path: root/0012-apparmor-add-base-infastructure-for-socket-mediation.patch

From 853cbdfb6924857a2ee2a1cd5b9fa494f8e7efa2 Mon Sep 17 00:00:00 2001
From: John Johansen <john.johansen@canonical.com>
Date: Tue, 18 Jul 2017 23:18:33 -0700
Subject: [PATCH 12/17] apparmor: add base infastructure for socket mediation

Provide a basic mediation of sockets. This is not a full net mediation
but just whether a spcific family of socket can be used by an
application, along with setting up some basic infrastructure for
network mediation to follow.

the user space rule hav the basic form of
  NETWORK RULE = [ QUALIFIERS ] 'network' [ DOMAIN ]
                 [ TYPE | PROTOCOL ]

  DOMAIN = ( 'inet' | 'ax25' | 'ipx' | 'appletalk' | 'netrom' |
             'bridge' | 'atmpvc' | 'x25' | 'inet6' | 'rose' |
	     'netbeui' | 'security' | 'key' | 'packet' | 'ash' |
	     'econet' | 'atmsvc' | 'sna' | 'irda' | 'pppox' |
	     'wanpipe' | 'bluetooth' | 'netlink' | 'unix' | 'rds' |
	     'llc' | 'can' | 'tipc' | 'iucv' | 'rxrpc' | 'isdn' |
	     'phonet' | 'ieee802154' | 'caif' | 'alg' | 'nfc' |
	     'vsock' | 'mpls' | 'ib' | 'kcm' ) ','

  TYPE = ( 'stream' | 'dgram' | 'seqpacket' |  'rdm' | 'raw' |
           'packet' )

  PROTOCOL = ( 'tcp' | 'udp' | 'icmp' )

eg.
  network,
  network inet,

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Seth Arnold <seth.arnold@canonical.com>
(cherry picked from commit 56387cbe3f287034ee6959cb9e8f419889e38bd9)
---
 security/apparmor/.gitignore       |   1 +
 security/apparmor/Makefile         |  43 ++++-
 security/apparmor/apparmorfs.c     |   1 +
 security/apparmor/file.c           |  30 +++
 security/apparmor/include/audit.h  |  26 ++-
 security/apparmor/include/net.h    | 114 +++++++++++
 security/apparmor/include/perms.h  |   5 +-
 security/apparmor/include/policy.h |  13 ++
 security/apparmor/lib.c            |   5 +-
 security/apparmor/lsm.c            | 387 +++++++++++++++++++++++++++++++++++++
 security/apparmor/net.c            | 184 ++++++++++++++++++
 security/apparmor/policy_unpack.c  |  47 ++++-
 12 files changed, 840 insertions(+), 16 deletions(-)
 create mode 100644 security/apparmor/include/net.h
 create mode 100644 security/apparmor/net.c

diff --git a/security/apparmor/.gitignore b/security/apparmor/.gitignore
index 9cdec70d72b8..d5b291e94264 100644
--- a/security/apparmor/.gitignore
+++ b/security/apparmor/.gitignore
@@ -1,5 +1,6 @@
 #
 # Generated include files
 #
+net_names.h
 capability_names.h
 rlim_names.h
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
index 81a34426d024..dafdd387d42b 100644
--- a/security/apparmor/Makefile
+++ b/security/apparmor/Makefile
@@ -4,11 +4,44 @@ obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o
 
 apparmor-y := apparmorfs.o audit.o capability.o context.o ipc.o lib.o match.o \
               path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \
-              resource.o secid.o file.o policy_ns.o label.o mount.o
+              resource.o secid.o file.o policy_ns.o label.o mount.o net.o
 apparmor-$(CONFIG_SECURITY_APPARMOR_HASH) += crypto.o
 
-clean-files := capability_names.h rlim_names.h
+clean-files := capability_names.h rlim_names.h net_names.h
 
