From 9d8f374397db2ee32840d0f0e2bb2d7539758a0d Mon Sep 17 00:00:00 2001
From: "Todd C. Miller" <Todd.Miller@sudo.ws>
Date: Tue, 25 Jun 2019 09:45:10 -0600
Subject: [PATCH] Add ssizeof macro that returns ssize_t. We can use this
 instead of casting the result of size_t to int. Also change checks for
 snprintf() returning <=0 to <0.

---
 include/sudo_util.h                     | 3 +++
 lib/util/fatal.c                        | 2 +-
 lib/util/inet_ntop.c                    | 2 +-
 lib/util/regress/vsyslog/vsyslog_test.c | 6 +++---
 lib/util/sudo_debug.c                   | 4 ++--
 plugins/sudoers/find_path.c             | 4 ++--
 plugins/sudoers/group_plugin.c          | 2 +-
 plugins/sudoers/iolog.c                 | 4 ++--
 plugins/sudoers/ldap.c                  | 2 +-
 plugins/sudoers/ldap_conf.c             | 2 +-
 plugins/sudoers/logging.c               | 2 +-
 plugins/sudoers/sudoers.c               | 2 +-
 plugins/sudoers/sudoreplay.c            | 8 ++++----
 plugins/sudoers/timestamp.c             | 4 ++--
 src/load_plugins.c                      | 2 +-
 src/net_ifs.c                           | 6 +++---
 src/sudo.c                              | 4 ++--
 17 files changed, 31 insertions(+), 28 deletions(-)

diff --git a/include/sudo_util.h b/include/sudo_util.h
index 395dab616..a3904c178 100644
--- a/include/sudo_util.h
+++ b/include/sudo_util.h
@@ -144,6 +144,9 @@
 # define mtim_get(_x, _y)	do { (_y).tv_sec = (_x)->st_mtime; (_y).tv_nsec = 0; } while (0)
 #endif /* HAVE_ST_MTIM */
 
+/* sizeof() that returns a signed value */
+#define ssizeof(_x)	((ssize_t)sizeof(_x))
+
 /* Bit map macros. */
 #define sudo_setbit(_a, _i)	((_a)[(_i) / NBBY] |= 1 << ((_i) % NBBY))
 #define sudo_clrbit(_a, _i)	((_a)[(_i) / NBBY] &= ~(1<<((_i) % NBBY)))
diff --git a/lib/util/fatal.c b/lib/util/fatal.c
index 8dd690f2f..a377c3508 100644
--- a/lib/util/fatal.c
+++ b/lib/util/fatal.c
@@ -208,7 +208,7 @@ warning(const char *errstr, const char *fmt, va_list ap)
 		va_copy(ap2, ap);
 		buflen = vsnprintf(static_buf, sizeof(static_buf), fmt, ap2);
 		va_end(ap2);
-		if (buflen >= (int)sizeof(static_buf)) {
+		if (buflen >= ssizeof(static_buf)) {
 		    buf = malloc(++buflen);
 		    if (buf != NULL)
 			(void)vsnprintf(buf, buflen, fmt, ap);
diff --git a/lib/util/inet_ntop.c b/lib/util/inet_ntop.c
index 2f719e70f..108b887b0 100644
--- a/lib/util/inet_ntop.c
+++ b/lib/util/inet_ntop.c
@@ -79,7 +79,7 @@ inet_ntop4(const unsigned char *src, char *dst, socklen_t size)
 	int len;
 
