diff mbox

[RFC] Smack: Fix handling of IPv4 traffic received by PF_INET6 sockets

Message ID 20180710070515eucas1p1dddc12cc44c820971809a242e8cee106~-8AfqiO9s0149301493eucas1p1h@eucas1p1.samsung.com (mailing list archive)
State New, archived
Headers show

Commit Message

Piotr Sawicki July 10, 2018, 7:05 a.m. UTC
A socket which has sk_family set to PF_INET6 is able to receive not
only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).

Prior to this patch, the smk_skb_to_addr_ipv6() could have been
called for socket buffers containing IPv4 packets, in result such
traffic was allowed.

Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
---
  security/smack/smack_lsm.c | 12 ++++++++----
  1 file changed, 8 insertions(+), 4 deletions(-)

  		/*
@@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
*sk, struct sk_buff *skb)
  		 */
  		netlbl_secattr_init(&secattr);

-		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
+		rc = netlbl_skbuff_getattr(skb, family, &secattr);
  		if (rc == 0)
  			skp = smack_from_secattr(&secattr, ssp);
  		else
@@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
*sk, struct sk_buff *skb)
  #endif
  #ifdef CONFIG_AUDIT
  		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
-		ad.a.u.net->family = sk->sk_family;
+		ad.a.u.net->family = family;
  		ad.a.u.net->netif = skb->skb_iif;
  		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
  #endif
@@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
*sk, struct sk_buff *skb)
  		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
  					MAY_WRITE, rc);
  		if (rc != 0)
-			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
+			netlbl_skbuff_err(skb, family, rc, 0);
  		break;
  #if IS_ENABLED(CONFIG_IPV6)
  	case PF_INET6:

Comments

Casey Schaufler July 10, 2018, 3:21 p.m. UTC | #1
On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
> A socket which has sk_family set to PF_INET6 is able to receive not
> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>
> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
> called for socket buffers containing IPv4 packets, in result such
> traffic was allowed.
>
> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>

Looks fine from here. Do you have a simple test case?

> ---
>   security/smack/smack_lsm.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 19de675..1315de4 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   	struct smack_known *skp = NULL;
>   	int rc = 0;
>   	struct smk_audit_info ad;
> +	u16 family = sk->sk_family;
>   #ifdef CONFIG_AUDIT
>   	struct lsm_network_audit net;
>   #endif
>   #if IS_ENABLED(CONFIG_IPV6)
>   	struct sockaddr_in6 sadd;
>   	int proto;
> +
> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
> +		family = PF_INET;
>   #endif /* CONFIG_IPV6 */
>
> -	switch (sk->sk_family) {
> +	switch (family) {
>   	case PF_INET:
>   #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>   		/*
> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   		 */
>   		netlbl_secattr_init(&secattr);
>
> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>   		if (rc == 0)
>   			skp = smack_from_secattr(&secattr, ssp);
>   		else
> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   #endif
>   #ifdef CONFIG_AUDIT
>   		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
> -		ad.a.u.net->family = sk->sk_family;
> +		ad.a.u.net->family = family;
>   		ad.a.u.net->netif = skb->skb_iif;
>   		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>   #endif
> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>   					MAY_WRITE, rc);
>   		if (rc != 0)
> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
> +			netlbl_skbuff_err(skb, family, rc, 0);
>   		break;
>   #if IS_ENABLED(CONFIG_IPV6)
>   	case PF_INET6:

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Piotr Sawicki July 10, 2018, 3:44 p.m. UTC | #2
On 07/10/2018 05:21 PM, Casey Schaufler wrote:
> On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
>> A socket which has sk_family set to PF_INET6 is able to receive not
>> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>>
>> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
>> called for socket buffers containing IPv4 packets, in result such
>> traffic was allowed.
>>
>> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
> 
> Looks fine from here. Do you have a simple test case?


Yes, I've tested it on Tizen emulator.

Tests are available here 
https://review.tizen.org/gerrit/#/admin/projects/platform/core/test/security-tests, 
branch nether.

I'm really sorry for this mess with multiple emails.


