On 4/21/16, 11:06 AM, "owner-src-committ...@freebsd.org on behalf of Jonathan T. Looney" <owner-src-committ...@freebsd.org on behalf of j...@freebsd.org> wrote:
>Author: jtl >Date: Thu Apr 21 15:06:53 2016 >New Revision: 298408 >URL: https://svnweb.freebsd.org/changeset/base/298408 > >Log: > Prevent underflows in tp->snd_wnd if the remote side ACKs more than > tp->snd_wnd. This can happen, for example, when the remote side responds to > a window probe by ACKing the one byte it contains. > > Differential Revision: https://reviews.freebsd.org/D5625 > Reviewed by: hiren > Obtained from: Juniper Networks (earlier version) > MFC after: 2 weeks > Sponsored by: Juniper Networks This should also have said: Submitted by: srushti.g...@gmail.com (earlier version) Jonathan > >Modified: > head/sys/netinet/tcp_input.c > >Modified: head/sys/netinet/tcp_input.c >============================================================================== >--- head/sys/netinet/tcp_input.c Thu Apr 21 15:02:57 2016 >(r298407) >+++ head/sys/netinet/tcp_input.c Thu Apr 21 15:06:53 2016 >(r298408) >@@ -2754,6 +2754,9 @@ process_ACK: > INP_WLOCK_ASSERT(tp->t_inpcb); > > acked = BYTES_THIS_ACK(tp, th); >+ KASSERT(acked >= 0, ("%s: acked unexepectedly negative " >+ "(tp->snd_una=%u, th->th_ack=%u, tp=%p, m=%p)", __func__, >+ tp->snd_una, th->th_ack, tp, m)); > TCPSTAT_INC(tcps_rcvackpack); > TCPSTAT_ADD(tcps_rcvackbyte, acked); > >@@ -2823,13 +2826,19 @@ process_ACK: > > SOCKBUF_LOCK(&so->so_snd); > if (acked > sbavail(&so->so_snd)) { >- tp->snd_wnd -= sbavail(&so->so_snd); >+ if (tp->snd_wnd >= sbavail(&so->so_snd)) >+ tp->snd_wnd -= sbavail(&so->so_snd); >+ else >+ tp->snd_wnd = 0; > mfree = sbcut_locked(&so->so_snd, > (int)sbavail(&so->so_snd)); > ourfinisacked = 1; > } else { > mfree = sbcut_locked(&so->so_snd, acked); >- tp->snd_wnd -= acked; >+ if (tp->snd_wnd >= (u_long) acked) >+ tp->snd_wnd -= acked; >+ else >+ tp->snd_wnd = 0; > ourfinisacked = 0; > } > /* NB: sowwakeup_locked() does an implicit unlock. */ > > _______________________________________________ svn-src-head@freebsd.org mailing list https://lists.freebsd.org/mailman/listinfo/svn-src-head To unsubscribe, send any mail to "svn-src-head-unsubscr...@freebsd.org"
