ipv6: mcast: fix unsolicited report interval after receiving querys

BugLink: https://bugs.launchpad.net/bugs/1792377

[ Upstream commit 6c6da928 ]

After recieving MLD querys, we update idev->mc_maxdelay with max_delay
from query header. This make the later unsolicited reports have the same
interval with mc_maxdelay, which means we may send unsolicited reports with
long interval time instead of default configured interval time.

Also as we will not call ipv6_mc_reset() after device up. This issue will
be there even after leave the group and join other groups.

Fixes: fc4eba58 ("ipv6: make unsolicited report intervals configurable for mld")
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/ipv6/mcast.c

@@ -2061,7 +2061,8 @@ void ipv6_mc_dad_complete(struct inet6_dev *idev)
 		mld_send_initial_cr(idev);
 		idev->mc_dad_count--;
 		if (idev->mc_dad_count)
-			mld_dad_start_timer(idev, idev->mc_maxdelay);
+			mld_dad_start_timer(idev,
+					    unsolicited_report_interval(idev));
 	}
 }
 
@@ -2073,7 +2074,8 @@ static void mld_dad_timer_expire(unsigned long data)
 	if (idev->mc_dad_count) {
 		idev->mc_dad_count--;
 		if (idev->mc_dad_count)
-			mld_dad_start_timer(idev, idev->mc_maxdelay);
+			mld_dad_start_timer(idev,
+					    unsolicited_report_interval(idev));
 	}
 	in6_dev_put(idev);
 }
@@ -2431,7 +2433,8 @@ static void mld_ifc_timer_expire(unsigned long data)
 	if (idev->mc_ifc_count) {
 		idev->mc_ifc_count--;
 		if (idev->mc_ifc_count)
-			mld_ifc_start_timer(idev, idev->mc_maxdelay);
+			mld_ifc_start_timer(idev,
+					    unsolicited_report_interval(idev));
 	}
 	in6_dev_put(idev);
 }