netbiosns: fix bug #53747 (need to verify received packet length)

This commit is contained in:
goldsimon 2018-04-25 20:56:34 +02:00
parent 373bf8c36d
commit b2ef9d9046

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@ -343,6 +343,12 @@ netbiosns_recv(void *arg, struct udp_pcb *upcb, struct pbuf *p, const ip_addr_t
struct netbios_hdr *netbios_hdr = (struct netbios_hdr *)p->payload;
struct netbios_name_hdr *netbios_name_hdr = (struct netbios_name_hdr *)(netbios_hdr + 1);
/* is the packet long enough (we need the header in one piece) */
if (p->len < (sizeof(struct netbios_hdr) + sizeof(struct netbios_name_hdr))) {
/* packet too short */
pbuf_free(p);
return;
}
/* we only answer if we got a default interface */
if (netif_default != NULL) {
/* @todo: do we need to check answerRRs/authorityRRs/additionalRRs? */