+# Build a lower case string table of address family names
+# Transform lines from
+#    #define AF_LOCAL		1	/* POSIX name for AF_UNIX	*/
+#    #define AF_INET		2	/* Internet IP Protocol 	*/
+# to
+#    [1] = "local",
+#    [2] = "inet",
+#
+# and build the securityfs entries for the mapping.
+# Transforms lines from
+#    #define AF_INET		2	/* Internet IP Protocol 	*/
+# to
+#    #define AA_SFS_AF_MASK "local inet"
+quiet_cmd_make-af = GEN     $@
+cmd_make-af = echo "static const char *address_family_names[] = {" > $@ ;\
+	sed $< >>$@ -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e "/AF_ROUTE/d" -e \
+	 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+	echo "};" >> $@ ;\
+	printf '%s' '\#define AA_SFS_AF_MASK "' >> $@ ;\
+	sed -r -n -e "/AF_MAX/d" -e "/AF_LOCAL/d" -e "/AF_ROUTE/d" -e \
+	 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/\L\1/p'\
+	 $< | tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
+
+# Build a lower case string table of sock type names
+# Transform lines from
+#    SOCK_STREAM	= 1,
+# to
+#    [1] = "stream",
+quiet_cmd_make-sock = GEN     $@
+cmd_make-sock = echo "static const char *sock_type_names[] = {" >> $@ ;\
+	sed $^ >>$@ -r -n \
+	-e 's/^\tSOCK_([A-Z0-9_]+)[\t]+=[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+	echo "};" >> $@
 
 # Build a lower case string table of capability names
 # Transforms lines from
@@ -61,6 +94,7 @@ cmd_make-rlim = echo "static const char *const rlim_names[RLIM_NLIMITS] = {" \
 	    tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
 
 $(obj)/capability.o : $(obj)/capability_names.h
+$(obj)/net.o : $(obj)/net_names.h
 $(obj)/resource.o : $(obj)/rlim_names.h
 $(obj)/capability_names.h : $(srctree)/include/uapi/linux/capability.h \
 			    $(src)/Makefile
@@ -68,3 +102,8 @@ $(obj)/capability_names.h : $(srctree)/include/uapi/linux/capability.h \
 $(obj)/rlim_names.h : $(srctree)/include/uapi/asm-generic/resource.h \
 		      $(src)/Makefile
 	$(call cmd,make-rlim)
+$(obj)/net_names.h : $(srctree)/include/linux/socket.h \
+		     $(srctree)/include/linux/net.h \
+		     $(src)/Makefile
+	$(call cmd,make-af)
+	$(call cmd,make-sock)
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 7acea14c850b..125dad5c3fde 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -2202,6 +2202,7 @@ static struct aa_sfs_entry aa_sfs_entry_features[] = {
 	AA_SFS_DIR("policy",			aa_sfs_entry_policy),
 	AA_SFS_DIR("domain",			aa_sfs_entry_domain),
 	AA_SFS_DIR("file",			aa_sfs_entry_file),
+	AA_SFS_DIR("network",			aa_sfs_entry_network),
 	AA_SFS_DIR("mount",			aa_sfs_entry_mount),
 	AA_SFS_DIR("namespaces",		aa_sfs_entry_ns),
 	AA_SFS_FILE_U64("capability",		VFS_CAP_FLAGS_MASK),
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index 3382518b87fa..db80221891c6 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -21,6 +21,7 @@
 #include "include/context.h"
 #include "include/file.h"
 #include "include/match.h"
+#include "include/net.h"
 #include "include/path.h"
 #include "include/policy.h"
 #include "include/label.h"
@@ -566,6 +567,32 @@ static int __file_path_perm(const char *op, struct aa_label *label,
 	return error;
 }
 
+static int __file_sock_perm(const char *op, struct aa_label *label,
+			    struct aa_label *flabel, struct file *file,
+			    u32 request, u32 denied)
+{
+	struct socket *sock = (struct socket *) file->private_data;
+	int error;
+
+	AA_BUG(!sock);
+
+	/* revalidation due to label out of date. No revocation at this time */
+	if (!denied && aa_label_is_subset(flabel, label))
+		return 0;
+
+	/* TODO: improve to skip profiles cached in flabel */
+	error = aa_sock_file_perm(label, op, request, sock);
+	if (denied) {
+		/* TODO: improve to skip profiles checked above */
+		/* check every profile in file label to is cached */
+		last_error(error, aa_sock_file_perm(flabel, op, request, sock));
+	}
+	if (!error)
+		update_file_ctx(file_ctx(file), label, request);
+
+	return error;
+}
+
 /**
  * aa_file_perm - do permission revalidation check & audit for @file
  * @op: operation being checked
@@ -610,6 +637,9 @@ int aa_file_perm(const char *op, struct aa_label *label, struct file *file,
 		error = __file_path_perm(op, label, flabel, file, request,
 					 denied);
 
+	else if (S_ISSOCK(file_inode(file)->i_mode))
+		error = __file_sock_perm(op, label, flabel, file, request,
+					 denied);
 done:
 	rcu_read_unlock();
 
diff --git a/security/apparmor/include/audit.h b/security/apparmor/include/audit.h
index 620e81169659..ff4316e1068d 100644
--- a/security/apparmor/include/audit.h
+++ b/security/apparmor/include/audit.h
@@ -121,9 +121,15 @@ struct apparmor_audit_data {
 			struct aa_label *peer;
 			union {
 				struct {
-					const char *target;
 					kuid_t ouid;
+					const char *target;
 				} fs;
+				struct {
+					int type, protocol;
+					struct sock *peer_sk;
+					void *addr;
+					int addrlen;
+				} net;
 				struct {
 					int rlim;
 					unsigned long max;
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
new file mode 100644
index 000000000000..140c8efcf364
--- /dev/null
+++ b/security/apparmor/include/net.h
@@ -0,0 +1,114 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor network mediation definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2017 Canonical Ltd.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation, version 2 of the
+ * License.
+ */
+
+#ifndef __AA_NET_H
+#define __AA_NET_H
+
+#include <net/sock.h>
+#include <linux/path.h>
+
+#include "apparmorfs.h"
+#include "label.h"
+#include "perms.h"
+#include "policy.h"
+
+#define AA_MAY_SEND		AA_MAY_WRITE
+#define AA_MAY_RECEIVE		AA_MAY_READ
+
+#define AA_MAY_SHUTDOWN		AA_MAY_DELETE
+
+#define AA_MAY_CONNECT		AA_MAY_OPEN
+#define AA_MAY_ACCEPT		0x00100000
+
+#define AA_MAY_BIND		0x00200000
+#define AA_MAY_LISTEN		0x00400000
+
+#define AA_MAY_SETOPT		0x01000000
+#define AA_MAY_GETOPT		0x02000000
+
+#define NET_PERMS_MASK (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CREATE |    \
+			AA_MAY_SHUTDOWN | AA_MAY_BIND | AA_MAY_LISTEN |	  \
+			AA_MAY_CONNECT | AA_MAY_ACCEPT | AA_MAY_SETATTR | \
+			AA_MAY_GETATTR | AA_MAY_SETOPT | AA_MAY_GETOPT)
+
+#define NET_FS_PERMS (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CREATE |	\
+		      AA_MAY_SHUTDOWN | AA_MAY_CONNECT | AA_MAY_RENAME |\
+		      AA_MAY_SETATTR | AA_MAY_GETATTR | AA_MAY_CHMOD |	\
+		      AA_MAY_CHOWN | AA_MAY_CHGRP | AA_MAY_LOCK |	\
+		      AA_MAY_MPROT)
+
+#define NET_PEER_MASK (AA_MAY_SEND | AA_MAY_RECEIVE | AA_MAY_CONNECT |	\
+		       AA_MAY_ACCEPT)
+struct aa_sk_ctx {
+	struct aa_label *label;
+	struct aa_label *peer;
+	struct path path;
+};
+
+#define SK_CTX(X) ((X)->sk_security)
+#define SOCK_ctx(X) SOCK_INODE(X)->i_security
+#define DEFINE_AUDIT_NET(NAME, OP, SK, F, T, P)				  \
+	struct lsm_network_audit NAME ## _net = { .sk = (SK),		  \
+						  .family = (F)};	  \
+	DEFINE_AUDIT_DATA(NAME,						  \
+			  ((SK) && (F) != AF_UNIX) ? LSM_AUDIT_DATA_NET : \
+						     LSM_AUDIT_DATA_NONE, \
+			  OP);						  \
+	NAME.u.net = &(NAME ## _net);					  \
+	aad(&NAME)->net.type = (T);					  \
+	aad(&NAME)->net.protocol = (P)
+
+#define DEFINE_AUDIT_SK(NAME, OP, SK)					\
+	DEFINE_AUDIT_NET(NAME, OP, SK, (SK)->sk_family, (SK)->sk_type,	\
+			 (SK)->sk_protocol)
+
+/* struct aa_net - network confinement data
+ * @allow: basic network families permissions
+ * @audit: which network permissions to force audit
+ * @quiet: which network permissions to quiet rejects
+ */
+struct aa_net {
+	u16 allow[AF_MAX];
+	u16 audit[AF_MAX];
+	u16 quiet[AF_MAX];
+};
+
+
+extern struct aa_sfs_entry aa_sfs_entry_network[];
+
+void audit_net_cb(struct audit_buffer *ab, void *va);
+int aa_profile_af_perm(struct aa_profile *profile, struct common_audit_data *sa,
+		       u32 request, u16 family, int type);
+int aa_af_perm(struct aa_label *label, const char *op, u32 request, u16 family,
+	       int type, int protocol);
+static inline int aa_profile_af_sk_perm(struct aa_profile *profile,
+					struct common_audit_data *sa,
+					u32 request,
+					struct sock *sk)
+{
+	return aa_profile_af_perm(profile, sa, request, sk->sk_family,
+				  sk->sk_type);
+}
+int aa_sk_perm(const char *op, u32 request, struct sock *sk);
+
+int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request,
+		      struct socket *sock);
+
+
+static inline void aa_free_net_rules(struct aa_net *new)
+{
+	/* NOP */
+}
+
+#endif /* __AA_NET_H */
diff --git a/security/apparmor/include/perms.h b/security/apparmor/include/perms.h
index 2b27bb79aec4..af04d5a7d73d 100644
--- a/security/apparmor/include/perms.h
+++ b/security/apparmor/include/perms.h
@@ -135,9 +135,10 @@ extern struct aa_perms allperms;
 
