Author: marcel Date: Fri Dec 2 06:15:59 2016 New Revision: 309394 URL: https://svnweb.freebsd.org/changeset/base/309394
Log: Fix use-after-free bugs in pfsync(4) Use after free happens for state that is deleted. The reference count is what prevents the state from being freed. When the state is dequeued, the reference count is dropped and the memory freed. We can't dereference the next pointer or re-queue the state. MFC after: 1 week Differential Revision: https://reviews.freebsd.org/D8671 Modified: head/sys/netpfil/pf/if_pfsync.c Modified: head/sys/netpfil/pf/if_pfsync.c ============================================================================== --- head/sys/netpfil/pf/if_pfsync.c Fri Dec 2 06:07:27 2016 (r309393) +++ head/sys/netpfil/pf/if_pfsync.c Fri Dec 2 06:15:59 2016 (r309394) @@ -1509,7 +1509,7 @@ pfsync_sendout(int schedswi) struct ip *ip; struct pfsync_header *ph; struct pfsync_subheader *subh; - struct pf_state *st; + struct pf_state *st, *st_next; struct pfsync_upd_req_item *ur; int offset; int q, count = 0; @@ -1559,7 +1559,7 @@ pfsync_sendout(int schedswi) offset += sizeof(*subh); count = 0; - TAILQ_FOREACH(st, &sc->sc_qs[q], sync_list) { + TAILQ_FOREACH_SAFE(st, &sc->sc_qs[q], sync_list, st_next) { KASSERT(st->sync_state == q, ("%s: st->sync_state == q", __func__)); @@ -1931,6 +1931,8 @@ pfsync_delete_state(struct pf_state *st) if (sc->sc_len == PFSYNC_MINPKT) callout_reset(&sc->sc_tmo, 1 * hz, pfsync_timeout, V_pfsyncif); + pf_ref_state(st); + switch (st->sync_state) { case PFSYNC_S_INS: /* We never got to tell the world so just forget about it. */ @@ -1950,6 +1952,9 @@ pfsync_delete_state(struct pf_state *st) default: panic("%s: unexpected sync state %d", __func__, st->sync_state); } + + pf_release_state(st); + PFSYNC_UNLOCK(sc); } _______________________________________________ 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"
