[1/1] batman-adv: Don't schedule OGM for disabled interface

Message ID 20200306120618.25714-2-sw@simonwunderlich.de (mailing list archive)
State Not Applicable, archived
Delegated to: Simon Wunderlich
Headers
Series [1/1] batman-adv: Don't schedule OGM for disabled interface |

Commit Message

Simon Wunderlich March 6, 2020, 12:06 p.m. UTC
  From: Sven Eckelmann <sven@narfation.org>

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>
---
 net/batman-adv/bat_iv_ogm.c | 4 ++++
 1 file changed, 4 insertions(+)
  

Patch

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index f0209505e41a..a7c8dd7ae513 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -789,6 +789,10 @@  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