 
 void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask);
-void aa_audit_perm_names(struct audit_buffer *ab, const char **names, u32 mask);
+void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names,
+			 u32 mask);
 void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
-			u32 chrsmask, const char **names, u32 namesmask);
+			u32 chrsmask, const char * const *names, u32 namesmask);
 void aa_apply_modes_to_perms(struct aa_profile *profile,
 			     struct aa_perms *perms);
 void aa_compute_perms(struct aa_dfa *dfa, unsigned int state,
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 17fe41a9cac3..4364088a0b9e 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -30,6 +30,7 @@
 #include "file.h"
 #include "lib.h"
 #include "label.h"
+#include "net.h"
 #include "perms.h"
 #include "resource.h"
 
@@ -111,6 +112,7 @@ struct aa_data {
  * @policy: general match rules governing policy
  * @file: The set of rules governing basic file access and domain transitions
  * @caps: capabilities for the profile
+ * @net: network controls for the profile
  * @rlimits: rlimits for the profile
  *
  * @dents: dentries for the profiles file entries in apparmorfs
@@ -148,6 +150,7 @@ struct aa_profile {
 	struct aa_policydb policy;
 	struct aa_file_rules file;
 	struct aa_caps caps;
+	struct aa_net net;
 	struct aa_rlimit rlimits;
 
 	struct aa_loaddata *rawdata;
@@ -220,6 +223,16 @@ static inline unsigned int PROFILE_MEDIATES_SAFE(struct aa_profile *profile,
 	return 0;
 }
 
+static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile,
+					       u16 AF) {
+	unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
+	u16 be_af = cpu_to_be16(AF);
+
+	if (!state)
+		return 0;
+	return aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2);
+}
+
 /**
  * aa_get_profile - increment refcount on profile @p
  * @p: profile  (MAYBE NULL)
diff --git a/security/apparmor/lib.c b/security/apparmor/lib.c
index 08ca26bcca77..8818621b5d95 100644
--- a/security/apparmor/lib.c
+++ b/security/apparmor/lib.c
@@ -211,7 +211,8 @@ void aa_perm_mask_to_str(char *str, const char *chrs, u32 mask)
 	*str = '\0';
 }
 
-void aa_audit_perm_names(struct audit_buffer *ab, const char **names, u32 mask)
+void aa_audit_perm_names(struct audit_buffer *ab, const char * const *names,
+			 u32 mask)
 {
 	const char *fmt = "%s";
 	unsigned int i, perm = 1;
@@ -229,7 +230,7 @@ void aa_audit_perm_names(struct audit_buffer *ab, const char **names, u32 mask)
 }
 
 void aa_audit_perm_mask(struct audit_buffer *ab, u32 mask, const char *chrs,
-			u32 chrsmask, const char **names, u32 namesmask)
+			u32 chrsmask, const char * const *names, u32 namesmask)
 {
 	char str[33];
 
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 4ad0b3a45142..cc5ab23a2d84 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -33,6 +33,7 @@
 #include "include/context.h"
 #include "include/file.h"
 #include "include/ipc.h"
+#include "include/net.h"
 #include "include/path.h"
 #include "include/label.h"
 #include "include/policy.h"
@@ -736,6 +737,368 @@ static int apparmor_task_kill(struct task_struct *target, struct siginfo *info,
 	return error;
 }
 