>> ---
>>    security/smack/smack_lsm.c | 12 ++++++++----
>>    1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>> index 19de675..1315de4 100644
>> --- a/security/smack/smack_lsm.c
>> +++ b/security/smack/smack_lsm.c
>> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    	struct smack_known *skp = NULL;
>>    	int rc = 0;
>>    	struct smk_audit_info ad;
>> +	u16 family = sk->sk_family;
>>    #ifdef CONFIG_AUDIT
>>    	struct lsm_network_audit net;
>>    #endif
>>    #if IS_ENABLED(CONFIG_IPV6)
>>    	struct sockaddr_in6 sadd;
>>    	int proto;
>> +
>> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
>> +		family = PF_INET;
>>    #endif /* CONFIG_IPV6 */
>>
>> -	switch (sk->sk_family) {
>> +	switch (family) {
>>    	case PF_INET:
>>    #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>>    		/*
>> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    		 */
>>    		netlbl_secattr_init(&secattr);
>>
>> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
>> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>>    		if (rc == 0)
>>    			skp = smack_from_secattr(&secattr, ssp);
>>    		else
>> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    #endif
>>    #ifdef CONFIG_AUDIT
>>    		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
>> -		ad.a.u.net->family = sk->sk_family;
>> +		ad.a.u.net->family = family;
>>    		ad.a.u.net->netif = skb->skb_iif;
>>    		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>>    #endif
>> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>>    					MAY_WRITE, rc);
>>    		if (rc != 0)
>> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
>> +			netlbl_skbuff_err(skb, family, rc, 0);
>>    		break;
>>    #if IS_ENABLED(CONFIG_IPV6)
>>    	case PF_INET6:
> 
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> 
> 
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Casey Schaufler July 10, 2018, 4:16 p.m. UTC | #3
On 7/10/2018 8:44 AM, Piotr Sawicki wrote:
> On 07/10/2018 05:21 PM, Casey Schaufler wrote:
>> On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
>>> A socket which has sk_family set to PF_INET6 is able to receive not
>>> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>>>
>>> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
>>> called for socket buffers containing IPv4 packets, in result such
>>> traffic was allowed.
>>>
>>> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
>> Looks fine from here. Do you have a simple test case?
>
> Yes, I've tested it on Tizen emulator.
>
> Tests are available here 
> https://review.tizen.org/gerrit/#/admin/projects/platform/core/test/security-tests, 
> branch nether.

Can you identify the specific test? There's quite a bit to look through.
Thank you.

>
> I'm really sorry for this mess with multiple emails.
>
>
>>> ---
>>>    security/smack/smack_lsm.c | 12 ++++++++----
>>>    1 file changed, 8 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>>> index 19de675..1315de4 100644
>>> --- a/security/smack/smack_lsm.c
>>> +++ b/security/smack/smack_lsm.c
>>> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    	struct smack_known *skp = NULL;
>>>    	int rc = 0;
>>>    	struct smk_audit_info ad;
>>> +	u16 family = sk->sk_family;
>>>    #ifdef CONFIG_AUDIT
>>>    	struct lsm_network_audit net;
>>>    #endif
>>>    #if IS_ENABLED(CONFIG_IPV6)
>>>    	struct sockaddr_in6 sadd;
>>>    	int proto;
>>> +
>>> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
>>> +		family = PF_INET;
>>>    #endif /* CONFIG_IPV6 */
>>>
>>> -	switch (sk->sk_family) {
>>> +	switch (family) {
>>>    	case PF_INET:
>>>    #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>>>    		/*
>>> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    		 */
>>>    		netlbl_secattr_init(&secattr);
>>>
>>> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
>>> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>>>    		if (rc == 0)
>>>    			skp = smack_from_secattr(&secattr, ssp);
>>>    		else
>>> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    #endif
>>>    #ifdef CONFIG_AUDIT
>>>    		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
>>> -		ad.a.u.net->family = sk->sk_family;
>>> +		ad.a.u.net->family = family;
>>>    		ad.a.u.net->netif = skb->skb_iif;
>>>    		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>>>    #endif
>>> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>>>    					MAY_WRITE, rc);
>>>    		if (rc != 0)
>>> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
>>> +			netlbl_skbuff_err(skb, family, rc, 0);
>>>    		break;
>>>    #if IS_ENABLED(CONFIG_IPV6)
>>>    	case PF_INET6:
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>>
>>
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Piotr Sawicki July 11, 2018, 7:38 a.m. UTC | #4
On 07/10/2018 06:16 PM, Casey Schaufler wrote:
> On 7/10/2018 8:44 AM, Piotr Sawicki wrote:
>> On 07/10/2018 05:21 PM, Casey Schaufler wrote:
>>> On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
>>>> A socket which has sk_family set to PF_INET6 is able to receive not
>>>> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>>>>
>>>> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
>>>> called for socket buffers containing IPv4 packets, in result such
>>>> traffic was allowed.
>>>>
>>>> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
>>> Looks fine from here. Do you have a simple test case?
>>
>> Yes, I've tested it on Tizen emulator.
>>
>> Tests are available here
>> https://review.tizen.org/gerrit/#/admin/projects/platform/core/test/security-tests,
>> branch nether.
> 
> Can you identify the specific test? There's quite a bit to look through.
> Thank you.