 	len = snprintf(dst, size, fmt, src[0], src[1], src[2], src[3]);
-	if (len <= 0 || len >= size) {
+	if (len < 0 || len >= size) {
 		errno = ENOSPC;
 		return (NULL);
 	}
diff --git a/lib/util/regress/vsyslog/vsyslog_test.c b/lib/util/regress/vsyslog/vsyslog_test.c
index 0ad07378b..6c304181a 100644
--- a/lib/util/regress/vsyslog/vsyslog_test.c
+++ b/lib/util/regress/vsyslog/vsyslog_test.c
@@ -99,7 +99,7 @@ main(int argc, char *argv[])
     /* Test small buffer w/ errno. */
     len = snprintf(buf1, sizeof(buf1),
 	 "unable to open %s: %s", "/var/log/sudo-io/seq", strerror(ENOENT));
-    if (len < 0 || len >= (int)sizeof(buf1))
+    if (len < 0 || len >= ssizeof(buf1))
 	sudo_warnx_nodebug("buf1 trucated at %s:%d", __FILE__, __LINE__);
     expected_result = buf1;
     errno = ENOENT;
@@ -115,7 +115,7 @@ main(int argc, char *argv[])
     memset(buf1, 'b', 8184);
     buf1[8184] = '\0';
     len = snprintf(buf2, sizeof(buf2), "%s: %s", buf1, strerror(EINVAL));
-    if (len < 0 || len >= (int)sizeof(buf2))
+    if (len < 0 || len >= ssizeof(buf2))
 	sudo_warnx_nodebug("buf2 trucated at %s:%d", __FILE__, __LINE__);
     expected_result = buf2;
     errno = EINVAL;
@@ -125,7 +125,7 @@ main(int argc, char *argv[])
     memset(buf1, 'b', 8184);
     buf1[8184] = '\0';
     len = snprintf(buf2, sizeof(buf2), "%.*s", 2047, buf1);
-    if (len < 0 || len >= (int)sizeof(buf2))
+    if (len < 0 || len >= ssizeof(buf2))
 	sudo_warnx_nodebug("buf2 trucated at %s:%d", __FILE__, __LINE__);
     expected_result = buf2;
     test_vsyslog(0, buf1);
diff --git a/lib/util/sudo_debug.c b/lib/util/sudo_debug.c
index 4c8414821..d09c2b8c6 100644
--- a/lib/util/sudo_debug.c
+++ b/lib/util/sudo_debug.c
@@ -653,7 +653,7 @@ sudo_debug_vprintf2_v1(const char *func, const char *file, int lineno, int level
 	    va_copy(ap2, ap);
 	    buflen = fmt ? vsnprintf(static_buf, sizeof(static_buf), fmt, ap2) : 0;
 	    va_end(ap2);
-	    if (buflen >= (int)sizeof(static_buf)) {
+	    if (buflen >= ssizeof(static_buf)) {
 		va_list ap3;
 
 		/* Not enough room in static buf, allocate dynamically. */
@@ -763,7 +763,7 @@ sudo_debug_execve2_v1(int level, const char *path, char *const argv[], char *con
 		buflen += strlen(*av) + 1;
 	    buflen--;
 	}
-	if (buflen >= (int)sizeof(static_buf)) {
+	if (buflen >= ssizeof(static_buf)) {
 	    buf = malloc(buflen + 1);
 	    if (buf == NULL)
 		goto out;
diff --git a/plugins/sudoers/find_path.c b/plugins/sudoers/find_path.c
index 8e2f1fb88..0656339f8 100644
--- a/plugins/sudoers/find_path.c
+++ b/plugins/sudoers/find_path.c
@@ -142,7 +142,7 @@ find_path(const char *infile, char **outfile, struct stat *sbp,
 	 */
 	len = snprintf(command, sizeof(command), "%.*s/%s",
 	    (int)(ep - cp), cp, infile);
-	if (len <= 0 || len >= (int)sizeof(command)) {
+	if (len < 0 || len >= ssizeof(command)) {
 	    errno = ENAMETOOLONG;
 	    debug_return_int(NOT_FOUND_ERROR);
 	}
@@ -156,7 +156,7 @@ find_path(const char *infile, char **outfile, struct stat *sbp,
      */
     if (!found && checkdot) {
 	len = snprintf(command, sizeof(command), "./%s", infile);
-	if (len <= 0 || len >= (int)sizeof(command)) {
+	if (len < 0 || len >= ssizeof(command)) {
 	    errno = ENAMETOOLONG;
 	    debug_return_int(NOT_FOUND_ERROR);
 	}
diff --git a/plugins/sudoers/group_plugin.c b/plugins/sudoers/group_plugin.c
index 1a7e00ba4..7364881ba 100644
--- a/plugins/sudoers/group_plugin.c
+++ b/plugins/sudoers/group_plugin.c
@@ -74,7 +74,7 @@ group_plugin_load(char *plugin_info)
 	len = snprintf(path, sizeof(path), "%s%s",
 	    (*plugin_info != '/') ? path_plugin_dir : "", plugin_info);
     }
-    if (len <= 0 || len >= (int)sizeof(path)) {
+    if (len < 0 || len >= ssizeof(path)) {
 	errno = ENAMETOOLONG;
 	sudo_warn("%s%s",
 	    (*plugin_info != '/') ? path_plugin_dir : "", plugin_info);
diff --git a/plugins/sudoers/iolog.c b/plugins/sudoers/iolog.c
index 1fa4239f3..2fd52dee8 100644
--- a/plugins/sudoers/iolog.c
+++ b/plugins/sudoers/iolog.c
@@ -403,7 +403,7 @@ io_nextid(char *iolog_dir, char *iolog_dir_fallback, char sessid[7])
      * Open sequence file
      */
     len = snprintf(pathbuf, sizeof(pathbuf), "%s/seq", iolog_dir);
-    if (len <= 0 || len >= (int)sizeof(pathbuf)) {
+    if (len < 0 || len >= ssizeof(pathbuf)) {
 	errno = ENAMETOOLONG;
 	log_warning(SLOG_SEND_MAIL, "%s/seq", pathbuf);
 	goto done;
@@ -431,7 +431,7 @@ io_nextid(char *iolog_dir, char *iolog_dir_fallback, char sessid[7])
 