+/**
+ * apparmor_sk_alloc_security - allocate and attach the sk_security field
+ */
+static int apparmor_sk_alloc_security(struct sock *sk, int family, gfp_t flags)
+{
+	struct aa_sk_ctx *ctx;
+
+	ctx = kzalloc(sizeof(*ctx), flags);
+	if (!ctx)
+		return -ENOMEM;
+
+	SK_CTX(sk) = ctx;
+
+	return 0;
+}
+
+/**
+ * apparmor_sk_free_security - free the sk_security field
+ */
+static void apparmor_sk_free_security(struct sock *sk)
+{
+	struct aa_sk_ctx *ctx = SK_CTX(sk);
+
+	SK_CTX(sk) = NULL;
+	aa_put_label(ctx->label);
+	aa_put_label(ctx->peer);
+	path_put(&ctx->path);
+	kfree(ctx);
+}
+
+/**
+ * apparmor_clone_security - clone the sk_security field
+ */
+static void apparmor_sk_clone_security(const struct sock *sk,
+				       struct sock *newsk)
+{
+	struct aa_sk_ctx *ctx = SK_CTX(sk);
+	struct aa_sk_ctx *new = SK_CTX(newsk);
+
+	new->label = aa_get_label(ctx->label);
+	new->peer = aa_get_label(ctx->peer);
+	new->path = ctx->path;
+	path_get(&new->path);
+}
+
+static int aa_sock_create_perm(struct aa_label *label, int family, int type,
+			       int protocol)
+{
+	AA_BUG(!label);
+	AA_BUG(in_interrupt());
+
+	return aa_af_perm(label, OP_CREATE, AA_MAY_CREATE, family, type,
+			  protocol);
+}
+
+
+/**
+ * apparmor_socket_create - check perms before creating a new socket
+ */
+static int apparmor_socket_create(int family, int type, int protocol, int kern)
+{
+	struct aa_label *label;
+	int error = 0;
+
+	label = begin_current_label_crit_section();
+	if (!(kern || unconfined(label)))
+		error = aa_sock_create_perm(label, family, type, protocol);
+	end_current_label_crit_section(label);
+
+	return error;
+}
+
+/**
+ * apparmor_socket_post_create - setup the per-socket security struct
+ *
+ * Note:
+ * -   kernel sockets currently labeled unconfined but we may want to
+ *     move to a special kernel label
+ * -   socket may not have sk here if created with sock_create_lite or
+ *     sock_alloc. These should be accept cases which will be handled in
+ *     sock_graft.
+ */
+static int apparmor_socket_post_create(struct socket *sock, int family,
+				       int type, int protocol, int kern)
+{
+	struct aa_label *label;
+
+	if (kern) {
+		struct aa_ns *ns = aa_get_current_ns();
+
+		label = aa_get_label(ns_unconfined(ns));
+		aa_put_ns(ns);
+	} else
+		label = aa_get_current_label();
+
+	if (sock->sk) {
+		struct aa_sk_ctx *ctx = SK_CTX(sock->sk);
+
+		aa_put_label(ctx->label);
+		ctx->label = aa_get_label(label);
+	}
+	aa_put_label(label);
+
+	return 0;
+}
+
+/**
+ * apparmor_socket_bind - check perms before bind addr to socket
+ */
+static int apparmor_socket_bind(struct socket *sock,
+				struct sockaddr *address, int addrlen)
+{
+	AA_BUG(!sock);
+	AA_BUG(!sock->sk);
+	AA_BUG(!address);
+	AA_BUG(in_interrupt());
+
+	return aa_sk_perm(OP_BIND, AA_MAY_BIND, sock->sk);
+}
+
+/**
+ * apparmor_socket_connect - check perms before connecting @sock to @address
+ */
+static int apparmor_socket_connect(struct socket *sock,
+				   struct sockaddr *address, int addrlen)
+{
+	AA_BUG(!sock);
+	AA_BUG(!sock->sk);
+	AA_BUG(!address);
+	AA_BUG(in_interrupt());
+
+	return aa_sk_perm(OP_CONNECT, AA_MAY_CONNECT, sock->sk);
+}
+
+/**
+ * apparmor_socket_list - check perms before allowing listen
+ */
+static int apparmor_socket_listen(struct socket *sock, int backlog)
+{
+	AA_BUG(!sock);
+	AA_BUG(!sock->sk);
+	AA_BUG(in_interrupt());
+
+	return aa_sk_pe