Fix gratuitous use of strdup and x_strdup

There is no need to copy strings passed as arguments to execve,
the only potentially noticeable effect of using strdup/x_strdup
would be a malformed argument list in case of memory allocation error.

Also, x_strdup, being a thin wrapper around strdup, is of no benefit
when its argument is known to be non-NULL, and should not be used in
such cases.

* modules/pam_cracklib/pam_cracklib.c (password_check): Use strdup
instead of x_strdup, the latter is of no benefit in this case.
* modules/pam_ftp/pam_ftp.c (lookup): Likewise.
* modules/pam_userdb/pam_userdb.c (user_lookup): Likewise.
* modules/pam_userdb/pam_userdb.h (x_strdup): Remove.
* modules/pam_mkhomedir/pam_mkhomedir.c (create_homedir): Do not use
x_strdup for strings passed as arguments to execve.
* modules/pam_unix/pam_unix_acct.c (_unix_run_verify_binary): Likewise.
* modules/pam_unix/pam_unix_passwd.c (_unix_run_update_binary): Likewise.
* modules/pam_unix/support.c (_unix_run_helper_binary): Likewise.
(_unix_verify_password): Use strdup instead of x_strdup, the latter
is of no benefit in this case.
* modules/pam_xauth/pam_xauth.c (run_coprocess): Do not use strdup for
strings passed as arguments to execv.

3 files changed, 21 insertions, 21 deletions

diff --git a/modules/pam_unix/pam_unix_acct.c b/modules/pam_unix/pam_unix_acct.c
index 8ec44492..dc505e73 100644
--- a/modules/pam_unix/pam_unix_acct.c
+++ b/modules/pam_unix/pam_unix_acct.c
@@ -101,7 +101,7 @@ int _unix_run_verify_binary(pam_handle_t *pamh, unsigned int ctrl,
     int i=0;
     struct rlimit rlim;
     static char *envp[] = { NULL };
-    char *args[] = { NULL, NULL, NULL, NULL };
+    const char *args[] = { NULL, NULL, NULL, NULL };
 
     /* reopen stdout as pipe */
     dup2(fds[1], STDOUT_FILENO);
@@ -130,11 +130,11 @@ int _unix_run_verify_binary(pam_handle_t *pamh, unsigned int ctrl,
     }
 
     /* exec binary helper */
-    args[0] = x_strdup(CHKPWD_HELPER);
-    args[1] = x_strdup(user);
-    args[2] = x_strdup("chkexpiry");
+    args[0] = CHKPWD_HELPER;
+    args[1] = user;
+    args[2] = "chkexpiry";
 
-    execve(CHKPWD_HELPER, args, envp);
+    execve(CHKPWD_HELPER, (char *const *) args, envp);
 
     pam_syslog(pamh, LOG_ERR, "helper binary execve failed: %m");
     /* should not get here: exit with error */
diff --git a/modules/pam_unix/pam_unix_passwd.c b/modules/pam_unix/pam_unix_passwd.c
index 0cfc0f4d..5f3a3db3 100644
--- a/modules/pam_unix/pam_unix_passwd.c
+++ b/modules/pam_unix/pam_unix_passwd.c
@@ -204,7 +204,7 @@ static int _unix_run_update_binary(pam_handle_t *pamh, unsigned int ctrl, const
         int i=0;
         struct rlimit rlim;
 	static char *envp[] = { NULL };
-	char *args[] = { NULL, NULL, NULL, NULL, NULL, NULL };
+	const char *args[] = { NULL, NULL, NULL, NULL, NULL, NULL };
         char buffer[16];
 
 	/* XXX - should really tidy up PAM here too */
@@ -222,18 +222,18 @@ static int _unix_run_update_binary(pam_handle_t *pamh, unsigned int ctrl, const
 	}
 
 	/* exec binary helper */
-	args[0] = x_strdup(UPDATE_HELPER);
-	args[1] = x_strdup(user);
-	args[2] = x_strdup("update");
+	args[0] = UPDATE_HELPER;
+	args[1] = user;
+	args[2] = "update";
 	if (on(UNIX_SHADOW, ctrl))
-		args[3] = x_strdup("1");
+		args[3] = "1";
 	else
-		args[3] = x_strdup("0");
+		args[3] = "0";
 
         snprintf(buffer, sizeof(buffer), "%d", remember);
-        args[4] = x_strdup(buffer);
+        args[4] = buffer;
 
-	execve(UPDATE_HELPER, args, envp);
+	execve(UPDATE_HELPER, (char *const *) args, envp);
 
 	/* should not get here: exit with error */
 	D(("helper binary is not available"));
diff --git a/modules/pam_unix/support.c b/modules/pam_unix/support.c
index 19d72e66..3a849c81 100644
--- a/modules/pam_unix/support.c
+++ b/modules/pam_unix/support.c
@@ -567,7 +567,7 @@ static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd,
         int i=0;
         struct rlimit rlim;
 	static char *envp[] = { NULL };
-	char *args[] = { NULL, NULL, NULL, NULL };
+	const char *args[] = { NULL, NULL, NULL, NULL };
 
 	/* XXX - should really tidy up PAM here too */
 
@@ -593,15 +593,15 @@ static int _unix_run_helper_binary(pam_handle_t *pamh, const char *passwd,
 	}
 
 	/* exec binary helper */
-	args[0] = strdup(CHKPWD_HELPER);
-	args[1] = x_strdup(user);
+	args[0] = CHKPWD_HELPER;
+	args[1] = user;
 	if (off(UNIX__NONULL, ctrl)) {	/* this means we've succeeded */
-	  args[2]=strdup("nullok");
+	  args[2]="nullok";
 	} else {
-	  args[2]=strdup("nonull");
+	  args[2]="nonull";
 	}
 
-	execve(CHKPWD_HELPER, args, envp);
+	execve(CHKPWD_HELPER, (char *const *) args, envp);
 
 	/* should not get here: exit with error */
 	D(("helper binary is not available"));
@@ -788,10 +788,10 @@ int _unix_verify_password(pam_handle_t * pamh, const char *name
 				login_name = "";
 			    }
 
-			        new->user = x_strdup(name ? name : "");
+			        new->user = strdup(name ? name : "");
 				new->uid = getuid();
 				new->euid = geteuid();
-				new->name = x_strdup(login_name);
+				new->name = strdup(login_name);
 
 				/* any previous failures for this user ? */
 				if (pam_get_data(pamh, data_name, &void_old)