 	len = snprintf(fallback, sizeof(fallback), "%s/seq",
 	    iolog_dir_fallback);
-	if (len > 0 && len < (int)sizeof(fallback)) {
+	if (len > 0 && len < ssizeof(fallback)) {
 	    int fd2 = io_open(fallback, O_RDWR|O_CREAT, iolog_filemode);
 	    if (fd2 != -1) {
 		if (fchown(fd2, iolog_uid, iolog_gid) != 0) {
diff --git a/plugins/sudoers/ldap.c b/plugins/sudoers/ldap.c
index 417b87058..3bbd25237 100644
--- a/plugins/sudoers/ldap.c
+++ b/plugins/sudoers/ldap.c
@@ -492,7 +492,7 @@ sudo_ldap_timefilter(char *buffer, size_t buffersize)
     /* Build filter. */
     len = snprintf(buffer, buffersize, "(&(|(!(sudoNotAfter=*))(sudoNotAfter>=%s))(|(!(sudoNotBefore=*))(sudoNotBefore<=%s)))",
 	timebuffer, timebuffer);
-    if (len <= 0 || (size_t)len >= buffersize) {
+    if (len < 0 || (size_t)len >= buffersize) {
 	sudo_warnx(U_("internal error, %s overflow"), __func__);
 	errno = EOVERFLOW;
 	len = -1;
diff --git a/plugins/sudoers/ldap_conf.c b/plugins/sudoers/ldap_conf.c
index 157aafc4d..b6da4af88 100644
--- a/plugins/sudoers/ldap_conf.c
+++ b/plugins/sudoers/ldap_conf.c
@@ -201,7 +201,7 @@ sudo_ldap_conf_add_ports(void)
 
     hostbuf[0] = '\0';
     len = snprintf(defport, sizeof(defport), ":%d", ldap_conf.port);
-    if (len <= 0 || len >= (int)sizeof(defport)) {
+    if (len < 0 || len >= ssizeof(defport)) {
 	sudo_warnx(U_("sudo_ldap_conf_add_ports: port too large"));
 	debug_return_bool(false);
     }
diff --git a/plugins/sudoers/logging.c b/plugins/sudoers/logging.c
index 6064105b2..dcb198e89 100644
--- a/plugins/sudoers/logging.c
+++ b/plugins/sudoers/logging.c
@@ -466,7 +466,7 @@ fmt_authfail_message(char **str, va_list ap)
 		break;
 	    case 'd':
 		len = snprintf(dst, dst_end - dst, "%u", tries);
-		if (len <= 0 || len >= (int)(dst_end - dst))
+		if (len < 0 || len >= (int)(dst_end - dst))
 		    goto done;
 		dst += len;
 		src += 2;
diff --git a/plugins/sudoers/sudoers.c b/plugins/sudoers/sudoers.c
index 5ec1bc3d3..519c38eda 100644
--- a/plugins/sudoers/sudoers.c
+++ b/plugins/sudoers/sudoers.c
@@ -1246,7 +1246,7 @@ create_admin_success_flag(void)
     /* Build path to flag file. */
     len = snprintf(flagfile, sizeof(flagfile), "%s/.sudo_as_admin_successful",
 	user_dir);
-    if (len <= 0 || len >= (int)sizeof(flagfile))
+    if (len < 0 || len >= ssizeof(flagfile))
 	debug_return_int(false);
 
