Adding upstream version 2.39.3.upstream/2.39.3

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 264 insertions, 0 deletions

diff --git a/lib/env.c b/lib/env.c
new file mode 100644
index 0000000..2b3395c
--- /dev/null
+++ b/lib/env.c
@@ -0,0 +1,264 @@
+/*
+ * environ[] array cleanup code and getenv() wrappers
+ *
+ * No copyright is claimed.  This code is in the public domain; do with
+ * it what you wish.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#ifdef HAVE_SYS_PRCTL_H
+#include <sys/prctl.h>
+#else
+#define PR_GET_DUMPABLE 3
+#endif
+#if (!defined(HAVE_PRCTL) && defined(linux))
+#include <sys/syscall.h>
+#endif
+#include <unistd.h>
+#include <sys/types.h>
+
+#include "env.h"
+#include "all-io.h"
+
+#ifndef HAVE_ENVIRON_DECL
+extern char **environ;
+#endif
+
+static char * const forbid[] = {
+        "BASH_ENV=",    /* GNU creeping featurism strikes again... */
+        "ENV=",
+        "HOME=",
+        "IFS=",
+        "KRB_CONF=",
+        "LD_",          /* anything with the LD_ prefix */
+        "LIBPATH=",
+        "MAIL=",
+        "NLSPATH=",
+        "PATH=",
+        "SHELL=",
+        "SHLIB_PATH=",
+        (char *) 0
+};
+
+/* these are allowed, but with no slashes inside
+   (to work around security problems in GNU gettext) */
+static char * const noslash[] = {
+        "LANG=",
+        "LANGUAGE=",
+        "LC_",          /* anything with the LC_ prefix */
+        (char *) 0
+};
+
+
+struct ul_env_list {
+	char *env;
+	struct ul_env_list *next;
+};
+
+/*
+ * Saves @name env.variable to @ls, returns pointer to the new head of the list.
+ */
+static struct ul_env_list *env_list_add(struct ul_env_list *ls0, const char *str)
+{
+	struct ul_env_list *ls;
+	char *p;
+	size_t sz = 0;
+
+	if (!str || !*str)
+		return ls0;
+
+	sz = strlen(str) + 1;
+	p = malloc(sizeof(struct ul_env_list) + sz);
+	if (!p)
+		return ls0;
+
+	ls = (struct ul_env_list *) p;
+	p += sizeof(struct ul_env_list);
+	memcpy(p, str, sz);
+	ls->env = p;
+
+	ls->next = ls0;
+	return ls;
+}
+
+/*
+ * Use env_from_fd() to read environment from @fd.
+ *
+ * @fd must be /proc/<pid>/environ file.
+*/
+struct ul_env_list *env_from_fd(int fd)
+{
+	char *buf = NULL, *p;
+	ssize_t rc = 0;
+	struct ul_env_list *ls = NULL;
+
+	if ((rc = read_all_alloc(fd, &buf)) < 1)
+		return NULL;
+	buf[rc] = '\0';
+	p = buf;
+
+	while (rc > 0) {
+		ls = env_list_add(ls, p);
+		p += strlen(p) + 1;
+		rc -= strlen(p) + 1;
+	}
+
+	free(buf);
+	return ls;
+}
+
+/*
+ * Use setenv() for all stuff in @ls.
+ *
+ * It would be possible to use putenv(), but we want to keep @ls free()-able.
+ */
+int env_list_setenv(struct ul_env_list *ls)
+{
+	int rc = 0;
+
+	while (ls && rc == 0) {
+		if (ls->env) {
+			char *val = strchr(ls->env, '=');
+			if (!val)
+				continue;
+			*val = '\0';
+			rc = setenv(ls->env, val + 1, 0);
+			*val = '=';
+		}
+		ls = ls->next;
+	}
+	return rc;
+}
+
+void env_list_free(struct ul_env_list *ls)
+{
+	while (ls) {
+		struct ul_env_list *x = ls;
+		ls = ls->next;
+		free(x);
+	}
+}
+
+/*
+ * Removes unwanted variables from environ[]. If @org is not NULL than stores
+ * unwnated variables to the list.
+ */
+void __sanitize_env(struct ul_env_list **org)
+{
+        char **envp = environ;
+        char * const *bad;
+        char **cur;
+        int last = 0;
+
+        for (cur = envp; *cur; cur++)
+                last++;
+
+        for (cur = envp; *cur; cur++) {
+                for (bad = forbid; *bad; bad++) {
+                        if (strncmp(*cur, *bad, strlen(*bad)) == 0) {
+				if (org)
+					*org = env_list_add(*org, *cur);
+                                last = remote_entry(envp, cur - envp, last);
+                                cur--;
+                                break;
+                        }
+                }
+        }
+
+        for (cur = envp; *cur; cur++) {
+                for (bad = noslash; *bad; bad++) {
+                        if (strncmp(*cur, *bad, strlen(*bad)) != 0)
+                                continue;
+                        if (!strchr(*cur, '/'))
+                                continue;  /* OK */
+			if (org)
+				*org = env_list_add(*org, *cur);
+                        last = remote_entry(envp, cur - envp, last);
+                        cur--;
+                        break;
+                }
+        }
+}
+
+void sanitize_env(void)
+{
+	__sanitize_env(NULL);
+}
+
+char *safe_getenv(const char *arg)
+{
+	if ((getuid() != geteuid()) || (getgid() != getegid()))
+		return NULL;
+#ifdef HAVE_PRCTL
+	if (prctl(PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+		return NULL;
+#else
+#if (defined(linux) && defined(SYS_prctl))
+	if (syscall(SYS_prctl, PR_GET_DUMPABLE, 0, 0, 0, 0) == 0)
+		return NULL;
+#endif
+#endif
+#ifdef HAVE_SECURE_GETENV
+return secure_getenv(arg);
+#elif HAVE___SECURE_GETENV
+	return __secure_getenv(arg);
+#else
+	return getenv(arg);
+#endif
+}
+
+#ifdef TEST_PROGRAM
+int main(void)
+{
+	char *const *bad;
+	char copy[32];
+	char *p;
+	int retval = EXIT_SUCCESS;
+	struct ul_env_list *removed = NULL;
+
+	for (bad = forbid; *bad; bad++) {
+		strcpy(copy, *bad);
+		p = strchr(copy, '=');
+		if (p)
+			*p = '\0';
+		setenv(copy, copy, 1);
+	}
+
+	/* removed */
+	__sanitize_env(&removed);
+
+	/* check removal */
+	for (bad = forbid; *bad; bad++) {
+		strcpy(copy, *bad);
+		p = strchr(copy, '=');
+		if (p)
+			*p = '\0';
+		p = getenv(copy);
+		if (p) {
+			warnx("%s was not removed", copy);
+			retval = EXIT_FAILURE;
+		}
+	}
+
+	/* restore removed */
+	env_list_setenv(removed);
+
+	/* check restore */
+	for (bad = forbid; *bad; bad++) {
+		strcpy(copy, *bad);
+		p = strchr(copy, '=');
+		if (p)
+			*p = '\0';
+		p = getenv(copy);
+		if (!p) {
+			warnx("%s was not restored", copy);
+			retval = EXIT_FAILURE;
+		}
+	}
+
+	env_list_free(removed);
+
+	return retval;
+}
+#endif