Re: [GIT] Networking

[Herbert Xu]

On Tue, Jul 11, 2017 at 01:31:14PM -0700, David Miller wrote:
>
> Acked-by: David S. Miller 
> 
> Looks good, is this going via my tree or your's?

I'll push it along.  Thanks.
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt

Re: [GIT] Networking

[David Miller]

From: Herbert Xu 
Date: Mon, 10 Jul 2017 22:00:48 +0800

> crypto: af_alg - Avoid sock_graft call warning
> 
> The newly added sock_graft warning triggers in af_alg_accept.
> It's harmless as we're essentially doing sock->sk = sock->sk.
> 
> The sock_graft call is actually redundant because all the work
> it does is subsumed by sock_init_data.  However, it was added
> to placate SELinux as it uses it to initialise its internal state.
> 
> This patch avoisd the warning by making the SELinux call directly.
> 
> Reported-by: Linus Torvalds 
> Signed-off-by: Herbert Xu 

Acked-by: David S. Miller 

Looks good, is this going via my tree or your's?

Re: [GIT] Networking

[Herbert Xu]

On Mon, Jul 10, 2017 at 08:10:02AM -0400, Sowmini Varadhan wrote:
>
> The reason that the WARN_ON is triggered is that af_alg_accept() calls
> sock_init_data() which does 
> 
>2636 if (sock) {
> :
>2639 sock->sk=   sk;

Oh yes.  This started out with just sock_init_data which would
not have triggered your warning.  Then someone came along and
added sock_graft which basically duplicates work already done in
sock_init_data.

In fact the reason they wanted sock_graft was purely to call
security_sock_graft to initialise some SELinux state.  So we
could avoid your warning by calling that directly.

---8<---
crypto: af_alg - Avoid sock_graft call warning

The newly added sock_graft warning triggers in af_alg_accept.
It's harmless as we're essentially doing sock->sk = sock->sk.

The sock_graft call is actually redundant because all the work
it does is subsumed by sock_init_data.  However, it was added
to placate SELinux as it uses it to initialise its internal state.

This patch avoisd the warning by making the SELinux call directly.

Reported-by: Linus Torvalds 
Signed-off-by: Herbert Xu 

diff --git a/crypto/af_alg.c b/crypto/af_alg.c
index 3556d8e..92a3d54 100644
--- a/crypto/af_alg.c
+++ b/crypto/af_alg.c
@@ -287,7 +287,7 @@ int af_alg_accept(struct sock *sk, struct socket *newsock, 
bool kern)
goto unlock;
 
sock_init_data(newsock, sk2);
-   sock_graft(sk2, newsock);
+   security_sock_graft(sk2, newsock);
security_sk_clone(sk, sk2);
 
err = type->accept(ask->private, sk2);
-- 
Email: Herbert Xu 
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt