2 files changed, 41 insertions, 4 deletions
diff --git a/ldso/include/unsecvars.h b/ldso/include/unsecvars.h
new file mode 100644
index 000000000..5380f7363
--- /dev/null
+++ b/ldso/include/unsecvars.h
@@ -0,0 +1,26 @@
+/* 
+ * Environment variable to be removed for SUID programs.  The names are all
+ * stuffed in a single string which means they have to be terminated with a
+ * '\0' explicitly.
+ */
+
+#define UNSECURE_ENVVARS		\
+	"LD_AOUT_PRELOAD\0"		\
+	"LD_AOUT_LIBRARY_PATH\0"	\
+	"LD_PRELOAD\0"			\
+ 	"LD_LIBRARY_PATH\0"		\
+	"LD_DEBUG\0"			\
+	"LD_DEBUG_OUTPUT\0"		\
+	"HOSTALIASES\0"			\
+	"LOCALDOMAIN\0"			\
+	"RES_OPTIONS\0"			\
+	"TMPDIR\0"
+
+/* 
+ * These environment variables are defined by glibc but ignored in
+ * uClibc, but may very well have an equivalent in uClibc.
+ *
+ * MALLOC_TRACE, RESOLV_HOST_CONF, TZDIR, GCONV_PATH, LD_USE_LOAD_BIAS,
+ * LD_PROFILE, LD_ORIGIN_PATH, LOCPATH, NLSPATH
+ */
+
diff --git a/ldso/ldso/ldso.c b/ldso/ldso/ldso.c
index 78ce5c95f..02dd786f2 100644
--- a/ldso/ldso/ldso.c
+++ b/ldso/ldso/ldso.c
@@ -30,6 +30,7 @@
  */
 
 #include "ldso.h"
+#include "unsecvars.h"
 
 #define ALLOW_ZERO_PLTGOT
 
@@ -338,11 +339,21 @@ void _dl_get_ready_to_run(struct elf_resolve *tpnt, unsigned long load_addr,
 		_dl_preload = _dl_getenv("LD_PRELOAD", envp);
 		_dl_library_path = _dl_getenv("LD_LIBRARY_PATH", envp);
 	} else {
+		static const char unsecure_envvars[] =
+#ifdef EXTRA_UNSECURE_ENVVARS
+			EXTRA_UNSECURE_ENVVARS
+#endif
+			UNSECURE_ENVVARS;
+		const char *nextp;
 		_dl_secure = 1;
-		_dl_preload = _dl_getenv("LD_PRELOAD", envp);
-		_dl_unsetenv("LD_AOUT_PRELOAD", envp);
-		_dl_unsetenv("LD_LIBRARY_PATH", envp);
-		_dl_unsetenv("LD_AOUT_LIBRARY_PATH", envp);
+
+		nextp = unsecure_envvars;
+		do {
+			_dl_unsetenv (nextp, envp);
+			/* We could use rawmemchr but this need not be fast.  */
+			nextp = (char *) _dl_strchr(nextp, '\0') + 1;
+		} while (*nextp != '\0');
+		_dl_preload = NULL;
 		_dl_library_path = NULL;
 	}