batman-adv: Avoid WARN_ON timing related checks

Message ID 20210518190027.547508-1-sven@narfation.org (mailing list archive)
State Accepted, archived
Delegated to: Simon Wunderlich
Headers
Series batman-adv: Avoid WARN_ON timing related checks |

Commit Message

Sven Eckelmann May 18, 2021, 7 p.m. UTC
  The soft/batadv interface for a queued OGM can be changed during the time
the OGM was queued for transmission and when the OGM is actually
transmitted by the worker.

But WARN_ON must be used to denote kernel bugs and not to print simple
warnings. A warning can simply be printed using pr_warn.

Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
Reported-by: syzbot+c0b807de416427ff3dd1@syzkaller.appspotmail.com
Fixes: 29b9256e6631 ("batman-adv: consider outgoing interface in OGM sending")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
---
 net/batman-adv/bat_iv_ogm.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
  

Patch

diff --git a/net/batman-adv/bat_iv_ogm.c b/net/batman-adv/bat_iv_ogm.c
index 680def80..12022378 100644
--- a/net/batman-adv/bat_iv_ogm.c
+++ b/net/batman-adv/bat_iv_ogm.c
@@ -409,8 +409,10 @@  static void batadv_iv_ogm_emit(struct batadv_forw_packet *forw_packet)
 	if (WARN_ON(!forw_packet->if_outgoing))
 		return;
 
-	if (WARN_ON(forw_packet->if_outgoing->soft_iface != soft_iface))
+	if (forw_packet->if_outgoing->soft_iface != soft_iface) {
+		pr_warn("%s: soft interface switch for queued OGM\n", __func__);
 		return;
+	}
 
 	if (forw_packet->if_incoming->if_status != BATADV_IF_ACTIVE)
 		return;