     /* Create admin flag file if it doesn't already exist. */
diff --git a/plugins/sudoers/sudoreplay.c b/plugins/sudoers/sudoreplay.c
index 255531417..1dba39cff 100644
--- a/plugins/sudoers/sudoreplay.c
+++ b/plugins/sudoers/sudoreplay.c
@@ -317,13 +317,13 @@ main(int argc, char *argv[])
     if (VALID_ID(id)) {
 	plen = snprintf(path, sizeof(path), "%s/%.2s/%.2s/%.2s/timing",
 	    session_dir, id, &id[2], &id[4]);
-	if (plen <= 0 || plen >= (int)sizeof(path))
+	if (plen < 0 || plen >= ssizeof(path))
 	    sudo_fatalx(U_("%s/%.2s/%.2s/%.2s/timing: %s"), session_dir,
 		id, &id[2], &id[4], strerror(ENAMETOOLONG));
     } else {
 	plen = snprintf(path, sizeof(path), "%s/%s/timing",
 	    session_dir, id);
-	if (plen <= 0 || plen >= (int)sizeof(path))
+	if (plen < 0 || plen >= ssizeof(path))
 	    sudo_fatalx(U_("%s/%s/timing: %s"), session_dir,
 		id, strerror(ENAMETOOLONG));
     }
@@ -619,7 +619,7 @@ xterm_set_size(int rows, int cols)
 
     /* XXX - save cursor and position restore after resizing */
     len = snprintf(buf, sizeof(buf), setsize_fmt, rows, cols);
-    if (len <= 0 || len >= (int)sizeof(buf)) {
+    if (len < 0 || len >= ssizeof(buf)) {
 	/* not possible due to size of buf */
 	sudo_debug_printf(SUDO_DEBUG_ERROR|SUDO_DEBUG_LINENO,
 	    "%s: internal error, buffer too small?", __func__);
@@ -1473,7 +1473,7 @@ find_sessions(const char *dir, regex_t *re, const char *user, const char *tty)
 	for (i = 0; i < sessions_len; i++) {
 	    len = snprintf(&pathbuf[sdlen], sizeof(pathbuf) - sdlen,
 		"%s/log", sessions[i]);
-	    if (len <= 0 || (size_t)len >= sizeof(pathbuf) - sdlen) {
+	    if (len < 0 || (size_t)len >= sizeof(pathbuf) - sdlen) {
 		errno = ENAMETOOLONG;
 		sudo_fatal("%s/%s/log", dir, sessions[i]);
 	    }
diff --git a/plugins/sudoers/timestamp.c b/plugins/sudoers/timestamp.c
index 5fe1abf40..d315723af 100644
--- a/plugins/sudoers/timestamp.c
+++ b/plugins/sudoers/timestamp.c
@@ -1023,7 +1023,7 @@ already_lectured(int unused)
     if (ts_secure_dir(def_lecture_status_dir, false, true)) {
 	len = snprintf(status_file, sizeof(status_file), "%s/%s",
 	    def_lecture_status_dir, user_name);
-	if (len > 0 && len < (int)sizeof(status_file)) {
+	if (len > 0 && len < ssizeof(status_file)) {
 	    debug_return_bool(stat(status_file, &sb) == 0);
 	}
 	log_warningx(SLOG_SEND_MAIL, N_("lecture status path too long: %s/%s"),
@@ -1045,7 +1045,7 @@ set_lectured(void)
 
