Use a stack buffer for the debug message when possible, most are small.

diff --git a/lib/util/sudo_debug.c b/lib/util/sudo_debug.c
index b60980247d643a611d9a8d2194277f7fdd533250..6ea5994ec124fb6ec62a4954a5009db33e3d16c3 100644 (file)
--- a/lib/util/sudo_debug.c
+++ b/lib/util/sudo_debug.c
@@ -430,7 +430,7 @@ sudo_debug_vprintf2(const char *func, const char *file, int lineno, int level,
     const char *fmt, va_list ap)
 {
     int buflen, pri, subsys, saved_errno = errno;
-    char *buf = NULL;
+    char static_buf[1024], *buf = static_buf;
 
     if (!sudo_debug_mode)
        return;
@@ -441,14 +441,19 @@ sudo_debug_vprintf2(const char *func, const char *file, int lineno, int level,
 
     /* Make sure we want debug info at this level. */
     if (subsys < num_subsystems && sudo_debug_settings[subsys] >= pri) {
-       buflen = fmt ? vasprintf(&buf, fmt, ap) : 0;
+       buflen = fmt ? vsnprintf(static_buf, sizeof(static_buf), fmt, ap) : 0;
+       if (buflen >= (int)sizeof(static_buf)) {
+           /* Not enough room in static buf, allocate dynamically. */
+           buflen = vasprintf(&buf, fmt, ap);
+       }
        if (buflen != -1) {
            int errcode = ISSET(level, SUDO_DEBUG_ERRNO) ? saved_errno : 0;
            if (ISSET(level, SUDO_DEBUG_LINENO))
                sudo_debug_write2(func, file, lineno, buf, buflen, errcode);
            else
                sudo_debug_write2(NULL, NULL, 0, buf, buflen, errcode);
-           free(buf);
+           if (buf != static_buf)
+               free(buf);
        }
     }