pam: upstream patch to fix CVE-2014-2583

2 files changed, 51 insertions, 0 deletions

diff --git a/pkgs/os-specific/linux/pam/CVE-2014-2583.patch b/pkgs/os-specific/linux/pam/CVE-2014-2583.patch
new file mode 100644
index 00000000000..25b1f7549fa
--- /dev/null
+++ b/pkgs/os-specific/linux/pam/CVE-2014-2583.patch
@@ -0,0 +1,49 @@
+From 9dcead87e6d7f66d34e7a56d11a30daca367dffb Mon Sep 17 00:00:00 2001
+From: "Dmitry V. Levin" <ldv@altlinux.org>
+Date: Wed, 26 Mar 2014 22:17:23 +0000
+Subject: pam_timestamp: fix potential directory traversal issue (ticket #27)
+
+pam_timestamp uses values of PAM_RUSER and PAM_TTY as components of
+the timestamp pathname it creates, so extra care should be taken to
+avoid potential directory traversal issues.
+
+* modules/pam_timestamp/pam_timestamp.c (check_tty): Treat
+"." and ".." tty values as invalid.
+(get_ruser): Treat "." and ".." ruser values, as well as any ruser
+value containing '/', as invalid.
+
+Fixes CVE-2014-2583.
+
+Reported-by: Sebastian Krahmer <krahmer@suse.de>
+
+diff --git a/modules/pam_timestamp/pam_timestamp.c b/modules/pam_timestamp/pam_timestamp.c
+index 5193733..b3f08b1 100644
+--- a/modules/pam_timestamp/pam_timestamp.c
++++ b/modules/pam_timestamp/pam_timestamp.c
+@@ -158,7 +158,7 @@ check_tty(const char *tty)
+ 		tty = strrchr(tty, '/') + 1;
+ 	}
+ 	/* Make sure the tty wasn't actually a directory (no basename). */
+-	if (strlen(tty) == 0) {
++	if (!strlen(tty) || !strcmp(tty, ".") || !strcmp(tty, "..")) {
+ 		return NULL;
+ 	}
+ 	return tty;
+@@ -243,6 +243,17 @@ get_ruser(pam_handle_t *pamh, char *ruserbuf, size_t ruserbuflen)
+ 		if (pwd != NULL) {
+ 			ruser = pwd->pw_name;
+ 		}
++	} else {
++		/*
++		 * This ruser is used by format_timestamp_name as a component
++		 * of constructed timestamp pathname, so ".", "..", and '/'
++		 * are disallowed to avoid potential path traversal issues.
++		 */
++		if (!strcmp(ruser, ".") ||
++		    !strcmp(ruser, "..") ||
++		    strchr(ruser, '/')) {
++			ruser = NULL;
++		}
+ 	}
+ 	if (ruser == NULL || strlen(ruser) >= ruserbuflen) {
+ 		*ruserbuf = '\0';
diff --git a/pkgs/os-specific/linux/pam/default.nix b/pkgs/os-specific/linux/pam/default.nix
index afc125556fe..43b8204f50c 100644
--- a/pkgs/os-specific/linux/pam/default.nix
+++ b/pkgs/os-specific/linux/pam/default.nix
@@ -8,6 +8,8 @@ stdenv.mkDerivation rec {
     sha256 = "0m8ygb40l1c13nsd4hkj1yh4p1ldawhhg8pyjqj9w5kd4cxg5cf4";
   };
 
+  patches = [ ./CVE-2014-2583.patch ];
+
   nativeBuildInputs = [ flex ];
 
   buildInputs = [ cracklib ];