From bf0ef794e1973ee6f7c482718a8433e3e1b9ed8c Mon Sep 17 00:00:00 2001 From: Sven Eckelmann Date: Sun, 16 Feb 2020 13:02:06 +0100 Subject: [PATCH] batman-adv: Don't schedule OGM for disabled interface commit 8e8ce08198de193e3d21d42e96945216e3d9ac7f upstream. 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 Cc: Hillf Danton Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/bat_iv_ogm.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c index f594183..0b052ff 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 -- 2.7.4