diff options
| author | Antonio Quartulli <antonio@meshcoding.com> | 2014-02-15 21:50:37 +0100 |
|---|---|---|
| committer | Antonio Quartulli <antonio@meshcoding.com> | 2014-02-17 17:17:02 +0100 |
| commit | 70b271a78beba787155d6696aacd7c4d4a251c50 (patch) | |
| tree | bb8f4e8e8f9833d993b8f09638a063d6290f5281 /net | |
| parent | a5a5cb8cab526af2f6cbe9715f8ca843192f0d81 (diff) | |
batman-adv: fix potential kernel paging error for unicast transmissions
batadv_send_skb_prepare_unicast(_4addr) might reallocate the
skb's data. If it does then our ethhdr pointer is not valid
anymore in batadv_send_skb_unicast(), resulting in a kernel
paging error.
Fixing this by refetching the ethhdr pointer after the
potential reallocation.
Signed-off-by: Linus Lüssing <linus.luessing@web.de>
Signed-off-by: Antonio Quartulli <antonio@meshcoding.com>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/send.c | 9 |
1 files changed, 7 insertions, 2 deletions
diff --git a/net/batman-adv/send.c b/net/batman-adv/send.c index 579f5f00a38..843febd1e51 100644 --- a/net/batman-adv/send.c +++ b/net/batman-adv/send.c @@ -254,9 +254,9 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv, struct batadv_orig_node *orig_node, unsigned short vid) { - struct ethhdr *ethhdr = (struct ethhdr *)skb->data; + struct ethhdr *ethhdr; struct batadv_unicast_packet *unicast_packet; - int ret = NET_XMIT_DROP; + int ret = NET_XMIT_DROP, hdr_size; if (!orig_node) goto out; @@ -265,12 +265,16 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv, case BATADV_UNICAST: if (!batadv_send_skb_prepare_unicast(skb, orig_node)) goto out; + + hdr_size = sizeof(*unicast_packet); break; case BATADV_UNICAST_4ADDR: if (!batadv_send_skb_prepare_unicast_4addr(bat_priv, skb, orig_node, packet_subtype)) goto out; + + hdr_size = sizeof(struct batadv_unicast_4addr_packet); break; default: /* this function supports UNICAST and UNICAST_4ADDR only. It @@ -279,6 +283,7 @@ static int batadv_send_skb_unicast(struct batadv_priv *bat_priv, goto out; } + ethhdr = (struct ethhdr *)(skb->data + hdr_size); unicast_packet = (struct batadv_unicast_packet *)skb->data; /* inform the destination node that we are still missing a correct route |