nmeter: fix read past the end if a buffer. Closes 4594

diff --git a/procps/nmeter.c b/procps/nmeter.c
index 48a5b4e..cded67e 100644 (file)
--- a/procps/nmeter.c
+++ b/procps/nmeter.c
@@ -786,8 +786,10 @@ int nmeter_main(int argc, char **argv)
        if (argc != 2)
                bb_show_usage();
 
-       if (open_read_close("version", buf, sizeof(buf)) > 0)
-               is26 = (strstr(buf, " 2.4.")==NULL);
+       if (open_read_close("version", buf, sizeof(buf)-1) > 0) {
+               buf[sizeof(buf)-1] = '\0';
+               is26 = (strstr(buf, " 2.4.") == NULL);
+       }
 
        // Can use argv[1] directly, but this will mess up
        // parameters as seen by e.g. ps. Making a copy...