apparmor: Allow filtering based on secmark policy (ab9f2115) · Commits · e / devices / android_kernel_fairphone_FP5

security/apparmor/lsm.c

+111 −1

Original line number	Diff line number	Diff line
		@@ -23,6 +23,8 @@
		#include <linux/sysctl.h>
		#include <linux/audit.h>
		#include <linux/user_namespace.h>
		#include <linux/netfilter_ipv4.h>
		#include <linux/netfilter_ipv6.h>
		#include <net/sock.h>

		#include "include/apparmor.h"
		@@ -1030,7 +1032,13 @@ static int apparmor_socket_shutdown(struct socket *sock, int how)
		*/
		static int apparmor_socket_sock_rcv_skb(struct sock sk, struct sk_buff skb)
		{
		struct aa_sk_ctx *ctx = SK_CTX(sk);

		if (!skb->secmark)
		return 0;

		return apparmor_secmark_check(ctx->label, OP_RECVMSG, AA_MAY_RECEIVE,
		skb->secmark, sk);
		}


		@@ -1126,6 +1134,18 @@ static void apparmor_sock_graft(struct sock sk, struct socket parent)
		ctx->label = aa_get_current_label();
		}

		static int apparmor_inet_conn_request(struct sock sk, struct sk_buff skb,
		struct request_sock *req)
		{
		struct aa_sk_ctx *ctx = SK_CTX(sk);

		if (!skb->secmark)
		return 0;

		return apparmor_secmark_check(ctx->label, OP_CONNECT, AA_MAY_CONNECT,
		skb->secmark, sk);
		}

		static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
		LSM_HOOK_INIT(ptrace_access_check, apparmor_ptrace_access_check),
		LSM_HOOK_INIT(ptrace_traceme, apparmor_ptrace_traceme),
		@@ -1183,6 +1203,7 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
		LSM_HOOK_INIT(socket_getpeersec_dgram,
		apparmor_socket_getpeersec_dgram),
		LSM_HOOK_INIT(sock_graft, apparmor_sock_graft),
		LSM_HOOK_INIT(inet_conn_request, apparmor_inet_conn_request),

		LSM_HOOK_INIT(cred_alloc_blank, apparmor_cred_alloc_blank),
		LSM_HOOK_INIT(cred_free, apparmor_cred_free),
		@@ -1538,6 +1559,95 @@ static inline int apparmor_init_sysctl(void)
		}
		#endif /* CONFIG_SYSCTL */

		static unsigned int apparmor_ip_postroute(void *priv,
		struct sk_buff *skb,
		const struct nf_hook_state *state)
		{
		struct aa_sk_ctx *ctx;
		struct sock *sk;

		if (!skb->secmark)
		return NF_ACCEPT;

		sk = skb_to_full_sk(skb);
		if (sk == NULL)
		return NF_ACCEPT;

		ctx = SK_CTX(sk);
		if (!apparmor_secmark_check(ctx->label, OP_SENDMSG, AA_MAY_SEND,
		skb->secmark, sk))
		return NF_ACCEPT;

		return NF_DROP_ERR(-ECONNREFUSED);

		}

		static unsigned int apparmor_ipv4_postroute(void *priv,
		struct sk_buff *skb,
		const struct nf_hook_state *state)
		{
		return apparmor_ip_postroute(priv, skb, state);
		}

		static unsigned int apparmor_ipv6_postroute(void *priv,
		struct sk_buff *skb,
		const struct nf_hook_state *state)
		{
		return apparmor_ip_postroute(priv, skb, state);
		}

		static const struct nf_hook_ops apparmor_nf_ops[] = {
		{
		.hook = apparmor_ipv4_postroute,
		.pf = NFPROTO_IPV4,
		.hooknum = NF_INET_POST_ROUTING,
		.priority = NF_IP_PRI_SELINUX_FIRST,
		},
		#if IS_ENABLED(CONFIG_IPV6)
		{
		.hook = apparmor_ipv6_postroute,
		.pf = NFPROTO_IPV6,
		.hooknum = NF_INET_POST_ROUTING,
		.priority = NF_IP6_PRI_SELINUX_FIRST,
		},
		#endif
		};

		static int __net_init apparmor_nf_register(struct net *net)
		{
		int ret;

		ret = nf_register_net_hooks(net, apparmor_nf_ops,
		ARRAY_SIZE(apparmor_nf_ops));
		return ret;
		}

		static void __net_exit apparmor_nf_unregister(struct net *net)
		{
		nf_unregister_net_hooks(net, apparmor_nf_ops,
		ARRAY_SIZE(apparmor_nf_ops));
		}

		static struct pernet_operations apparmor_net_ops = {
		.init = apparmor_nf_register,
		.exit = apparmor_nf_unregister,
		};

		static int __init apparmor_nf_ip_init(void)
		{
		int err;

		if (!apparmor_enabled)
		return 0;

		err = register_pernet_subsys(&apparmor_net_ops);
		if (err)
		panic("Apparmor: register_pernet_subsys: error %d\n", err);

		return 0;
		}
		__initcall(apparmor_nf_ip_init);

		static int __init apparmor_init(void)
		{
		int error;

security/apparmor/net.c

+66 −0

Original line number	Diff line number	Diff line
		@@ -18,6 +18,7 @@
		#include "include/label.h"
		#include "include/net.h"
		#include "include/policy.h"
		#include "include/secid.h"

		#include "net_names.h"

		@@ -188,3 +189,68 @@ int aa_sock_file_perm(struct aa_label label, const char op, u32 request,

		return aa_label_sk_perm(label, op, request, sock->sk);
		}

		static int apparmor_secmark_init(struct aa_secmark *secmark)
		{
		struct aa_label *label;

		if (secmark->label[0] == '*') {
		secmark->secid = AA_SECID_WILDCARD;
		return 0;
		}

		label = aa_label_strn_parse(&root_ns->unconfined->label,
		secmark->label, strlen(secmark->label),
		GFP_ATOMIC, false, false);

		if (IS_ERR(label))
		return PTR_ERR(label);

		secmark->secid = label->secid;

		return 0;
		}

		static int aa_secmark_perm(struct aa_profile *profile, u32 request, u32 secid,
		struct common_audit_data sa, struct sock sk)
		{
		int i, ret;
		struct aa_perms perms = { };

		if (profile->secmark_count == 0)
		return 0;

		for (i = 0; i < profile->secmark_count; i++) {
		if (!profile->secmark[i].secid) {
		ret = apparmor_secmark_init(&profile->secmark[i]);
		if (ret)
		return ret;
		}

		if (profile->secmark[i].secid == secid \|\|
		profile->secmark[i].secid == AA_SECID_WILDCARD) {
		if (profile->secmark[i].deny)
		perms.deny = ALL_PERMS_MASK;
		else
		perms.allow = ALL_PERMS_MASK;

		if (profile->secmark[i].audit)
		perms.audit = ALL_PERMS_MASK;
		}
		}

		aa_apply_modes_to_perms(profile, &perms);

		return aa_check_perms(profile, &perms, request, sa, audit_net_cb);
		}

		int apparmor_secmark_check(struct aa_label label, char op, u32 request,
		u32 secid, struct sock *sk)
		{
		struct aa_profile *profile;
		DEFINE_AUDIT_SK(sa, op, sk);

		return fn_for_each_confined(label, profile,
		aa_secmark_perm(profile, request, secid,
		&sa, sk));
		}