--- /dev/null
+From: Sven Eckelmann <sven@narfation.org>
+Date: Sun, 16 Feb 2020 13:02:06 +0100
+Subject: batman-adv: Don't schedule OGM for disabled interface
+
+A transmission scheduling for an interface which is currently dropped by
+batadv_iv_ogm_iface_disable could still be in progress. The B.A.T.M.A.N. V
+is simply cancelling the workqueue item in an synchronous way but this is
+not possible with B.A.T.M.A.N. IV because the OGM submissions are
+intertwined.
+
+Instead it has to stop submitting the OGM when it detect that the buffer
+pointer is set to NULL.
+
+Reported-by: syzbot+a98f2016f40b9cd3818a@syzkaller.appspotmail.com
+Reported-by: syzbot+ac36b6a33c28a491e929@syzkaller.appspotmail.com
+Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
+Signed-off-by: Sven Eckelmann <sven@narfation.org>
+Cc: Hillf Danton <hdanton@sina.com>
+Signed-off-by: Simon Wunderlich <sw@simonwunderlich.de>
+
+Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/a089c55ca004b396d340baae58abe9a79f32cc0f
+
+diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
+index f5941837c3ad463f276cffdb25f9b6cd87af0e92..0b052ff51bdeb36f7eac9abca927e267533d2930 100644
+--- a/net/batman-adv/bat_iv_ogm.c
++++ b/net/batman-adv/bat_iv_ogm.c
+@@ -970,6 +970,10 @@ static void batadv_iv_ogm_schedule_buff(struct batadv_hard_iface *hard_iface)
+
+ lockdep_assert_held(&hard_iface->bat_iv.ogm_buff_mutex);
+
++ /* interface already disabled by batadv_iv_ogm_iface_disable */
++ if (!*ogm_buff)
++ return;
++
+ /* the interface gets activated here to avoid race conditions between
+ * the moment of activating the interface in
+ * hardif_activate_interface() where the originator mac is set and