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| author | Sven Eckelmann <sven@narfation.org> | 2016-06-26 11:16:12 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2016-06-29 04:01:48 -0400 |
| commit | 3b55e4422087f9f7b241031d758a0c65584e4297 (patch) | |
| tree | 4e5911b53be006d88af805e05eb1e2b6cf6b1535 /net | |
| parent | baceced93274ff2f846eae991664f9094425ffa8 (diff) | |
| download | linux-3b55e4422087f9f7b241031d758a0c65584e4297.tar.gz linux-3b55e4422087f9f7b241031d758a0c65584e4297.tar.bz2 linux-3b55e4422087f9f7b241031d758a0c65584e4297.zip | |
batman-adv: Fix ICMP RR ethernet access after skb_linearize
The skb_linearize may reallocate the skb. This makes the calculated pointer
for ethhdr invalid. But it the pointer is used later to fill in the RR
field of the batadv_icmp_packet_rr packet.
Instead re-evaluate eth_hdr after the skb_linearize+skb_cow to fix the
pointer and avoid the invalid read.
Fixes: da6b8c20a5b8 ("batman-adv: generalize batman-adv icmp packet handling")
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Marek Lindner <mareklindner@neomailbox.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/batman-adv/routing.c | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/net/batman-adv/routing.c b/net/batman-adv/routing.c index e3857ed4057f..6c2901a86230 100644 --- a/net/batman-adv/routing.c +++ b/net/batman-adv/routing.c @@ -374,6 +374,7 @@ int batadv_recv_icmp_packet(struct sk_buff *skb, if (skb_cow(skb, ETH_HLEN) < 0) goto out; + ethhdr = eth_hdr(skb); icmph = (struct batadv_icmp_header *)skb->data; icmp_packet_rr = (struct batadv_icmp_packet_rr *)icmph; if (icmp_packet_rr->rr_cur >= BATADV_RR_LEN) |