batman-adv: Avoid WARN on net_device without parent in netns
Sven Eckelmann
maintainerPATCH 1/1 batman-adv: Avoid WARN on net_device without parent in netns
It is not allowed to use WARN* helpers on potential incorrect input from the user or transient problems because systems configured as panic_on_warn will reboot due to such a problem.
A NULL return value of __dev_get_by_index can be caused by various problems which can either be related to the system configuration or problems (incorrectly returned network namespaces) in other (virtual) net_device drivers. batman-adv should not cause a (harmful) WARN in this situation and instead only report it via a simple message.
Fixes 3d48811b27f5 ("batman-adv: prevent using any virtual device created on batman-adv as hard-interface")
Reported-by [email protected]
Reported-by Dmitry Vyukov <[email protected]>
Signed-off-by Sven Eckelmann <[email protected]>
---
Cc: syzbot <[email protected]>
Cc: Dmitry Vyukov <[email protected]>
Cc: [email protected]
--- net/batman-adv/hard-interface.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)
net/batman-adv/hard-interface.c +3 -2
@@ -20,7 +20,6 @@#include "main.h" #include <linux/atomic.h> -#include <linux/bug.h> #include <linux/byteorder/generic.h> #include <linux/errno.h> #include <linux/gfp.h>
@@ -179,8 +178,10 @@ static bool batadv_is_on_batman_iface(const struct net_device *net_dev) parent_dev =__dev_get_by_index ((struct net *)parent_net,dev_get_iflink (net_dev));/* if we got a NULL parent_dev there is something broken.. */ -if (WARN (!parent_dev,"Cannot find parent device" )) +if (!parent_dev) { +pr_err ("Cannot find parent device\n" );return false; + }if (batadv_mutual_parents (net_dev, net, parent_dev, parent_net))return false;
Signature · 1 line
2.19.2