rps: flow_dissector: Fix uninitialized flow_keys used in __skb_get_hash possibly

The original codes depend on that the function parameters are evaluated from
left to right. But the parameter's evaluation order is not defined in C
standard actually.

When flow_keys_have_l4(&keys) is invoked before ___skb_get_hash(skb, &keys,
hashrnd) with some compilers or environment, the keys passed to
flow_keys_have_l4 is not initialized.

Fixes: 6db61d79c1 ("flow_dissector: Ignore flow dissector return value from ___skb_get_hash")

Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Gao Feng <fgao@ikuai8.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Gao Feng 2016-08-31 14:15:05 +08:00 committed by David S. Miller
parent 28b346cbc0
commit 635c223cfa

View File

@ -680,11 +680,13 @@ EXPORT_SYMBOL_GPL(__skb_get_hash_symmetric);
void __skb_get_hash(struct sk_buff *skb)
{
struct flow_keys keys;
u32 hash;
__flow_hash_secret_init();
__skb_set_sw_hash(skb, ___skb_get_hash(skb, &keys, hashrnd),
flow_keys_have_l4(&keys));
hash = ___skb_get_hash(skb, &keys, hashrnd);
__skb_set_sw_hash(skb, hash, flow_keys_have_l4(&keys));
}
EXPORT_SYMBOL(__skb_get_hash);