[PATCH net 0/5] macsec: a few fixes

[PATCH net 0/5] macsec: a few fixes

[Sabrina Dubroca]

Some small fixes for the macsec driver:
 - possible NULL pointer dereferences
 - netlink dumps fixes: RTNL locking, consistent dumps
 - a reference counting bug

Sabrina Dubroca (5):
  macsec: add missing NULL check after kmalloc
  macsec: take rtnl lock before for_each_netdev
  macsec: don't put a NULL rxsa
  macsec: fix rx_sa refcounting with decrypt callback
  macsec: add consistency check to netlink dumps

 drivers/net/macsec.c | 39 +++++++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 14 deletions(-)

-- 
2.8.0

[PATCH net 1/5] macsec: add missing NULL check after kmalloc

[Sabrina Dubroca]

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 drivers/net/macsec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 84d3e5ca8817..f691030ee3df 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1622,8 +1622,8 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct genl_info *info)
 	}
 
 	rx_sa = kmalloc(sizeof(*rx_sa), GFP_KERNEL);
-	if (init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]), secy->key_len,
-		       secy->icv_len)) {
+	if (!rx_sa || init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]),
+				 secy->key_len, secy->icv_len)) {
 		rtnl_unlock();
 		return -ENOMEM;
 	}
-- 
2.8.0

Re: [PATCH net 1/5] macsec: add missing NULL check after kmalloc

[Lance Richardson]

----- Original Message -----
> From: "Sabrina Dubroca" <sd@queasysnail.net>
> To: netdev@vger.kernel.org
> Cc: "Hannes Frederic Sowa" <hannes@stressinduktion.org>, "Johannes Berg" <johannes@sipsolutions.net>, "Dan Carpenter"
> <dan.carpenter@oracle.com>, "Sabrina Dubroca" <sd@queasysnail.net>
> Sent: Tuesday, April 19, 2016 1:36:38 PM
> Subject: [PATCH net 1/5] macsec: add missing NULL check after kmalloc
> 
> Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
> Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
> Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> ---
>  drivers/net/macsec.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
> index 84d3e5ca8817..f691030ee3df 100644
> --- a/drivers/net/macsec.c
> +++ b/drivers/net/macsec.c
> @@ -1622,8 +1622,8 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct
> genl_info *info)
>  	}
>  
>  	rx_sa = kmalloc(sizeof(*rx_sa), GFP_KERNEL);
> -	if (init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]), secy->key_len,
> -		       secy->icv_len)) {
> +	if (!rx_sa || init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]),
> +				 secy->key_len, secy->icv_len)) {

Doesn't this leak rx_sa if kmalloc() succeeds but init_rx_sa fails?

>  		rtnl_unlock();
>  		return -ENOMEM;
>  	}
> --
> 2.8.0
> 
> 

Re: [PATCH net 1/5] macsec: add missing NULL check after kmalloc

[Sabrina Dubroca]

2016-04-19, 13:45:47 -0400, Lance Richardson wrote:
> ----- Original Message -----
> > From: "Sabrina Dubroca" <sd@queasysnail.net>
> > To: netdev@vger.kernel.org
> > Cc: "Hannes Frederic Sowa" <hannes@stressinduktion.org>, "Johannes Berg" <johannes@sipsolutions.net>, "Dan Carpenter"
> > <dan.carpenter@oracle.com>, "Sabrina Dubroca" <sd@queasysnail.net>
> > Sent: Tuesday, April 19, 2016 1:36:38 PM
> > Subject: [PATCH net 1/5] macsec: add missing NULL check after kmalloc
> > 
> > Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
> > Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
> > Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
> > Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
> > ---
> >  drivers/net/macsec.c | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> > 
> > diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
> > index 84d3e5ca8817..f691030ee3df 100644
> > --- a/drivers/net/macsec.c
> > +++ b/drivers/net/macsec.c
> > @@ -1622,8 +1622,8 @@ static int macsec_add_rxsa(struct sk_buff *skb, struct
> > genl_info *info)
> >  	}
> >  
> >  	rx_sa = kmalloc(sizeof(*rx_sa), GFP_KERNEL);
> > -	if (init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]), secy->key_len,
> > -		       secy->icv_len)) {
> > +	if (!rx_sa || init_rx_sa(rx_sa, nla_data(tb_sa[MACSEC_SA_ATTR_KEY]),
> > +				 secy->key_len, secy->icv_len)) {
> 
> Doesn't this leak rx_sa if kmalloc() succeeds but init_rx_sa fails?

Yeah, you're right.  And there's the same code around init_tx_sa.
I'll send v2 tomorrow with this and another fix.

Thanks!

