Merge ~sergiodj/ubuntu/+source/strongswan:bug1964977-ipsec-pki-segfault into ubuntu/+source/strongswan:ubuntu/devel

[Sergio Durigan Junior]

This MP fixes bug 1964977.

This is about a segmentation fault that is occurring when using the "ipsec pki" command. It's very easy to reproduce:

$ lxc launch ubuntu-daily:jammy ipsec-bug1964977
$ lxc shell ipsec-bug1964977
# apt update && apt full-upgrade -y
# apt install strongswan strongswan-pki
# ipsec pki --gen --size 4096 --outform pem

Upstream has a patch for it:

https://github.com/strongswan/strongswan/commit/3eecd40cec6415fc033f8d9141ab652047e71524

As explained in the commit message, the problem happens because of some bad interaction between atexit handlers for both strongswan and openssl. Strongswan uses these handlers to unload/destroy its plugins, and the problem is that it tried to access openssl objects during these operations. However, with openssl's atexit handlers in place, this will now generate a segmentation fault. There's also an openssl bug about this problem here:

https://github.com/openssl/openssl/issues/15915

You can find a PPA with the proposed changes here:

https://launchpad.net/~sergiodj/+archive/ubuntu/strongswan-bugfix/+packages

autopkgtest is still OK:

autopkgtest [14:54:23]: @@@@@@@@@@@@@@@@@@@@ summary
admin-strongswan-charon PASS
admin-strongswan-starter PASS
daemon PASS
plugins PASS

[Simon Déziel (sdeziel)]

LGTM and I confirmed your package to work, thanks!

review: Approve (drive-by ;))

[Sergio Durigan Junior (sergiodj)]

On Friday, March 18 2022, Simon Déziel wrote:

> LGTM and I confirmed your package to work, thanks!

Thank you, Simon!

Uploaded:

$ dput strongswan_5.9.5-2ubuntu2_source.changes
Trying to upload package to ubuntu
Checking signature on .changes
gpg: /home/sergio/work/strongswan/strongswan_5.9.5-2ubuntu2_source.changes: Valid signature from 106DA1C8C3CBBF14
Checking signature on .dsc
gpg: /home/sergio/work/strongswan/strongswan_5.9.5-2ubuntu2.dsc: Valid signature from 106DA1C8C3CBBF14
Uploading to ubuntu (via ftp to upload.ubuntu.com):
  Uploading strongswan_5.9.5-2ubuntu2.dsc: done.
  Uploading strongswan_5.9.5-2ubuntu2.debian.tar.xz: done.
  Uploading strongswan_5.9.5-2ubuntu2_source.buildinfo: done.
  Uploading strongswan_5.9.5-2ubuntu2_source.changes: done.
Successfully uploaded packages.

--
Sergio
GPG key ID: E92F D0B3 6B14 F1F4 D8E0 EB2F 106D A1C8 C3CB BF14

diff --git a/debian/changelog b/debian/changelog
index 8d263b9..7a68e26 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,11 @@
+strongswan (5.9.5-2ubuntu2) jammy; urgency=medium
+
+  * d/p/lp1964977-fix-ipsec-pki-segfault.patch: Fix "ipsec pki"
+    segmentation fault; don't access OpenSSL objects inside atexit()
+    handlers. (LP: #1964977)
+
+ -- Sergio Durigan Junior <[e-mail]>  Fri, 18 Mar 2022 14:24:34 -0400
+
 strongswan (5.9.5-2ubuntu1) jammy; urgency=medium
 