     len = snprintf(lecture_status, sizeof(lecture_status), "%s/%s",
 	def_lecture_status_dir, user_name);
-    if (len <= 0 || len >= (int)sizeof(lecture_status)) {
+    if (len < 0 || len >= ssizeof(lecture_status)) {
 	log_warningx(SLOG_SEND_MAIL, N_("lecture status path too long: %s/%s"),
 	    def_lecture_status_dir, user_name);
 	goto done;
diff --git a/src/load_plugins.c b/src/load_plugins.c
index 699f58a09..5851b8257 100644
--- a/src/load_plugins.c
+++ b/src/load_plugins.c
@@ -88,7 +88,7 @@ sudo_stat_plugin(struct plugin_info *info, char *fullpath,
 
 	len = snprintf(fullpath, pathsize, "%s%s", sudo_conf_plugin_dir_path(),
 	    info->path);
-	if (len <= 0 || (size_t)len >= pathsize) {
+	if (len < 0 || (size_t)len >= pathsize) {
 	    sudo_warnx(U_("error in %s, line %d while loading plugin \"%s\""),
 		_PATH_SUDO_CONF, info->lineno, info->symbol_name);
 	    sudo_warnx(U_("%s%s: %s"), sudo_conf_plugin_dir_path(), info->path,
diff --git a/src/net_ifs.c b/src/net_ifs.c
index d218a0524..e0de1e5ed 100644
--- a/src/net_ifs.c
+++ b/src/net_ifs.c
@@ -179,7 +179,7 @@ get_net_ifs(char **addrinfo)
 
 		len = snprintf(cp, ailen - (*addrinfo - cp),
 		    "%s%s/%s", cp == *addrinfo ? "" : " ", addrstr, maskstr);
-		if (len <= 0 || len >= ailen - (*addrinfo - cp)) {
+		if (len < 0 || len >= ailen - (*addrinfo - cp)) {
 		    sudo_warnx(U_("internal error, %s overflow"), __func__);
 		    goto done;
 		}
@@ -196,7 +196,7 @@ get_net_ifs(char **addrinfo)
 
 		len = snprintf(cp, ailen - (*addrinfo - cp),
 		    "%s%s/%s", cp == *addrinfo ? "" : " ", addrstr, maskstr);
-		if (len <= 0 || len >= ailen - (*addrinfo - cp)) {
+		if (len < 0 || len >= ailen - (*addrinfo - cp)) {
 		    sudo_warnx(U_("internal error, %s overflow"), __func__);
 		    goto done;
 		}
@@ -341,7 +341,7 @@ get_net_ifs(char **addrinfo)
 
 	len = snprintf(cp, ailen - (*addrinfo - cp),
 	    "%s%s/%s", cp == *addrinfo ? "" : " ", addrstr, maskstr);
-	if (len <= 0 || len >= ailen - (*addrinfo - cp)) {
+	if (len < 0 || len >= ailen - (*addrinfo - cp)) {
 	    sudo_warnx(U_("internal error, %s overflow"), __func__);
 	    goto done;
 	}
diff --git a/src/sudo.c b/src/sudo.c
index 211d2ebb2..011bfdfba 100644
--- a/src/sudo.c
+++ b/src/sudo.c
@@ -468,7 +468,7 @@ get_user_groups(struct user_details *ud)
     for (i = 0; i < ud->ngroups; i++) {
 	len = snprintf(cp, glsize - (cp - gid_list), "%s%u",
 	    i ? "," : "", (unsigned int)ud->groups[i]);
-	if (len <= 0 || (size_t)len >= glsize - (cp - gid_list))
+	if (len < 0 || (size_t)len >= glsize - (cp - gid_list))
 	    sudo_fatalx(U_("internal error, %s overflow"), __func__);
 	cp += len;
     }
@@ -864,7 +864,7 @@ sudo_check_suid(const char *sudo)
 
 		    int len = snprintf(pathbuf, sizeof(pathbuf), "%.*s/%s",
 			(int)(ep - cp), cp, sudo);
-		    if (len <= 0 || len >= (int)sizeof(pathbuf))
+		    if (len < 0 || len >= ssizeof(pathbuf))
 			continue;
 		    if (access(pathbuf, X_OK) == 0) {
 			sudo = pathbuf;
-- 
2.40.0