[PATCH v2] selinux: vsock: Set SID for socket returned by accept()

[PATCH v2] selinux: vsock: Set SID for socket returned by accept()

[David Brazdil]

For AF_VSOCK, accept() currently returns sockets that are unlabelled.
Other socket families derive the child's SID from the SID of the parent
and the SID of the incoming packet. This is typically done as the
connected socket is placed in the queue that accept() removes from.

Reuse the existing 'security_sk_clone' hook to copy the SID from the
parent (server) socket to the child. There is no packet SID in this
case.

Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Signed-off-by: David Brazdil <dbrazdil@google.com>
---
Tested on Android AOSP and Fedora 33 with v5.12-rc3.
Unit test is available here:
  https://github.com/SELinuxProject/selinux-testsuite/pull/75

Changes since v1:
  * reuse security_sk_clone instead of adding a new hook

 net/vmw_vsock/af_vsock.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 5546710d8ac1..bc7fb9bf3351 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -755,6 +755,7 @@ static struct sock *__vsock_create(struct net *net,
 		vsk->buffer_size = psk->buffer_size;
 		vsk->buffer_min_size = psk->buffer_min_size;
 		vsk->buffer_max_size = psk->buffer_max_size;
+		security_sk_clone(parent, sk);
 	} else {
 		vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
 		vsk->owner = get_current_cred();
-- 
2.31.0.rc2.261.g7f71774620-goog

Re: [PATCH v2] selinux: vsock: Set SID for socket returned by accept()

[David Brazdil]

On Fri, Mar 19, 2021 at 01:05:41PM +0000, David Brazdil wrote:
> For AF_VSOCK, accept() currently returns sockets that are unlabelled.
> Other socket families derive the child's SID from the SID of the parent
> and the SID of the incoming packet. This is typically done as the
> connected socket is placed in the queue that accept() removes from.
> 
> Reuse the existing 'security_sk_clone' hook to copy the SID from the
> parent (server) socket to the child. There is no packet SID in this
> case.
> 
> Fixes: d021c344051a ("VSOCK: Introduce VM Sockets")
Cc: <stable@vger.kernel.org>
> Signed-off-by: David Brazdil <dbrazdil@google.com>
> ---
> Tested on Android AOSP and Fedora 33 with v5.12-rc3.
> Unit test is available here:
>   https://github.com/SELinuxProject/selinux-testsuite/pull/75
> 
> Changes since v1:
>   * reuse security_sk_clone instead of adding a new hook
> 
>  net/vmw_vsock/af_vsock.c | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
> index 5546710d8ac1..bc7fb9bf3351 100644
> --- a/net/vmw_vsock/af_vsock.c
> +++ b/net/vmw_vsock/af_vsock.c
> @@ -755,6 +755,7 @@ static struct sock *__vsock_create(struct net *net,
>  		vsk->buffer_size = psk->buffer_size;
>  		vsk->buffer_min_size = psk->buffer_min_size;
>  		vsk->buffer_max_size = psk->buffer_max_size;
> +		security_sk_clone(parent, sk);
>  	} else {
>  		vsk->trusted = ns_capable_noaudit(&init_user_ns, CAP_NET_ADMIN);
>  		vsk->owner = get_current_cred();
> -- 
> 2.31.0.rc2.261.g7f71774620-goog
> 

Re: [PATCH v2] selinux: vsock: Set SID for socket returned by accept()

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Fri, 19 Mar 2021 13:05:41 +0000 you wrote:
> For AF_VSOCK, accept() currently returns sockets that are unlabelled.
> Other socket families derive the child's SID from the SID of the parent
> and the SID of the incoming packet. This is typically done as the
> connected socket is placed in the queue that accept() removes from.
> 
> Reuse the existing 'security_sk_clone' hook to copy the SID from the
> parent (server) socket to the child. There is no packet SID in this
> case.
> 
> [...]

Here is the summary with links:
  - [v2] selinux: vsock: Set SID for socket returned by accept()
    https://git.kernel.org/netdev/net/c/1f935e8e72ec

You are awesome, thank you!
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