Author: jch Date: Sun Oct 1 21:20:28 2017 New Revision: 324179 URL: https://svnweb.freebsd.org/changeset/base/324179
Log: Fix an infinite loop in tcp_tw_2msl_scan() when an INP_TIMEWAIT inp has been destroyed before its tcptw with INVARIANTS undefined. This is a symmetric change of r307551: A INP_TIMEWAIT inp should not be destroyed before its tcptw, and INVARIANTS will catch this case. If INVARIANTS is undefined it will emit a log(LOG_ERR) and avoid a hard to debug infinite loop in tcp_tw_2msl_scan(). Reported by: Ben Rubson, hselasky Submitted by: hselasky Tested by: Ben Rubson, jch MFC after: 1 week Sponsored by: Verisign, inc Differential Revision: https://reviews.freebsd.org/D12267 Modified: head/sys/netinet/tcp_timewait.c Modified: head/sys/netinet/tcp_timewait.c ============================================================================== --- head/sys/netinet/tcp_timewait.c Sun Oct 1 20:12:30 2017 (r324178) +++ head/sys/netinet/tcp_timewait.c Sun Oct 1 21:20:28 2017 (r324179) @@ -709,10 +709,29 @@ tcp_tw_2msl_scan(int reuse) INP_WLOCK(inp); tw = intotw(inp); if (in_pcbrele_wlocked(inp)) { - KASSERT(tw == NULL, ("%s: held last inp " - "reference but tw not NULL", __func__)); - INP_INFO_RUNLOCK(&V_tcbinfo); - continue; + if (__predict_true(tw == NULL)) { + INP_INFO_RUNLOCK(&V_tcbinfo); + continue; + } else { + /* This should not happen as in TIMEWAIT + * state the inp should not be destroyed + * before its tcptw. If INVARIANTS is + * defined panic. + */ +#ifdef INVARIANTS + panic("%s: Panic before an infinite " + "loop: INP_TIMEWAIT && (INP_FREED " + "|| inp last reference) && tw != " + "NULL", __func__); +#else + log(LOG_ERR, "%s: Avoid an infinite " + "loop: INP_TIMEWAIT && (INP_FREED " + "|| inp last reference) && tw != " + "NULL", __func__); +#endif + INP_INFO_RUNLOCK(&V_tcbinfo); + break; + } } if (tw == NULL) { _______________________________________________ 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"
