From: Nikolay Aleksandrov <redacted>
Date: Tue, 30 Jul 2019 14:21:00 +0300

When permanent entries were introduced by the commit below, they were
exempt from timing out and thus igmp leave wouldn't affect them unless
fast leave was enabled on the port which was added before permanent
entries existed. It shouldn't matter if fast leave is enabled or not
if the user added a permanent entry it shouldn't be deleted on igmp
leave.

 ...

Fixes: ccb1c31a7a87 ("bridge: add flags to distinguish permanent mdb entires")
Signed-off-by: Nikolay Aleksandrov <redacted>

Applied and queued up for -stable.