Re: [PATCH v22 16/23] LSM: security_secid_to_secctx in netlink netfilter

Hi Casey, On Wed, Nov 04, 2020 at 04:49:17PM -0800, Casey Schaufler wrote: > Change netlink netfilter interfaces to use lsmcontext > pointers, and remove scaffolding. > > Reviewed-by: Kees Cook <keescook(a)chromium.org&gt; > Reviewed-by: John Johansen <john.johansen(a)canonical.com&gt; > Acked-by: Stephen Smalley <sds(a)tycho.nsa.gov&gt; > Signed-off-by: Casey Schaufler <casey(a)schaufler-ca.com&gt; > Cc: netdev(a)vger.kernel.org > Cc: netfilter-devel(a)vger.kernel.org You can carry this tag in your follow up patches. Acked-by: Pablo Neira Ayuso <pablo(a)netfilter.org&gt;

Thanks. > --- > net/netfilter/nfnetlink_queue.c | 37 +++++++++++++-------------------- > 1 file changed, 14 insertions(+), 23 deletions(-) > > diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c > index 84be5a49a157..0d8b83d84422 100644 > --- a/net/netfilter/nfnetlink_queue.c > +++ b/net/netfilter/nfnetlink_queue.c > @@ -301,15 +301,13 @@ static int nfqnl_put_sk_uidgid(struct sk_buff *skb, struct sock *sk) > return -1; > } > > -static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) > +static void nfqnl_get_sk_secctx(struct sk_buff *skb, struct lsmcontext *context) > { > - u32 seclen = 0; > #if IS_ENABLED(CONFIG_NETWORK_SECMARK) > struct lsmblob blob; > - struct lsmcontext context = { }; > > if (!skb || !sk_fullsock(skb->sk)) > - return 0; > + return; > > read_lock_bh(&skb->sk->sk_callback_lock); > > @@ -318,14 +316,12 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) > * blob. security_secid_to_secctx() will know which security > * module to use to create the secctx. */ > lsmblob_init(&blob, skb->secmark); > - security_secid_to_secctx(&blob, &context); > - *secdata = context.context; > + security_secid_to_secctx(&blob, context); > } > > read_unlock_bh(&skb->sk->sk_callback_lock); > - seclen = context.len; > #endif > - return seclen; > + return; > } > > static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) > @@ -398,12 +394,10 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > struct net_device *indev; > struct net_device *outdev; > struct nf_conn *ct = NULL; > + struct lsmcontext context = { }; > enum ip_conntrack_info ctinfo; > struct nfnl_ct_hook *nfnl_ct; > bool csum_verify; > - struct lsmcontext scaff; /* scaffolding */ > - char *secdata = NULL; > - u32 seclen = 0; > > size = nlmsg_total_size(sizeof(struct nfgenmsg)) > + nla_total_size(sizeof(struct nfqnl_msg_packet_hdr)) > @@ -469,9 +463,9 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > } > > if ((queue->flags & NFQA_CFG_F_SECCTX) && entskb->sk) { > - seclen = nfqnl_get_sk_secctx(entskb, &secdata); > - if (seclen) > - size += nla_total_size(seclen); > + nfqnl_get_sk_secctx(entskb, &context); > + if (context.len) > + size += nla_total_size(context.len); > } > > skb = alloc_skb(size, GFP_ATOMIC); > @@ -604,7 +598,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > nfqnl_put_sk_uidgid(skb, entskb->sk) < 0) > goto nla_put_failure; > > - if (seclen && nla_put(skb, NFQA_SECCTX, seclen, secdata)) > + if (context.len && > + nla_put(skb, NFQA_SECCTX, context.len, context.context)) > goto nla_put_failure; > > if (ct && nfnl_ct->build(skb, ct, ctinfo, NFQA_CT, NFQA_CT_INFO) < 0) > @@ -632,10 +627,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > } > > nlh->nlmsg_len = skb->len; > - if (seclen) { > - lsmcontext_init(&scaff, secdata, seclen, 0); > - security_release_secctx(&scaff); > - } > + if (context.len) > + security_release_secctx(&context); > return skb; > > nla_put_failure: > @@ -643,10 +636,8 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > kfree_skb(skb); > net_err_ratelimited("nf_queue: error creating packet message\n"); > nlmsg_failure: > - if (seclen) { > - lsmcontext_init(&scaff, secdata, seclen, 0); > - security_release_secctx(&scaff); > - } > + if (context.len) > + security_release_secctx(&context); > return NULL; > } > > -- > 2.24.1 >