Merge pull request #9187 from mobash-rasool/pim-upst-2

pimd: Validate the fields before accessing it
This commit is contained in:
Igor Ryzhov 2021-07-27 17:24:32 +03:00 committed by GitHub
commit 42ac787226
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GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 23 additions and 22 deletions

View File

@ -473,15 +473,33 @@ static int igmp_v1_recv_report(struct igmp_sock *igmp, struct in_addr from,
return 0;
}
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, int igmp_msg_len,
int msg_type)
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, size_t *hlen)
{
char *igmp_msg;
int igmp_msg_len;
int msg_type;
size_t ip_hlen; /* ip header length in bytes */
if (len < sizeof(*ip_hdr)) {
zlog_warn("IGMP packet size=%zu shorter than minimum=%zu", len,
sizeof(*ip_hdr));
return false;
}
ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */
*hlen = ip_hlen;
if (ip_hlen > len) {
zlog_warn(
"IGMP packet header claims size %zu, but we only have %zu bytes",
ip_hlen, len);
return false;
}
igmp_msg = (char *)ip_hdr + ip_hlen;
igmp_msg_len = len - ip_hlen;
msg_type = *igmp_msg;
if (igmp_msg_len < PIM_IGMP_MIN_LEN) {
zlog_warn("IGMP message size=%d shorter than minimum=%d",
igmp_msg_len, PIM_IGMP_MIN_LEN);
@ -514,7 +532,7 @@ bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, int igmp_msg_len,
int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
{
struct ip *ip_hdr;
struct ip *ip_hdr = (struct ip *)buf;
size_t ip_hlen; /* ip header length in bytes */
char *igmp_msg;
int igmp_msg_len;
@ -522,16 +540,8 @@ int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
char from_str[INET_ADDRSTRLEN];
char to_str[INET_ADDRSTRLEN];
ip_hdr = (struct ip *)buf;
ip_hlen = ip_hdr->ip_hl << 2; /* ip_hl gives length in 4-byte words */
if (ip_hlen > len) {
zlog_warn(
"IGMP packet header claims size %zu, but we only have %zu bytes",
ip_hlen, len);
if (!pim_igmp_verify_header(ip_hdr, len, &ip_hlen))
return -1;
}
igmp_msg = buf + ip_hlen;
igmp_msg_len = len - ip_hlen;
@ -547,14 +557,6 @@ int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len)
msg_type, igmp_msg_len);
}
if (!pim_igmp_verify_header(ip_hdr, len, igmp_msg_len, msg_type)) {
zlog_warn(
"Recv IGMP packet from %s to %s on %s: size=%zu ttl=%u msg_type=%d msg_size=%d",
from_str, to_str, igmp->interface->name, len,
ip_hdr->ip_ttl, msg_type, igmp_msg_len);
return -1;
}
switch (msg_type) {
case PIM_IGMP_MEMBERSHIP_QUERY: {
int max_resp_code = igmp_msg[1];

View File

@ -116,8 +116,7 @@ void igmp_sock_delete(struct igmp_sock *igmp);
void igmp_sock_free(struct igmp_sock *igmp);
void igmp_sock_delete_all(struct interface *ifp);
int pim_igmp_packet(struct igmp_sock *igmp, char *buf, size_t len);
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, int igmp_msg_len,
int msg_type);
bool pim_igmp_verify_header(struct ip *ip_hdr, size_t len, size_t *ip_hlen);
void pim_igmp_general_query_on(struct igmp_sock *igmp);
void pim_igmp_general_query_off(struct igmp_sock *igmp);
void pim_igmp_other_querier_timer_on(struct igmp_sock *igmp);