CVE-2017-13687/CHDLC: Improve bounds and length checks.

[tcpdump] / print-fr.c

diff --git a/print-fr.c b/print-fr.c
index f400ddcd4f59aee585351c5e3ec19b4976e18974..da7ee25f0ab42c3deac9efdec3cb8342d6f5ef7a 100644 (file)
--- a/print-fr.c
+++ b/print-fr.c
@@ -906,6 +906,7 @@ q933_print(netdissect_options *ndo,
        ND_PRINT((ndo, "%s, codeset %u", is_ansi ? "ANSI" : "CCITT", codeset));
 
        if (call_ref_length != 0) {
+               ND_TCHECK(p[0]);
                if (call_ref_length > 1 || p[0] != 0) {
                        /*
                         * Not a dummy call reference.