batman-adv: Fix multicast TT issues with bogus ROAM flags
authorLinus Lüssing <linus.luessing@c0d3.blue>
Wed, 6 Jun 2018 22:46:24 +0000 (00:46 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Fri, 24 Aug 2018 11:09:05 +0000 (13:09 +0200)
commit04954b2dca347ff9ec47ca9f0baaf5d27b384d10
treee0fe2fb920ae408d4994e03b78de33d0d36809c2
parent44fed77fc7e45e0fe6c41286df9134d747b2bd73
batman-adv: Fix multicast TT issues with bogus ROAM flags

[ Upstream commit a44ebeff6bbd6ef50db41b4195fca87b21aefd20 ]

When a (broken) node wrongly sends multicast TT entries with a ROAM
flag then this causes any receiving node to drop all entries for the
same multicast MAC address announced by other nodes, leading to
packet loss.

Fix this DoS vector by only storing TT sync flags. For multicast TT
non-sync'ing flag bits like ROAM are unused so far anyway.

Fixes: 1d8ab8d3c176 ("batman-adv: Modified forwarding behaviour for multicast packets")
Reported-by: Leonardo Mörlein <me@irrelefant.net>
Signed-off-by: Linus Lüssing <linus.luessing@c0d3.blue>
Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/batman-adv/translation-table.c