Author: tuexen Date: Sat Jul 13 12:45:08 2019 New Revision: 349968 URL: https://svnweb.freebsd.org/changeset/base/349968
Log: r348494 fixes a race in udp_output(). The same race exists in udp_output6(), therefore apply a similar patch to IPv6. Reported by: syzbot+c5ffbc8f14294c7b0...@syzkaller.appspotmail.com Reviewed by: bz@, markj@ MFC after: 2 weeks Sponsored by: Netflix, Inc. Differential Revision: https://reviews.freebsd.org/D20936 Modified: head/sys/netinet6/udp6_usrreq.c Modified: head/sys/netinet6/udp6_usrreq.c ============================================================================== --- head/sys/netinet6/udp6_usrreq.c Sat Jul 13 10:46:01 2019 (r349967) +++ head/sys/netinet6/udp6_usrreq.c Sat Jul 13 12:45:08 2019 (r349968) @@ -742,9 +742,24 @@ udp6_output(struct socket *so, int flags_arg, struct m * - when we are not bound to an address and source port (it is * in6_pcbsetport() which will require the write lock). */ +retry: if (sin6 == NULL || (IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) && inp->inp_lport == 0)) { INP_WLOCK(inp); + /* + * In case we lost a race and another thread bound addr/port + * on the inp we cannot keep the wlock (which still would be + * fine) as further down, based on these values we make + * decisions for the pcbinfo lock. If the locks are not in + * synch the assertions on unlock will fire, hence we go for + * one retry loop. + */ + if (sin6 != NULL && + (!IN6_IS_ADDR_UNSPECIFIED(&inp->in6p_laddr) || + inp->inp_lport != 0)) { + INP_WUNLOCK(inp); + goto retry; + } unlock_inp = UH_WLOCKED; } else { INP_RLOCK(inp); _______________________________________________ svn-src-all@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-all To unsubscribe, send any mail to "svn-src-all-unsubscr...@freebsd.org"
