macsec: fix rx_sa refcounting with decrypt callback

The decrypt callback macsec_decrypt_done needs a reference on the rx_sa
and releases it before returning, but macsec_handle_frame already
put that reference after macsec_decrypt returned NULL.

Set rx_sa to NULL when the decrypt callback runs so that
macsec_handle_frame knows it must not release the reference.

Fixes: c09440f7dc ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Sabrina Dubroca 2016-04-22 11:28:04 +02:00 committed by David S. Miller
parent 497f358aa4
commit c3b7d0bd7a

View File

@ -880,12 +880,12 @@ static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
macsec_skb_cb(skb)->valid = false;
skb = skb_share_check(skb, GFP_ATOMIC);
if (!skb)
return NULL;
return ERR_PTR(-ENOMEM);
req = aead_request_alloc(rx_sa->key.tfm, GFP_ATOMIC);
if (!req) {
kfree_skb(skb);
return NULL;
return ERR_PTR(-ENOMEM);
}
hdr = (struct macsec_eth_header *)skb->data;
@ -905,7 +905,7 @@ static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
skb = skb_unshare(skb, GFP_ATOMIC);
if (!skb) {
aead_request_free(req);
return NULL;
return ERR_PTR(-ENOMEM);
}
} else {
/* integrity only: all headers + data authenticated */
@ -921,14 +921,14 @@ static struct sk_buff *macsec_decrypt(struct sk_buff *skb,
dev_hold(dev);
ret = crypto_aead_decrypt(req);
if (ret == -EINPROGRESS) {
return NULL;
return ERR_PTR(ret);
} else if (ret != 0) {
/* decryption/authentication failed
* 10.6 if validateFrames is disabled, deliver anyway
*/
if (ret != -EBADMSG) {
kfree_skb(skb);
skb = NULL;
skb = ERR_PTR(ret);
}
} else {
macsec_skb_cb(skb)->valid = true;
@ -1146,8 +1146,10 @@ static rx_handler_result_t macsec_handle_frame(struct sk_buff **pskb)
secy->validate_frames != MACSEC_VALIDATE_DISABLED)
skb = macsec_decrypt(skb, dev, rx_sa, sci, secy);
if (!skb) {
macsec_rxsa_put(rx_sa);
if (IS_ERR(skb)) {
/* the decrypt callback needs the reference */
if (PTR_ERR(skb) != -EINPROGRESS)
macsec_rxsa_put(rx_sa);
rcu_read_unlock();
*pskb = NULL;
return RX_HANDLER_CONSUMED;