6.4-stable review patch. If anyone has any objections, please let me know.
------------------
From: Sven Eckelmann <sven@xxxxxxxxxxxxx>
commit c6a953cce8d0438391e6da48c8d0793d3fbfcfa6 upstream.
If an interface changes the MTU, it is expected that an NETDEV_PRECHANGEMTU
and NETDEV_CHANGEMTU notification events is triggered. This worked fine for
.ndo_change_mtu based changes because core networking code took care of it.
But for auto-adjustments after hard-interfaces changes, these events were
simply missing.
Due to this problem, non-batman-adv components weren't aware of MTU changes
and thus couldn't perform their own tasks correctly.
Fixes: c6c8fea29769 ("net: Add batman-adv meshing protocol")
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Sven Eckelmann <sven@xxxxxxxxxxxxx>
Signed-off-by: Simon Wunderlich <sw@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/batman-adv/hard-interface.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -630,7 +630,7 @@ out:
*/
void batadv_update_min_mtu(struct net_device *soft_iface)
{
- soft_iface->mtu = batadv_hardif_min_mtu(soft_iface);
+ dev_set_mtu(soft_iface, batadv_hardif_min_mtu(soft_iface));
/* Check if the local translate table should be cleaned up to match a
* new (and smaller) MTU.