ID:NETHER_IPV6_IPV4_LOCAL_INTER_APP_CONNECTION:nether_check_ipv6_srv_ipv4_udp_local_inter_app_connection_internet_access_granted
ID:NETHER_IPV6_IPV4_LOCAL_INTER_APP_CONNECTION:nether_check_ipv6_srv_ipv4_udp_local_inter_app_connection_internet_access_denied

It's a new thing, so tests are still in review: 
https://review.tizen.org/gerrit/#/c/183458/

To run the tests on the emulator you need to apply also these patches:
(Nether) https://review.tizen.org/gerrit/#/c/183464/ and turn on IPv6 
connection tracking in the kernel. I've used a kernel downloaded from 
https://review.tizen.org/gerrit/#/admin/projects/sdk/emulator/emulator-kernel 
branch tizen.

I know that these tests are Tizen specific, and it might be really time 
consuming to prepare an environment for them. So, I propose to just use 
the netcat tool and run one of its instances as a UDP server listening 
on IPv6 address [::] and the second one as a IPV4 client.

e.g.
server: nc -6 -l -u 20000
client: nc -u 127.0.0.1 20000

In case of TCP connections, access is properly checked in 
smack_inet_conn_request(). But when IPv4-mapped IPv6 addresses are used 
and two processes have write access to each other, 
smack_socket_sock_rcv_skb() will call smk_skb_to_addr_ipv6() function 
for IPv4 packets.





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Casey Schaufler July 16, 2018, 11:33 p.m. UTC | #5
On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
> A socket which has sk_family set to PF_INET6 is able to receive not
> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>
> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
> called for socket buffers containing IPv4 packets, in result such
> traffic was allowed.
>
> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>

Acked-by: Casey Schaufler <casey@schaufler-ca.com

I have added this to git://github.com/cschaufler/next-smack#smack-for-4.19
after doing a little whitespace clean-up and removal of unnecessary braces.

> ---
>   security/smack/smack_lsm.c | 12 ++++++++----
>   1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
> index 19de675..1315de4 100644
> --- a/security/smack/smack_lsm.c
> +++ b/security/smack/smack_lsm.c
> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   	struct smack_known *skp = NULL;
>   	int rc = 0;
>   	struct smk_audit_info ad;
> +	u16 family = sk->sk_family;
>   #ifdef CONFIG_AUDIT
>   	struct lsm_network_audit net;
>   #endif
>   #if IS_ENABLED(CONFIG_IPV6)
>   	struct sockaddr_in6 sadd;
>   	int proto;
> +
> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
> +		family = PF_INET;
>   #endif /* CONFIG_IPV6 */
>
> -	switch (sk->sk_family) {
> +	switch (family) {
>   	case PF_INET:
>   #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>   		/*
> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   		 */
>   		netlbl_secattr_init(&secattr);
>
> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>   		if (rc == 0)
>   			skp = smack_from_secattr(&secattr, ssp);
>   		else
> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   #endif
>   #ifdef CONFIG_AUDIT
>   		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
> -		ad.a.u.net->family = sk->sk_family;
> +		ad.a.u.net->family = family;
>   		ad.a.u.net->netif = skb->skb_iif;
>   		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>   #endif
> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock 
> *sk, struct sk_buff *skb)
>   		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>   					MAY_WRITE, rc);
>   		if (rc != 0)
> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
> +			netlbl_skbuff_err(skb, family, rc, 0);
>   		break;
>   #if IS_ENABLED(CONFIG_IPV6)
>   	case PF_INET6:

