Header pointers needs to be reinitialized in icmp_error after m_pullup calls: Date: Thu Sep 28 15:06:28 2017 -0700 Reinitialize mtod derived protocol header pointers in icmp_error after calling m_pullup diff --git a/sys/netinet/ip_icmp.c b/sys/netinet/ip_icmp.c index 5983b3386af..4f466236864 100644 --- a/sys/netinet/ip_icmp.c +++ b/sys/netinet/ip_icmp.c @@ -237,6 +237,12 @@ icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) if (n->m_len < oiphlen + sizeof(struct tcphdr) && ((n = m_pullup(n, oiphlen + sizeof(struct tcphdr))) == NULL)) goto freeit; + + /* + * Reinitialize pointers derived from mbuf data pointer, + * after calling m_pullup + */ + oip = mtod(n, struct ip *); th = (struct tcphdr *)((caddr_t)oip + oiphlen); tcphlen = th->th_off << 2; if (tcphlen < sizeof(struct tcphdr)) @@ -248,6 +254,14 @@ icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) if (n->m_len < oiphlen + tcphlen && ((n = m_pullup(n, oiphlen + tcphlen)) == NULL)) goto freeit; + + /* + * Reinitialize pointers derived from mbuf data pointer, + * after calling m_pullup + */ + oip = mtod(n, struct ip *); + th = (struct tcphdr *)((caddr_t)oip + oiphlen); + icmpelen = max(tcphlen, min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); } else if (oip->ip_p == IPPROTO_SCTP) { @@ -262,6 +276,12 @@ icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) if (n->m_len < oiphlen + sizeof(struct sctphdr) && (n = m_pullup(n, oiphlen + sizeof(struct sctphdr))) == NULL) goto freeit; + + /* + * Reinitialize pointers derived from mbuf data pointer, + * after calling m_pullup + */ + oip = mtod(n, struct ip *); icmpelen = max(sizeof(struct sctphdr), min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen)); sh = (struct sctphdr *)((caddr_t)oip + oiphlen); @@ -272,7 +292,15 @@ icmp_error(struct mbuf *n, int type, int code, uint32_t dest, int mtu) if (n->m_len < oiphlen + sizeof(struct sctphdr) + 8 && (n = m_pullup(n, oiphlen + sizeof(struct sctphdr) + 8)) == NULL) goto freeit; + + /* + * Reinitialize pointers derived from mbuf data pointer, + * after calling m_pullup + */ + oip = mtod(n, struct ip *); + sh = (struct sctphdr *)((caddr_t)oip + oiphlen); ch = (struct sctp_chunkhdr *)(sh + 1); + if (ch->chunk_type == SCTP_INITIATION) { icmpelen = max(sizeof(struct sctphdr) + 8, min(V_icmp_quotelen, ntohs(oip->ip_len) - oiphlen));
A commit references this bug: Author: ae Date: Fri Sep 29 06:24:45 UTC 2017 New revision: 324098 URL: https://svnweb.freebsd.org/changeset/base/324098 Log: Some mbuf related fixes in icmp_error() * check mbuf length before doing mtod() and accessing to IP header; * update oip pointer and all depending pointers after m_pullup(); * remove extra checks and extra parentheses, wrap long lines; PR: 222670 Reported by: Prabhakar Lakhera MFC after: 1 week Changes: head/sys/netinet/ip_icmp.c
A commit references this bug: Author: ae Date: Mon Oct 9 08:50:04 UTC 2017 New revision: 324426 URL: https://svnweb.freebsd.org/changeset/base/324426 Log: MFC r324098: Some mbuf related fixes in icmp_error() * check mbuf length before doing mtod() and accessing to IP header; * update oip pointer and all depending pointers after m_pullup(); * remove extra checks and extra parentheses, wrap long lines; PR: 222670 Changes: _U stable/11/ stable/11/sys/netinet/ip_icmp.c