Fix garbage IP addresses in UDP log_in_vain messages

If multiple threads emit a UDP log_in_vain message concurrently,
the IP addresses could be garbage due to concurrent usage of a
single string buffer inside inet_ntoa().  Use inet_ntoa_r() with
two stack buffers instead.

Reported by:	Mark Martinec <Mark.Martinec+freebsd@ijs.si>
MFC after:	3 days
Relnotes:	yes
Sponsored by:	Dell EMC
This commit is contained in:
Eric van Gyzen 2017-02-07 18:57:57 +00:00
parent fa841eb67a
commit edf0313b70
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=313401

View File

@ -667,13 +667,13 @@ udp_input(struct mbuf **mp, int *offp, int proto)
INPLOOKUP_RLOCKPCB, ifp, m);
if (inp == NULL) {
if (udp_log_in_vain) {
char buf[4*sizeof "123"];
char src[INET_ADDRSTRLEN];
char dst[INET_ADDRSTRLEN];
strcpy(buf, inet_ntoa(ip->ip_dst));
log(LOG_INFO,
"Connection attempt to UDP %s:%d from %s:%d\n",
buf, ntohs(uh->uh_dport), inet_ntoa(ip->ip_src),
ntohs(uh->uh_sport));
inet_ntoa_r(ip->ip_dst, dst), ntohs(uh->uh_dport),
inet_ntoa_r(ip->ip_src, src), ntohs(uh->uh_sport));
}
UDPSTAT_INC(udps_noport);
if (m->m_flags & (M_BCAST | M_MCAST)) {