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Piotr Sawicki July 17, 2018, 10:28 a.m. UTC | #6
On 07/17/2018 01:33 AM, Casey Schaufler wrote:
> On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
>> A socket which has sk_family set to PF_INET6 is able to receive not
>> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>>
>> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
>> called for socket buffers containing IPv4 packets, in result such
>> traffic was allowed.
>>
>> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
> 
> Acked-by: Casey Schaufler <casey@schaufler-ca.com
> 
> I have added this to git://github.com/cschaufler/next-smack#smack-for-4.19
> after doing a little whitespace clean-up and removal of unnecessary braces.

I see that the wrong version of the patch was applied. It should be a 
version taken from the email titled "[PATCH RFC] Smack: Fix handling of 
IPv4 traffic received by PF_INET6 sockets" (10th of July 2018). The 
family variable should be used also in netlbl_skbuff_getattr(), 
netlbl_skbuff_err and in audit structure.


>> ---
>>    security/smack/smack_lsm.c | 12 ++++++++----
>>    1 file changed, 8 insertions(+), 4 deletions(-)
>>
>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>> index 19de675..1315de4 100644
>> --- a/security/smack/smack_lsm.c
>> +++ b/security/smack/smack_lsm.c
>> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    	struct smack_known *skp = NULL;
>>    	int rc = 0;
>>    	struct smk_audit_info ad;
>> +	u16 family = sk->sk_family;
>>    #ifdef CONFIG_AUDIT
>>    	struct lsm_network_audit net;
>>    #endif
>>    #if IS_ENABLED(CONFIG_IPV6)
>>    	struct sockaddr_in6 sadd;
>>    	int proto;
>> +
>> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
>> +		family = PF_INET;
>>    #endif /* CONFIG_IPV6 */
>>
>> -	switch (sk->sk_family) {
>> +	switch (family) {
>>    	case PF_INET:
>>    #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>>    		/*
>> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    		 */
>>    		netlbl_secattr_init(&secattr);
>>
>> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
>> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>>    		if (rc == 0)
>>    			skp = smack_from_secattr(&secattr, ssp);
>>    		else
>> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    #endif
>>    #ifdef CONFIG_AUDIT
>>    		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
>> -		ad.a.u.net->family = sk->sk_family;
>> +		ad.a.u.net->family = family;
>>    		ad.a.u.net->netif = skb->skb_iif;
>>    		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>>    #endif
>> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>> *sk, struct sk_buff *skb)
>>    		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>>    					MAY_WRITE, rc);
>>    		if (rc != 0)
>> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
>> +			netlbl_skbuff_err(skb, family, rc, 0);
>>    		break;
>>    #if IS_ENABLED(CONFIG_IPV6)
>>    	case PF_INET6:
> 
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> 
> 
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Casey Schaufler July 17, 2018, 3:01 p.m. UTC | #7
On 7/17/2018 3:28 AM, Piotr Sawicki wrote:
>
> On 07/17/2018 01:33 AM, Casey Schaufler wrote:
>> On 7/10/2018 12:05 AM, Piotr Sawicki wrote:
>>> A socket which has sk_family set to PF_INET6 is able to receive not
>>> only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).
>>>
>>> Prior to this patch, the smk_skb_to_addr_ipv6() could have been
>>> called for socket buffers containing IPv4 packets, in result such
>>> traffic was allowed.
>>>
>>> Signed-off-by: Piotr Sawicki <p.sawicki2@partner.samsung.com>
>> Acked-by: Casey Schaufler <casey@schaufler-ca.com
>>
>> I have added this to git://github.com/cschaufler/next-smack#smack-for-4.19
>> after doing a little whitespace clean-up and removal of unnecessary braces.
> I see that the wrong version of the patch was applied. It should be a 
> version taken from the email titled "[PATCH RFC] Smack: Fix handling of 
> IPv4 traffic received by PF_INET6 sockets" (10th of July 2018). The 
> family variable should be used also in netlbl_skbuff_getattr(), 
> netlbl_skbuff_err and in audit structure.

