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| author | xeb@mail.ru <xeb@mail.ru> | 2011-07-22 20:49:40 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2011-07-23 20:06:00 -0700 |
| commit | 559fafb94ad9e4cd8774f39241917c57396f9fc5 (patch) | |
| tree | f1c255fff42f8429ba3d17f4a7e19f1cc8cfe338 /net | |
| parent | b0fe4a31849063fcac0bdc93716ca92615e93f57 (diff) | |
| download | linux-559fafb94ad9e4cd8774f39241917c57396f9fc5.tar.gz linux-559fafb94ad9e4cd8774f39241917c57396f9fc5.tar.bz2 linux-559fafb94ad9e4cd8774f39241917c57396f9fc5.zip | |
gre: fix improper error handling
Fix improper protocol err_handler, current implementation is fully
unapplicable and may cause kernel crash due to double kfree_skb.
Signed-off-by: Dmitry Kozlov <xeb@mail.ru>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net')
| -rw-r--r-- | net/ipv4/gre.c | 21 |
1 files changed, 6 insertions, 15 deletions
diff --git a/net/ipv4/gre.c b/net/ipv4/gre.c index 9dbe10875fbd..dbfc21de3479 100644 --- a/net/ipv4/gre.c +++ b/net/ipv4/gre.c @@ -15,6 +15,7 @@ #include <linux/kmod.h> #include <linux/skbuff.h> #include <linux/in.h> +#include <linux/ip.h> #include <linux/netdevice.h> #include <linux/spinlock.h> #include <net/protocol.h> @@ -96,27 +97,17 @@ drop: static void gre_err(struct sk_buff *skb, u32 info) { const struct gre_protocol *proto; - u8 ver; - - if (!pskb_may_pull(skb, 12)) - goto drop; + const struct iphdr *iph = (const struct iphdr *)skb->data; + u8 ver = skb->data[(iph->ihl<<2) + 1]&0x7f; - ver = skb->data[1]&0x7f; if (ver >= GREPROTO_MAX) - goto drop; + return; rcu_read_lock(); proto = rcu_dereference(gre_proto[ver]); - if (!proto || !proto->err_handler) - goto drop_unlock; - proto->err_handler(skb, info); - rcu_read_unlock(); - return; - -drop_unlock: + if (proto && proto->err_handler) + proto->err_handler(skb, info); rcu_read_unlock(); -drop: - kfree_skb(skb); } static const struct net_protocol net_gre_protocol = { |