[apparmor] [PATCH 12/16] AppArmor: basic networking rules v2
John Johansen
john.johansen at canonical.com
Tue Feb 28 00:25:44 UTC 2012
This is v2 of the network patch with I think all of the fixes kees suggested
- updated copy rights
- Added comment in Make file
- Added Makefile dependencies
- renamed af_names.h to net_names.h
- added auto-generation fn for socket type names
- cleaned up auto-generate fn for af_names
- converted af_mask to a file containing the supported address families, also
auto generated.
- moved interface comment
- fixed spacing on logging fn
Base support for network mediation.
Signed-off-by: John Johansen <john.johansen at canonical.com>
---
include/linux/lsm_audit.h | 4 +
security/apparmor/.gitignore | 2 +-
security/apparmor/Makefile | 43 +++++++++-
security/apparmor/apparmorfs.c | 1 +
security/apparmor/include/net.h | 44 ++++++++++
security/apparmor/include/policy.h | 3 +
security/apparmor/lsm.c | 112 +++++++++++++++++++++++++
security/apparmor/net.c | 159 ++++++++++++++++++++++++++++++++++++
security/apparmor/policy.c | 1 +
security/apparmor/policy_unpack.c | 48 +++++++++++-
10 files changed, 412 insertions(+), 5 deletions(-)
create mode 100644 security/apparmor/include/net.h
create mode 100644 security/apparmor/net.c
diff --git a/include/linux/lsm_audit.h b/include/linux/lsm_audit.h
index 88e78de..c63979a 100644
--- a/include/linux/lsm_audit.h
+++ b/include/linux/lsm_audit.h
@@ -124,6 +124,10 @@ struct common_audit_data {
u32 denied;
uid_t ouid;
} fs;
+ struct {
+ int type, protocol;
+ struct sock *sk;
+ } net;
};
} apparmor_audit_data;
#endif
diff --git a/security/apparmor/.gitignore b/security/apparmor/.gitignore
index 4d995ae..d5b291e 100644
--- a/security/apparmor/.gitignore
+++ b/security/apparmor/.gitignore
@@ -1,6 +1,6 @@
#
# Generated include files
#
-af_names.h
+net_names.h
capability_names.h
rlim_names.h
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
index 86103ce..eed5f36 100644
--- a/security/apparmor/Makefile
+++ b/security/apparmor/Makefile
@@ -4,10 +4,9 @@ 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 sid.o file.o
-
-clean-files := capability_names.h rlim_names.h
+ resource.o sid.o file.o net.o
+clean-files := capability_names.h rlim_names.h net_names.h
# Build a lower case string table of capability names
# Transforms lines from
@@ -20,6 +19,38 @@ cmd_make-caps = echo "static const char *capability_names[] = {" > $@ ;\
-e 's/^\#define[ \t]+CAP_([A-Z0-9_]+)[ \t]+([0-9]+)/[\2] = "\L\1",/p';\
echo "};" >> $@
+# 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_FS_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 \
+ 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+ echo "};" >> $@ ;\
+ echo -n '\#define AA_FS_AF_MASK "' >> $@ ;\
+ sed -r -n 's/^\#define[ \t]+AF_([A-Z0-9_]+)[ \t]+([0-9]+)(.*)/\L\1/p'\
+ $< | tr '\n' ' ' | sed -e 's/ $$/"\n/' >> $@
+
+# Build a lower case string table of sock type names
+# Transform lines from
+# SOCK_STREAM = 1,
+# to
+# [1] = "stream",
+quiet_cmd_make-sock = GEN $@
+cmd_make-sock = echo "static const char *sock_type_names[] = {" >> $@ ;\
+ sed $^ >>$@ -r -n \
+ -e 's/^\tSOCK_([A-Z0-9_]+)[\t]+=[ \t]+([0-9]+)(.*)/[\2] = "\L\1",/p';\
+ echo "};" >> $@
# Build a lower case string table of rlimit names.
# Transforms lines from
@@ -55,6 +86,7 @@ cmd_make-rlim = echo "static const char *rlim_names[RLIM_NLIMITS] = {" > $@ ;\
tr '\n' ' ' | sed -e 's/ $$/"\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/linux/capability.h \
$(src)/Makefile
@@ -62,3 +94,8 @@ $(obj)/capability_names.h : $(srctree)/include/linux/capability.h \
$(obj)/rlim_names.h : $(srctree)/include/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 16c15ec..716e4c6 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -201,6 +201,7 @@ static struct aa_fs_entry aa_fs_entry_domain[] = {
static struct aa_fs_entry aa_fs_entry_features[] = {
AA_FS_DIR("domain", aa_fs_entry_domain),
AA_FS_DIR("file", aa_fs_entry_file),
+ AA_FS_DIR("network", aa_fs_entry_network),
AA_FS_FILE_U64("capability", VFS_CAP_FLAGS_MASK),
AA_FS_DIR("rlimit", aa_fs_entry_rlimit),
{ }
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
new file mode 100644
index 0000000..cb8a121
--- /dev/null
+++ b/security/apparmor/include/net.h
@@ -0,0 +1,44 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor network mediation definitions.
