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batman-adv: don't access unregistered net_device object

PATCH Applied Antonio Quartulli 2 participants 2 messages Aug 4, 2015 – Aug 7, 2015 Batman advanced

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Antonio Quartulli

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PATCH 1/1 batman-adv: don't access unregistered net_device object

In batadv_hardif_disable_interface() there is a call to batadv_softif_destroy_sysfs() which in turns invokes unregister_netdevice() on the soft_iface.
After this point we cannot rely on the soft_iface object anymore because it might get free'd by the netdev periodic routine at any time.

For this reason the netdev_upper_dev_unlink(.., soft_iface) call is moved before the invocation of batadv_softif_destroy_sysfs() so that we can be sure that the soft_iface object is still valid.

Signed-off-by Antonio Quartulli <[email protected]>
---
 net/batman-adv/hard-interface.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
net/batman-adv/hard-interface.c +2 -1
index f4a15d2..0565b20 100644
@@ -528,6 +528,8 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 	batadv_purge_outstanding_packets(bat_priv, hard_iface);
 	dev_put(hard_iface->soft_iface);
 
+	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
+
 	/* nobody uses this interface anymore */
 	if (!bat_priv->num_ifaces) {
 		batadv_gw_check_client_stop(bat_priv);

@@ -536,7 +538,6 @@ void batadv_hardif_disable_interface(struct batadv_hard_iface *hard_iface,
 			batadv_softif_destroy_sysfs(hard_iface->soft_iface);
 	}
 
-	netdev_upper_dev_unlink(hard_iface->net_dev, hard_iface->soft_iface);
 	hard_iface->soft_iface = NULL;
 	batadv_hardif_free_ref(hard_iface);
Signature · 1 line
2.5.0
Applied
#1 lore raw
Quoted 7 lines · On Tuesday, August 04, 2015 22:26:19 Antonio Quartulli wrote:

In batadv_hardif_disable_interface() there is a call to batadv_softif_destroy_sysfs() which in turns invokes unregister_netdevice() on the soft_iface.
After this point we cannot rely on the soft_iface object anymore because it might get free'd by the netdev periodic routine at any time.

Quoted 8 lines

For this reason the netdev_upper_dev_unlink(.., soft_iface) call is moved before the invocation of batadv_softif_destroy_sysfs() so that we can be sure that the soft_iface object is still valid.

Signed-off-by Antonio Quartulli <[email protected]>
---
 net/batman-adv/hard-interface.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

Applied in revision 958aafbb.

Thanks,
Marek