Ethernet: Add a bounds check

Avoid to have p (current pointer on packet data) > ndo->ndo_snapend
in isoclns_print() in some cases.

Moreover:
Add a "FIXME" comment.

(cherry picked from commit 7b7b84716e604abd8bd92cee75e6385cab6ce3dc)

diff --git a/print-ether.c b/print-ether.c
index 2596cd6d7bad3dad47ba0f148ef9e6b93b269af3..da95862b3c0b5150a4b324f0439caf4eb828f395 100644 (file)
--- a/print-ether.c
+++ b/print-ether.c
@@ -564,6 +564,9 @@ ethertype_print(netdissect_options *ndo,
                        nd_print_trunc(ndo);
                        return (1);
                }
                        nd_print_trunc(ndo);
                        return (1);
                }

+               /* At least one byte is required */
+               /* FIXME: Reference for this byte? */
+               ND_TCHECK_LEN(p, 1);

                isoclns_print(ndo, p + 1, length - 1);
                return(1);
 
                isoclns_print(ndo, p + 1, length - 1);
                return(1);