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2012 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 "apparmorfs.h"
+
+/* struct aa_net - network confinement data
+ * @allowed: basic network families permissions
+ * @audit_network: which network permissions to force audit
+ * @quiet_network: which network permissions to quiet rejects
+ */
+struct aa_net {
+ u16 allow[AF_MAX];
+ u16 audit[AF_MAX];
+ u16 quiet[AF_MAX];
+};
+
+extern struct aa_fs_entry aa_fs_entry_network[];
+
+extern int aa_net_perm(int op, struct aa_profile *profile, u16 family,
+ int type, int protocol, struct sock *sk);
+extern int aa_revalidate_sk(int op, struct sock *sk);
+
+static inline void aa_free_net_rules(struct aa_net *new)
+{
+ /* NOP */
+}
+
+#endif /* __AA_NET_H */
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 9e18e96..3f582a7 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -27,6 +27,7 @@
#include "capability.h"
#include "domain.h"
#include "file.h"
+#include "net.h"
#include "resource.h"
extern const char *profile_mode_names[];
@@ -157,6 +158,7 @@ struct aa_policydb {
* @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
*
* The AppArmor profile contains the basic confinement data. Each profile
@@ -194,6 +196,7 @@ struct aa_profile {
struct aa_policydb policy;
struct aa_file_rules file;
struct aa_caps caps;
+ struct aa_net net;
struct aa_rlimit rlimits;
};
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 3783202..7459547 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -32,6 +32,7 @@
#include "include/context.h"
#include "include/file.h"
#include "include/ipc.h"
+#include "include/net.h"
#include "include/path.h"
#include "include/policy.h"
#include "include/procattr.h"
@@ -621,6 +622,104 @@ static int apparmor_task_setrlimit(struct task_struct *task,
return error;
}
+static int apparmor_socket_create(int family, int type, int protocol, int kern)
+{
+ struct aa_profile *profile;
+ int error = 0;
+
+ if (kern)
+ return 0;
+
+ profile = __aa_current_profile();
+ if (!unconfined(profile))
+ error = aa_net_perm(OP_CREATE, profile, family, type, protocol,
+ NULL);
+ return error;
+}
+
+static int apparmor_socket_bind(struct socket *sock,
+ struct sockaddr *address, int addrlen)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_BIND, sk);
+}
+
+static int apparmor_socket_connect(struct socket *sock,
+ struct sockaddr *address, int addrlen)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_CONNECT, sk);
+}
+
+static int apparmor_socket_listen(struct socket *sock, int backlog)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_LISTEN, sk);
+}
+
+static int apparmor_socket_accept(struct socket *sock, struct socket *newsock)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_ACCEPT, sk);
+}
+
+static int apparmor_socket_sendmsg(struct socket *sock,
+ struct msghdr *msg, int size)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_SENDMSG, sk);
+}
+
+static int apparmor_socket_recvmsg(struct socket *sock,
+ struct msghdr *msg, int size, int flags)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_RECVMSG, sk);
+}
+
+static int apparmor_socket_getsockname(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_GETSOCKNAME, sk);
+}
+
+static int apparmor_socket_getpeername(struct socket *sock)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_GETPEERNAME, sk);
+}
+
+static int apparmor_socket_getsockopt(struct socket *sock, int level,
+ int optname)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_GETSOCKOPT, sk);
+}
+
+static int apparmor_socket_setsockopt(struct socket *sock, int level,
+ int optname)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_SETSOCKOPT, sk);
+}
+
+static int apparmor_socket_shutdown(struct socket *sock, int how)
+{
+ struct sock *sk = sock->sk;
+
+ return aa_revalidate_sk(OP_SOCK_SHUTDOWN, sk);
+}
+
static struct security_operations apparmor_ops = {
.name = "apparmor",
@@ -652,6 +751,19 @@ static struct security_operations apparmor_ops = {
.getprocattr = apparmor_getprocattr,
.setprocattr = apparmor_setprocattr,
+ .socket_create = apparmor_socket_create,
+ .socket_bind = apparmor_socket_bind,
+ .socket_connect = apparmor_socket_connect,
+ .socket_listen = apparmor_socket_listen,
+ .socket_accept = apparmor_socket_accept,
+ .socket_sendmsg = apparmor_socket_sendmsg,
+ .socket_recvmsg = apparmor_socket_recvmsg,
+ .socket_getsockname = apparmor_socket_getsockname,
+ .socket_getpeername = apparmor_socket_getpeername,
+ .socket_getsockopt = apparmor_socket_getsockopt,
+ .socket_setsockopt = apparmor_socket_setsockopt,
+ .socket_shutdown = apparmor_socket_shutdown,
+
.cred_alloc_blank = apparmor_cred_alloc_blank,
.cred_free = apparmor_cred_free,
.cred_prepare = apparmor_cred_prepare,
diff --git a/security/apparmor/net.c b/security/apparmor/net.c
new file mode 100644
index 0000000..7b96e1e
--- /dev/null
+++ b/security/apparmor/net.c
@@ -0,0 +1,159 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor network mediation
+ *
+ * Copyright (C) 1998-2008 Novell/SUSE
+ * Copyright 2009-2012 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.