Please resend the correct version with a "v2". Thank you.

>
>
>>> ---
>>>    security/smack/smack_lsm.c | 12 ++++++++----
>>>    1 file changed, 8 insertions(+), 4 deletions(-)
>>>
>>> diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
>>> index 19de675..1315de4 100644
>>> --- a/security/smack/smack_lsm.c
>>> +++ b/security/smack/smack_lsm.c
>>> @@ -3924,15 +3924,19 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    	struct smack_known *skp = NULL;
>>>    	int rc = 0;
>>>    	struct smk_audit_info ad;
>>> +	u16 family = sk->sk_family;
>>>    #ifdef CONFIG_AUDIT
>>>    	struct lsm_network_audit net;
>>>    #endif
>>>    #if IS_ENABLED(CONFIG_IPV6)
>>>    	struct sockaddr_in6 sadd;
>>>    	int proto;
>>> +
>>> +	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
>>> +		family = PF_INET;
>>>    #endif /* CONFIG_IPV6 */
>>>
>>> -	switch (sk->sk_family) {
>>> +	switch (family) {
>>>    	case PF_INET:
>>>    #ifdef CONFIG_SECURITY_SMACK_NETFILTER
>>>    		/*
>>> @@ -3950,7 +3954,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    		 */
>>>    		netlbl_secattr_init(&secattr);
>>>
>>> -		rc = netlbl_skbuff_getattr(skb, sk->sk_family, &secattr);
>>> +		rc = netlbl_skbuff_getattr(skb, family, &secattr);
>>>    		if (rc == 0)
>>>    			skp = smack_from_secattr(&secattr, ssp);
>>>    		else
>>> @@ -3963,7 +3967,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    #endif
>>>    #ifdef CONFIG_AUDIT
>>>    		smk_ad_init_net(&ad, __func__, LSM_AUDIT_DATA_NET, &net);
>>> -		ad.a.u.net->family = sk->sk_family;
>>> +		ad.a.u.net->family = family;
>>>    		ad.a.u.net->netif = skb->skb_iif;
>>>    		ipv4_skb_to_auditdata(skb, &ad.a, NULL);
>>>    #endif
>>> @@ -3977,7 +3981,7 @@ static int smack_socket_sock_rcv_skb(struct sock
>>> *sk, struct sk_buff *skb)
>>>    		rc = smk_bu_note("IPv4 delivery", skp, ssp->smk_in,
>>>    					MAY_WRITE, rc);
>>>    		if (rc != 0)
>>> -			netlbl_skbuff_err(skb, sk->sk_family, rc, 0);
>>> +			netlbl_skbuff_err(skb, family, rc, 0);
>>>    		break;
>>>    #if IS_ENABLED(CONFIG_IPV6)
>>>    	case PF_INET6:
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>>
>>

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diff mbox

Patch

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index 19de675..1315de4 100644
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -3924,15 +3924,19 @@  static int smack_socket_sock_rcv_skb(struct sock 
*sk, struct sk_buff *skb)
  	struct smack_known *skp = NULL;
  	int rc = 0;
  	struct smk_audit_info ad;
+	u16 family = sk->sk_family;
  #ifdef CONFIG_AUDIT
  	struct lsm_network_audit net;
  #endif
  #if IS_ENABLED(CONFIG_IPV6)
  	struct sockaddr_in6 sadd;
  	int proto;
+
+	if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
+		family = PF_INET;
  #endif /* CONFIG_IPV6 */

-	switch (sk->sk_family) {
+	switch (family) {
  	case PF_INET:
  #ifdef CONFIG_SECURITY_SMACK_NETFILTER