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

Hi Paul,

I'll post a v2 shortly but will address your comments here.

quoted

 include/linux/lsm_hooks.h     |  7 +++++++
 include/linux/security.h      |  5 +++++
 net/vmw_vsock/af_vsock.c      |  1 +
 security/security.c           |  5 +++++
 security/selinux/hooks.c      | 10 ++++++++++
 6 files changed, 29 insertions(+)

Additional comments below, but I think it would be a good idea for you
to test your patches on a more traditional Linux distribution as well
as Android.

No problem, I was going to add a test case into selinux-testsuite
anyway. Done now (link in v2) and tested on Fedora 33 with v5.12-rc3.

quoted

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 5546710d8ac1..a9bf3b90cb2f 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_vsock_sk_clone(parent, sk);

Did you try calling the existing security_sk_clone() hook here?  I
would be curious to hear why it doesn't work in this case.

Feel free to educate me on AF_VSOCK, it's entirely possible I'm
misunderstanding something here :)

No, you're completely right. security_sk_clone does what's needed here.
Adding a new hook was me trying to mimic other socket families going via
selinux_conn_sid. Happy to reuse the existing hook - makes this a nice
oneliner. :)

Please note that I'm marking v2 with 'Fixes' for backporting. This does
feel to me like a bug, an integration that was never considered. Please
shout if you disagree.

-David