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 <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx> 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 <herbert@xxxxxxxxxxxxxxxxxxx> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt