
+ 	}
+ 	
+ 	TEST_METHOD(5) {
+-		// The destructor doesnn't remove the server instance directory if it
++		// The destructor doesn't remove the server instance directory if it
+ 		// wasn't created with the ownership flag or if it's been detached.
+ 		string path, path2;
++		makeDirTree(parentDir + "/passenger-test.1234");
++		makeDirTree(parentDir + "/passenger-test.5678");
+ 		{
+ 			ServerInstanceDir dir(1234, parentDir, false);
+ 			ServerInstanceDir dir2(5678, parentDir);
diff -Nru ruby-passenger-3.0.13debian/debian/patches/series ruby-passenger-3.0.13debian/debian/patches/series
--- ruby-passenger-3.0.13debian/debian/patches/series	2013-05-30 09:48:17.000000000 +0200
+++ ruby-passenger-3.0.13debian/debian/patches/series	2013-07-20 10:56:30.000000000 +0200
@@ -1,3 +1,4 @@
 fix_install_path.patch
 fix_ftbfs_glibc217.patch
 CVE-2013-2119.patch
+CVE-2013-4136.patch


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