> >  		rtnl_unlock();
> >  		return -ENOMEM;
> >  	}
> > --
> > 2.8.0
> > 
> > 

-- 
Sabrina

[PATCH net 2/5] macsec: take rtnl lock before for_each_netdev

[Sabrina Dubroca]

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Reported-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 drivers/net/macsec.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index f691030ee3df..5f3ea8026074 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2268,8 +2268,6 @@ static int dump_secy(struct macsec_secy *secy, struct net_device *dev,
 	if (!hdr)
 		return -EMSGSIZE;
 
-	rtnl_lock();
-
 	if (nla_put_u32(skb, MACSEC_ATTR_IFINDEX, dev->ifindex))
 		goto nla_put_failure;
 
@@ -2429,14 +2427,11 @@ static int dump_secy(struct macsec_secy *secy, struct net_device *dev,
 
 	nla_nest_end(skb, rxsc_list);
 
-	rtnl_unlock();
-
 	genlmsg_end(skb, hdr);
 
 	return 0;
 
 nla_put_failure:
-	rtnl_unlock();
 	genlmsg_cancel(skb, hdr);
 	return -EMSGSIZE;
 }
@@ -2450,6 +2445,7 @@ static int macsec_dump_txsc(struct sk_buff *skb, struct netlink_callback *cb)
 	dev_idx = cb->args[0];
 
 	d = 0;
+	rtnl_lock();
 	for_each_netdev(net, dev) {
 		struct macsec_secy *secy;
 
@@ -2467,6 +2463,7 @@ next:
 	}
 
 done:
+	rtnl_unlock();
 	cb->args[0] = d;
 	return skb->len;
 }
-- 
2.8.0

[PATCH net 3/5] macsec: don't put a NULL rxsa

[Sabrina Dubroca]

The "deliver:" path of macsec_handle_frame can be called with
rx_sa == NULL.  Check rx_sa != NULL before calling macsec_rxsa_put().

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 drivers/net/macsec.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 5f3ea8026074..2a2136b7d324 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -1161,7 +1161,8 @@ deliver:
 			    macsec_extra_len(macsec_skb_cb(skb)->has_sci));
 	macsec_reset_skb(skb, secy->netdev);
 
-	macsec_rxsa_put(rx_sa);
+	if (rx_sa)
+		macsec_rxsa_put(rx_sa);
 	count_rx(dev, skb->len);
 
 	rcu_read_unlock();
-- 
2.8.0

[PATCH net 4/5] macsec: fix rx_sa refcounting with decrypt callback

[Sabrina Dubroca]

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.

Change macsec_decrypt to return error codes, and use -EINPROGRESS as
an indication that macsec_handle_frame must not release the reference.

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 drivers/net/macsec.c | 16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 2a2136b7d324..1fd2b147fda1 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -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;
-- 
2.8.0

[PATCH net 5/5] macsec: add consistency check to netlink dumps

[Sabrina Dubroca]

Use genl_dump_check_consistent in dump_secy.

Fixes: c09440f7dcb3 ("macsec: introduce IEEE 802.1AE driver")
Suggested-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Acked-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
---
 drivers/net/macsec.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/drivers/net/macsec.c b/drivers/net/macsec.c
index 1fd2b147fda1..41fbe556ba6d 100644
--- a/drivers/net/macsec.c
+++ b/drivers/net/macsec.c
@@ -2271,6 +2271,8 @@ static int dump_secy(struct macsec_secy *secy, struct net_device *dev,
 	if (!hdr)
 		return -EMSGSIZE;
 
+	genl_dump_check_consistent(cb, hdr, &macsec_fam);
+
 	if (nla_put_u32(skb, MACSEC_ATTR_IFINDEX, dev->ifindex))
 		goto nla_put_failure;
 
@@ -2439,6 +2441,8 @@ nla_put_failure:
 	return -EMSGSIZE;
 }
 
+static int macsec_generation = 1; /* protected by RTNL */
+
 static int macsec_dump_txsc(struct sk_buff *skb, struct netlink_callback *cb)
 {
 	struct net *net = sock_net(skb->sk);
@@ -2449,6 +2453,9 @@ static int macsec_dump_txsc(struct sk_buff *skb, struct netlink_callback *cb)
 
 	d = 0;
 	rtnl_lock();
+
+	cb->seq = macsec_generation;
+
 	for_each_netdev(net, dev) {
 		struct macsec_secy *secy;
 
@@ -2920,6 +2927,8 @@ static void macsec_dellink(struct net_device *dev, struct list_head *head)
 	struct net_device *real_dev = macsec->real_dev;
 	struct macsec_rxh_data *rxd = macsec_data_rtnl(real_dev);
 
+	macsec_generation++;
+
 	unregister_netdevice_queue(dev, head);
 	list_del_rcu(&macsec->secys);
 	if (list_empty(&rxd->secys))
@@ -3066,6 +3075,8 @@ static int macsec_newlink(struct net *net, struct net_device *dev,
 	if (err < 0)
 		goto del_dev;
 
+	macsec_generation++;
+
 	dev_hold(real_dev);
 
 	return 0;
-- 
2.8.0