batman-adv: Merge bugfixes from 2022.3

* Fix hang up with small MTU hard-interface

Signed-off-by: Sven Eckelmann <sven@narfation.org>
This commit is contained in:
Sven Eckelmann 2022-11-10 21:31:49 +01:00
parent bbcd264ede
commit e2daa846bd
1 changed files with 43 additions and 0 deletions

View File

@ -0,0 +1,43 @@
From: Shigeru Yoshida <syoshida@redhat.com>
Date: Sat, 20 Aug 2022 12:25:16 +0900
Subject: batman-adv: Fix hang up with small MTU hard-interface
The system hangs up when batman-adv soft-interface is created on
hard-interface with small MTU. For example, the following commands
create batman-adv soft-interface on dummy interface with zero MTU:
# ip link add name dummy0 type dummy
# ip link set mtu 0 dev dummy0
# ip link set up dev dummy0
# ip link add name bat0 type batadv
# ip link set dev dummy0 master bat0
These commands cause the system hang up with the following messages:
[ 90.578925][ T6689] batman_adv: bat0: Adding interface: dummy0
[ 90.580884][ T6689] batman_adv: bat0: The MTU of interface dummy0 is too small (0) to handle the transport of batman-adv packets. Packets going over this interface will be fragmented on layer2 which could impact the performance. Setting the MTU to 1560 would solve the problem.
[ 90.586264][ T6689] batman_adv: bat0: Interface activated: dummy0
[ 90.590061][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
[ 90.595517][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
[ 90.598499][ T6689] batman_adv: bat0: Forced to purge local tt entries to fit new maximum fragment MTU (-320)
This patch fixes this issue by returning error when enabling
hard-interface with small MTU size.
Fixes: 29a2a3dc52f4 ("hard interface rewrite")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Origin: upstream, https://git.open-mesh.org/batman-adv.git/commit/a124b52ebab91ac416cf7ba05e671cbb860f30e8
--- a/net/batman-adv/hard-interface.c
+++ b/net/batman-adv/hard-interface.c
@@ -729,6 +729,9 @@ int batadv_hardif_enable_interface(struc
int max_header_len = batadv_max_header_len();
int ret;
+ if (hard_iface->net_dev->mtu < ETH_MIN_MTU + max_header_len)
+ return -EINVAL;
+
if (hard_iface->if_status != BATADV_IF_NOT_IN_USE)
goto out;