   * Merge with Debian unstable. Remaining changes:
diff --git a/debian/patches/lp1964977-fix-ipsec-pki-segfault.patch b/debian/patches/lp1964977-fix-ipsec-pki-segfault.patch
new file mode 100644
index 0000000..c40972f
--- /dev/null
+++ b/debian/patches/lp1964977-fix-ipsec-pki-segfault.patch
@@ -0,0 +1,89 @@
+From: Tobias Brunner <[e-mail]>
+Date: Wed, 23 Feb 2022 17:29:02 +0100
+Subject: openssl: Don't unload providers
+
+There is a conflict between atexit() handlers registered by OpenSSL and
+some executables (e.g. swanctl or pki) to deinitialize libstrongswan.
+Because plugins are usually loaded after atexit() has been called, the
+handler registered by OpenSSL will run before our handler.  So when the
+latter destroys the plugins it's a bad idea to try to access any OpenSSL
+objects as they might already be invalid.
+
+Fixes: f556fce16b60 ("openssl: Load "legacy" provider in OpenSSL 3 for algorithms like MD4, DES etc.")
+Closes strongswan/strongswan#921
+
+Origin: upstream, https://github.com/strongswan/strongswan/commit/3eecd40cec6415fc033f8d9141ab652047e71524
+Bug: https://github.com/strongswan/strongswan/issues/921
+Bug: https://github.com/openssl/openssl/issues/15915
+Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/strongswan/+bug/1964977
+Applied-Upstream: 6.0dr14
+---
+ src/libstrongswan/plugins/openssl/openssl_plugin.c | 27 +++-------------------
+ 1 file changed, 3 insertions(+), 24 deletions(-)
+
+diff --git a/src/libstrongswan/plugins/openssl/openssl_plugin.c b/src/libstrongswan/plugins/openssl/openssl_plugin.c
+index c93ea60..f1d0ad8 100644
+--- a/src/libstrongswan/plugins/openssl/openssl_plugin.c
++++ b/src/libstrongswan/plugins/openssl/openssl_plugin.c
+@@ -16,7 +16,6 @@
+ 
+ #include <library.h>
+ #include <utils/debug.h>
+-#include <collections/array.h>
+ #include <threading/thread.h>
+ #include <threading/mutex.h>
+ #include <threading/thread_value.h>
+@@ -74,13 +73,6 @@ struct private_openssl_plugin_t {
+ 	 * public functions
+ 	 */
+ 	openssl_plugin_t public;
+-
+-#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+-	/**
+-	 * Loaded providers
+-	 */
+-	array_t *providers;
+-#endif
+ };
+ 
+ /**
+@@ -887,15 +879,6 @@ METHOD(plugin_t, get_features, int,
+ METHOD(plugin_t, destroy, void,
+ 	private_openssl_plugin_t *this)
+ {
+-#if OPENSSL_VERSION_NUMBER >= 0x30000000L
+-	OSSL_PROVIDER *provider;
+-	while (array_remove(this->providers, ARRAY_TAIL, &provider))
+-	{
+-		OSSL_PROVIDER_unload(provider);
+-	}
+-	array_destroy(this->providers);
+-#endif /* OPENSSL_VERSION_NUMBER */
+-
+ /* OpenSSL 1.1.0 cleans up itself at exit and while OPENSSL_cleanup() exists we
+  * can't call it as we couldn't re-initialize the library (as required by the
+  * unit tests and the Android app) */
+@@ -1009,20 +992,16 @@ plugin_t *openssl_plugin_create()
+ 			DBG1(DBG_LIB, "unable to load OpenSSL FIPS provider");
+ 			return NULL;
+ 		}
+-		array_insert_create(&this->providers, ARRAY_TAIL, fips);
+ 		/* explicitly load the base provider containing encoding functions */
+-		array_insert_create(&this->providers, ARRAY_TAIL,
+-							OSSL_PROVIDER_load(NULL, "base"));
++		OSSL_PROVIDER_load(NULL, "base");
+ 	}
+ 	else if (lib->settings->get_bool(lib->settings, "%s.plugins.openssl.load_legacy",
+ 									 TRUE, lib->ns))
+ 	{
+ 		/* load the legacy provider for algorithms like MD4, DES, BF etc. */
+-		array_insert_create(&this->providers, ARRAY_TAIL,
+-							OSSL_PROVIDER_load(NULL, "legacy"));
++		OSSL_PROVIDER_load(NULL, "legacy");
+ 		/* explicitly load the default provider, as mentioned by crypto(7) */
+-		array_insert_create(&this->providers, ARRAY_TAIL,
+-							OSSL_PROVIDER_load(NULL, "default"));
++		OSSL_PROVIDER_load(NULL, "default");
+ 	}
+ 	ossl_provider_names_t data = {};
+ 	OSSL_PROVIDER_do_all(NULL, concat_ossl_providers, &data);
diff --git a/debian/patches/series b/debian/patches/series
index c72895f..31ba246 100644
--- a/debian/patches/series
+++ b/debian/patches/series
@@ -3,3 +3,4 @@
 03_systemd-service.patch
 04_disable-libtls-tests.patch
 dont-load-kernel-libipsec-plugin-by-default.patch
+lp1964977-fix-ipsec-pki-segfault.patch