Subject: Re: [PATCH] bluetooth: Properly clone LSM attributes to newly created child connections

From: Casey Schaufler <[email-masked]>
Date: Fri, 07 Oct 2011 13:26:38 -0700

On 10/7/2011 12:40 PM, Paul Moore wrote:
> The Bluetooth stack has internal connection handlers for all of the various
> Bluetooth protocols, and unfortunately, they are currently lacking the LSM
> hooks found in the core network stack's connection handlers.  I say
> unfortunately, because this can cause problems for users who have have an
> LSM enabled and are using certain Bluetooth devices.  See one problem
> report below:
>
>  * http://bugzilla.redhat.com/show_bug.cgi?id=741703
>
> In order to keep things simple at this point in time, this patch fixes the
> problem by cloning the parent socket's LSM attributes to the newly created
> child socket.  If we decide we need a more elaborate LSM marking mechanism
> for Bluetooth (I somewhat doubt this) we can always revisit this decision
> in the future.
>
> Reported-by: James M. Cape <[email-masked]>
> Signed-off-by: Paul Moore <[email-masked]>

I haven't tested anything out yet, but it's hard to see
how this would be a problem from the Smack point of view.

> ---
>  net/bluetooth/l2cap_sock.c  |    4 ++++
>  net/bluetooth/rfcomm/sock.c |    3 +++
>  net/bluetooth/sco.c         |    5 ++++-
>  security/security.c         |    1 +
>  4 files changed, 12 insertions(+), 1 deletions(-)
>
> diff --git a/net/bluetooth/l2cap_sock.c b/net/bluetooth/l2cap_sock.c
> index 61f1f62..e829236 100644
> --- a/net/bluetooth/l2cap_sock.c
> +++ b/net/bluetooth/l2cap_sock.c
> @@ -26,6 +26,8 @@
>  
>  /* Bluetooth L2CAP sockets. */
>  
> +#include <linux/security.h>
> +
>  #include <net/bluetooth/bluetooth.h>
>  #include <net/bluetooth/hci_core.h>
>  #include <net/bluetooth/l2cap.h>
> @@ -933,6 +935,8 @@ static void l2cap_sock_init(struct sock *sk, struct sock *parent)
>  		chan->force_reliable = pchan->force_reliable;
>  		chan->flushable = pchan->flushable;
>  		chan->force_active = pchan->force_active;
> +
> +		security_sk_clone(parent, sk);
>  	} else {
>  
>  		switch (sk->sk_type) {
> diff --git a/net/bluetooth/rfcomm/sock.c b/net/bluetooth/rfcomm/sock.c
> index 482722b..5417f61 100644
> --- a/net/bluetooth/rfcomm/sock.c
> +++ b/net/bluetooth/rfcomm/sock.c
> @@ -42,6 +42,7 @@
>  #include <linux/device.h>
>  #include <linux/debugfs.h>
>  #include <linux/seq_file.h>
> +#include <linux/security.h>
>  #include <net/sock.h>
>  
>  #include <asm/system.h>
> @@ -264,6 +265,8 @@ static void rfcomm_sock_init(struct sock *sk, struct sock *parent)
>  
>  		pi->sec_level = rfcomm_pi(parent)->sec_level;
>  		pi->role_switch = rfcomm_pi(parent)->role_switch;
> +
> +		security_sk_clone(parent, sk);
>  	} else {
>  		pi->dlc->defer_setup = 0;
>  
> diff --git a/net/bluetooth/sco.c b/net/bluetooth/sco.c
> index 8270f05..a324b00 100644
> --- a/net/bluetooth/sco.c
> +++ b/net/bluetooth/sco.c
> @@ -41,6 +41,7 @@
>  #include <linux/debugfs.h>
>  #include <linux/seq_file.h>
>  #include <linux/list.h>
> +#include <linux/security.h>
>  #include <net/sock.h>
>  
>  #include <asm/system.h>
> @@ -403,8 +404,10 @@ static void sco_sock_init(struct sock *sk, struct sock *parent)
>  {
>  	BT_DBG("sk %p", sk);
>  
> -	if (parent)
> +	if (parent) {
>  		sk->sk_type = parent->sk_type;
> +		security_sk_clone(parent, sk);
> +	}
>  }
>  
>  static struct proto sco_proto = {
> diff --git a/security/security.c b/security/security.c
> index 0e4fccf..d9e1533 100644
> --- a/security/security.c
> +++ b/security/security.c
> @@ -1097,6 +1097,7 @@ void security_sk_clone(const struct sock *sk, struct sock *newsk)
>  {
>  	security_ops->sk_clone_security(sk, newsk);
>  }
> +EXPORT_SYMBOL(security_sk_clone);
>  
>  void security_sk_classify_flow(struct sock *sk, struct flowi *fl)
>  {
>
> --
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