4.9-stable review patch. If anyone has any objections, please let me know.
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From: Hangbin Liu liuhangbin@gmail.com
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv4/igmp.c | 3 +-- net/ipv6/mcast.c | 3 +-- 2 files changed, 2 insertions(+), 4 deletions(-)
--- a/net/ipv4/igmp.c +++ b/net/ipv4/igmp.c @@ -1193,8 +1193,7 @@ static void igmpv3_del_delrec(struct in_ if (pmc) { im->interface = pmc->interface; im->crcount = in_dev->mr_qrv ?: net->ipv4.sysctl_igmp_qrv; - 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) --- a/net/ipv6/mcast.c +++ b/net/ipv6/mcast.c @@ -771,8 +771,7 @@ static void mld_del_delrec(struct inet6_ 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)