batman-adv: Don't write in not allocated packet_buff
Commit Message
Each net_device in a system will automatically managed as a possible
batman_if and holds different informations like a buffer with a prepared
originator messages. To reduce the memory usage, the packet_buff will
only be allocated when the interface is really added/enabled for
batman-adv.
The function to update the hw address information inside the packet_buff
just assumes that the packet_buff is always initialised and thus the
kernel will just oops when we try to change the hw address of a not
already fully enabled interface.
We must always check if the packet_buff is allocated before we try to
change information inside of it.
Reported-by: Tim Glaremin <Tim.Glaremin@web.de>
Reported-by: Lemonde <zukky@bb.banban.jp>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
Cc: stable <stable@kernel.org>
Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
---
batman-adv/hard-interface.c | 4 ++++
1 files changed, 4 insertions(+), 0 deletions(-)
Comments
Sven Eckelmann wrote:
> Each net_device in a system will automatically managed as a possible
> batman_if and holds different informations like a buffer with a prepared
> originator messages. To reduce the memory usage, the packet_buff will
> only be allocated when the interface is really added/enabled for
> batman-adv.
>
> The function to update the hw address information inside the packet_buff
> just assumes that the packet_buff is always initialised and thus the
> kernel will just oops when we try to change the hw address of a not
> already fully enabled interface.
>
> We must always check if the packet_buff is allocated before we try to
> change information inside of it.
>
> Reported-by: Tim Glaremin <Tim.Glaremin@web.de>
> Reported-by: Lemonde <zukky@bb.banban.jp>
> Signed-off-by: Sven Eckelmann <sven.eckelmann@gmx.de>
> Cc: stable <stable@kernel.org>
Before there is a wrong impression. This bug was indirectly already fixed in
trunk by "batman-adv: attach each hard-interface to a soft-interface". So it
is not a must have. maint/next got the patch now and I hope that
openwrt/debian will have them soon too.
But I will send it for the stable kernel tree now and change the patch
"batman-adv: attach each hard-interface to a soft-interface" in master-rebase
to remove those changes again.
Best regards,
Sven
@@ -138,6 +138,9 @@ static bool hardif_is_iface_up(struct batman_if *batman_if)
static void update_mac_addresses(struct batman_if *batman_if)
{
+ if (!batman_if || !batman_if->packet_buff)
+ return;
+
addr_to_string(batman_if->addr_str, batman_if->net_dev->dev_addr);
memcpy(((struct batman_packet *)(batman_if->packet_buff))->orig,
@@ -397,6 +400,7 @@ static struct batman_if *hardif_add_interface(struct net_device *net_dev)
batman_if->net_dev = net_dev;
batman_if->soft_iface = NULL;
batman_if->if_status = IF_NOT_IN_USE;
+ batman_if->packet_buff = NULL;
INIT_LIST_HEAD(&batman_if->list);
check_known_mac_addr(batman_if->net_dev->dev_addr);