multicast: do not restore deleted record source filter mode to new one

commit 08d3ffcc0cfaba36f6b86fd568cc3bc773061fa6 upstream.

There are two scenarios that we will restore deleted records. The first is
when device down and up(or unmap/remap). In this scenario the new filter
mode is same with previous one. Because we get it from in_dev->mc_list and
we do not touch it during device down and up.

The other scenario is when a new socket join a group which was just delete
and not finish sending status reports. In this scenario, we should use the
current filter mode instead of restore old one. Here are 4 cases in total.

old_socket        new_socket       before_fix       after_fix
  IN(A)             IN(A)           ALLOW(A)         ALLOW(A)
  IN(A)             EX( )           TO_IN( )         TO_EX( )
  EX( )             IN(A)           TO_EX( )         ALLOW(A)
  EX( )             EX( )           TO_EX( )         TO_EX( )

Fixes: 24803f38a5c0b (igmp: do not remove igmp souce list info when set link down)
Fixes: 1666d49e1d416 (mld: do not remove mld souce list info when set link down)
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 337c333f64ae77f23f8034b37020cb235d06e651..08dfaeac1b08641d3f335bd675599ae45cd895c6 100644 (file)
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1159,8 +1159,7 @@ static void igmpv3_del_delrec(struct in_device *in_dev, struct ip_mc_list *im)
        if (pmc) {
                im->interface = pmc->interface;
                im->crcount = in_dev->mr_qrv ?: IGMP_Unsolicited_Report_Count;
-               im->sfmode = pmc->sfmode;
-               if (pmc->sfmode == MCAST_INCLUDE) {
+               if (im->sfmode == MCAST_INCLUDE) {
                        im->tomb = pmc->tomb;
                        im->sources = pmc->sources;
                        for (psf = im->sources; psf; psf = psf->sf_next)

diff --git a/net/ipv6/mcast.c b/net/ipv6/mcast.c
index ee0bee55368af257cc6553690ac9520718ea285e..5c2113badee34fdf1745e4ad31e44475c8eb4a99 100644 (file)
--- a/net/ipv6/mcast.c
+++ b/net/ipv6/mcast.c
@@ -806,8 +806,7 @@ static void mld_del_delrec(struct inet6_dev *idev, struct ifmcaddr6 *im)
        if (pmc) {
                im->idev = pmc->idev;
                im->mca_crcount = idev->mc_qrv;
-               im->mca_sfmode = pmc->mca_sfmode;
-               if (pmc->mca_sfmode == MCAST_INCLUDE) {
+               if (im->mca_sfmode == MCAST_INCLUDE) {
                        im->mca_tomb = pmc->mca_tomb;
                        im->mca_sources = pmc->mca_sources;
                        for (psf = im->mca_sources; psf; psf = psf->sf_next)