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Thu, 21 Nov 2019 14:01:35 -0500 Received: from static-50-53-33-191.bvtn.or.frontiernet.net ([50.53.33.191] helo=[192.168.192.153]) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1iXrhs-0005Be-Du; Thu, 21 Nov 2019 19:01:32 +0000 Subject: Re: [PATCH v11 18/25] LSM: security_secid_to_secctx in netlink netfilter To: Casey Schaufler , casey.schaufler@intel.com, jmorris@namei.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org Cc: keescook@chromium.org, penguin-kernel@i-love.sakura.ne.jp, paul@paul-moore.com, sds@tycho.nsa.gov References: <20191113182506.2580-1-casey@schaufler-ca.com> <20191113182506.2580-2-casey@schaufler-ca.com> From: John Johansen Openpgp: preference=signencrypt Autocrypt: addr=john.johansen@canonical.com; prefer-encrypt=mutual; keydata= xsFNBE5mrPoBEADAk19PsgVgBKkImmR2isPQ6o7KJhTTKjJdwVbkWSnNn+o6Up5knKP1f49E BQlceWg1yp/NwbR8ad+eSEO/uma/K+PqWvBptKC9SWD97FG4uB4/caomLEU97sLQMtnvGWdx rxVRGM4anzWYMgzz5TZmIiVTZ43Ou5VpaS1Vz1ZSxP3h/xKNZr/TcW5WQai8u3PWVnbkjhSZ PHv1BghN69qxEPomrJBm1gmtx3ZiVmFXluwTmTgJOkpFol7nbJ0ilnYHrA7SX3CtR1upeUpM a/WIanVO96WdTjHHIa43fbhmQube4txS3FcQLOJVqQsx6lE9B7qAppm9hQ10qPWwdfPy/+0W 6AWtNu5ASiGVCInWzl2HBqYd/Zll93zUq+NIoCn8sDAM9iH+wtaGDcJywIGIn+edKNtK72AM gChTg/j1ZoWH6ZeWPjuUfubVzZto1FMoGJ/SF4MmdQG1iQNtf4sFZbEgXuy9cGi2bomF0zvy BJSANpxlKNBDYKzN6Kz09HUAkjlFMNgomL/cjqgABtAx59L+dVIZfaF281pIcUZzwvh5+JoG eOW5uBSMbE7L38nszooykIJ5XrAchkJxNfz7k+FnQeKEkNzEd2LWc3QF4BQZYRT6PHHga3Rg ykW5+1wTMqJILdmtaPbXrF3FvnV0LRPcv4xKx7B3fGm7ygdoowARAQABzR1Kb2huIEpvaGFu c2VuIDxqb2huQGpqbXgubmV0PsLBegQTAQoAJAIbAwULCQgHAwUVCgkICwUWAgMBAAIeAQIX gAUCTo0YVwIZAQAKCRAFLzZwGNXD2LxJD/9TJZCpwlncTgYeraEMeDfkWv8c1IsM1j0AmE4V tL+fE780ZVP9gkjgkdYSxt7ecETPTKMaZSisrl1RwqU0oogXdXQSpxrGH01icu/2n0jcYSqY KggPxy78BGs2LZq4XPfJTZmHZGnXGq/eDr/mSnj0aavBJmMZ6jbiPz6yHtBYPZ9fdo8btczw P41YeWoIu26/8II6f0Xm3VC5oAa8v7Rd+RWZa8TMwlhzHExxel3jtI7IzzOsnmE9/8Dm0ARD 5iTLCXwR1cwI/J9BF/S1Xv8PN1huT3ItCNdatgp8zqoJkgPVjmvyL64Q3fEkYbfHOWsaba9/ kAVtBNz9RTFh7IHDfECVaToujBd7BtPqr+qIjWFadJD3I5eLCVJvVrrolrCATlFtN3YkQs6J n1AiIVIU3bHR8Gjevgz5Ll6SCGHgRrkyRpnSYaU/uLgn37N6AYxi/QAL+by3CyEFLjzWAEvy Q8bq3Iucn7JEbhS/J//dUqLoeUf8tsGi00zmrITZYeFYARhQMtsfizIrVDtz1iPf/ZMp5gRB niyjpXn131cm3M3gv6HrQsAGnn8AJru8GDi5XJYIco/1+x/qEiN2nClaAOpbhzN2eUvPDY5W 0q3bA/Zp2mfG52vbRI+tQ0Br1Hd/vsntUHO903mMZep2NzN3BZ5qEvPvG4rW5Zq2DpybWc7B TQROZqz6ARAAoqw6kkBhWyM1fvgamAVjeZ6nKEfnRWbkC94L1EsJLup3Wb2X0ABNOHSkbSD4 pAuC2tKF/EGBt5CP7QdVKRGcQzAd6b2c1Idy9RLw6w4gi+nn/d1Pm1kkYhkSi5zWaIg0m5RQ Uk+El8zkf5tcE/1N0Z5OK2JhjwFu5bX0a0l4cFGWVQEciVMDKRtxMjEtk3SxFalm6ZdQ2pp2 822clnq4zZ9mWu1d2waxiz+b5Ia4weDYa7n41URcBEUbJAgnicJkJtCTwyIxIW2KnVyOrjvk QzIBvaP0FdP2vvZoPMdlCIzOlIkPLgxE0IWueTXeBJhNs01pb8bLqmTIMlu4LvBELA/veiaj j5s8y542H/aHsfBf4MQUhHxO/BZV7h06KSUfIaY7OgAgKuGNB3UiaIUS5+a9gnEOQLDxKRy/ a7Q1v9S+Nvx+7j8iH3jkQJhxT6ZBhZGRx0gkH3T+F0nNDm5NaJUsaswgJrqFZkUGd2Mrm1qn KwXiAt8SIcENdq33R0KKKRC80Xgwj8Jn30vXLSG+NO1GH0UMcAxMwy/pvk6LU5JGjZR73J5U LVhH4MLbDggD3mPaiG8+fotTrJUPqqhg9hyUEPpYG7sqt74Xn79+CEZcjLHzyl6vAFE2W0kx lLtQtUZUHO36afFv8qGpO3ZqPvjBUuatXF6tvUQCwf3H6XMAEQEAAcLBXwQYAQoACQUCTmas +gIbDAAKCRAFLzZwGNXD2D/XD/0ddM/4ai1b+Tl1jznKajX3kG+MeEYeI4f40vco3rOLrnRG FOcbyyfVF69MKepie4OwoI1jcTU0ADecnbWnDNHpr0SczxBMro3bnrLhsmvjunTYIvssBZtB 4aVJjuLILPUlnhFqa7fbVq0ZQjbiV/rt2jBENdm9pbJZ6GjnpYIcAbPCCa/ffL4/SQRSYHXo hGiiS4y5jBTmK5ltfewLOw02fkexH+IJFrrGBXDSg6n2Sgxnn++NF34fXcm9piaw3mKsICm+ 0hdNh4afGZ6IWV8PG2teooVDp4dYih++xX/XS8zBCc1O9w4nzlP2gKzlqSWbhiWpifRJBFa4 WtAeJTdXYd37j/BI4RWWhnyw7aAPNGj33ytGHNUf6Ro2/jtj4tF1y/QFXqjJG/wGjpdtRfbt UjqLHIsvfPNNJq/958p74ndACidlWSHzj+Op26KpbFnmwNO0psiUsnhvHFwPO/vAbl3RsR5+ 0Ro+hvs2cEmQuv9r/bDlCfpzp2t3cK+rhxUqisOx8DZfz1BnkaoCRFbvvvk+7L/fomPntGPk qJciYE8TGHkZw1hOku+4OoM2GB5nEDlj+2TF/jLQ+EipX9PkPJYvxfRlC6dK8PKKfX9KdfmA IcgHfnV1jSn+8yH2djBPtKiqW0J69aIsyx7iV/03paPCjJh7Xq9vAzydN5U/UA== Organization: Canonical Message-ID: Date: Thu, 21 Nov 2019 11:01:25 -0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191113182506.2580-2-casey@schaufler-ca.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: On 11/13/19 10:24 AM, Casey Schaufler wrote: > Change netlink netfilter interfaces to use lsmcontext > pointers, and remove scaffolding. > > Reviewed-by: Kees Cook > Reviewed-by: John Johansen > Signed-off-by: Casey Schaufler > cc: netdev@vger.kernel.org Acked-by: John Johansen > --- > net/netfilter/nfnetlink_queue.c | 32 +++++++++++++------------------- > 1 file changed, 13 insertions(+), 19 deletions(-) > > diff --git a/net/netfilter/nfnetlink_queue.c b/net/netfilter/nfnetlink_queue.c > index 2d6668fd026c..a1296453d8f2 100644 > --- a/net/netfilter/nfnetlink_queue.c > +++ b/net/netfilter/nfnetlink_queue.c > @@ -301,12 +301,10 @@ 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 u32 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; > @@ -314,15 +312,16 @@ static u32 nfqnl_get_sk_secctx(struct sk_buff *skb, char **secdata) > read_lock_bh(&skb->sk->sk_callback_lock); > > if (skb->secmark) { > + /* Any LSM might be looking for the secmark */ > 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; > + return context->len; > +#else > + return 0; > #endif > - return seclen; > } > > static u32 nfqnl_get_bridge_size(struct nf_queue_entry *entry) > @@ -398,8 +397,7 @@ nfqnl_build_packet_message(struct net *net, struct nfqnl_instance *queue, > enum ip_conntrack_info uninitialized_var(ctinfo); > struct nfnl_ct_hook *nfnl_ct; > bool csum_verify; > - struct lsmcontext scaff; /* scaffolding */ > - char *secdata = NULL; > + struct lsmcontext context = { }; > u32 seclen = 0; > > size = nlmsg_total_size(sizeof(struct nfgenmsg)) > @@ -466,7 +464,7 @@ 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); > + seclen = nfqnl_get_sk_secctx(entskb, &context); > if (seclen) > size += nla_total_size(seclen); > } > @@ -601,7 +599,7 @@ 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 (seclen && 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) > @@ -629,10 +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 (seclen) > + security_release_secctx(&context); > return skb; > > nla_put_failure: > @@ -640,10 +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 (seclen) > + security_release_secctx(&context); > return NULL; > } > >