+ */
+
+#include "include/apparmor.h"
+#include "include/audit.h"
+#include "include/context.h"
+#include "include/net.h"
+#include "include/policy.h"
+
+#include "net_names.h"
+
+struct aa_fs_entry aa_fs_entry_network[] = {
+ AA_FS_FILE_STRING("af_mask", AA_FS_AF_MASK),
+ { }
+};
+
+/* audit callback for net specific fields */
+static void audit_cb(struct audit_buffer *ab, void *va)
+{
+ struct common_audit_data *sa = va;
+
+ audit_log_format(ab, " family=");
+ if (address_family_names[sa->u.net.family])
+ audit_log_string(ab, address_family_names[sa->u.net.family]);
+ else
+ audit_log_format(ab, "\"unknown(%d)\"", sa->u.net.family);
+
+ audit_log_format(ab, " sock_type=");
+ if (sock_type_names[sa->aad.net.type])
+ audit_log_string(ab, sock_type_names[sa->aad.net.type]);
+ else
+ audit_log_format(ab, "\"unknown(%d)\"", sa->aad.net.type);
+
+ audit_log_format(ab, " protocol=%d", sa->aad.net.protocol);
+}
+
+/**
+ * audit_net - audit network access
+ * @profile: profile being enforced (NOT NULL)
+ * @op: operation being checked
+ * @family: network family
+ * @type: network type
+ * @protocol: network protocol
+ * @sk: socket auditing is being applied to
+ * @error: error code for failure else 0
+ *
+ * Returns: %0 or sa->error else other errorcode on failure
+ */
+static int audit_net(struct aa_profile *profile, int op, u16 family, int type,
+ int protocol, struct sock *sk, int error)
+{
+ int audit_type = AUDIT_APPARMOR_AUTO;
+ struct common_audit_data sa;
+ if (sk)
+ COMMON_AUDIT_DATA_INIT(&sa, NET);
+ else
+ COMMON_AUDIT_DATA_INIT(&sa, NONE);
+
+ /* todo fill in socket addr info */
+
+ sa.aad.op = op,
+ sa.u.net.family = family;
+ sa.u.net.sk = sk;
+ sa.aad.net.type = type;
+ sa.aad.net.protocol = protocol;
+ sa.aad.error = error;
+
+ if (likely(!sa.aad.error)) {
+ u16 audit_mask = profile->net.audit[sa.u.net.family];
+ if (likely((AUDIT_MODE(profile) != AUDIT_ALL) &&
+ !(1 << sa.aad.net.type & audit_mask)))
+ return 0;
+ audit_type = AUDIT_APPARMOR_AUDIT;
+ } else {
+ u16 quiet_mask = profile->net.quiet[sa.u.net.family];
+ u16 kill_mask = 0;
+ u16 denied = (1 << sa.aad.net.type) & ~quiet_mask;
+
+ if (denied & kill_mask)
+ audit_type = AUDIT_APPARMOR_KILL;
+
+ if ((denied & quiet_mask) &&
+ AUDIT_MODE(profile) != AUDIT_NOQUIET &&
+ AUDIT_MODE(profile) != AUDIT_ALL)
+ return COMPLAIN_MODE(profile) ? 0 : sa.aad.error;
+ }
+
+ return aa_audit(audit_type, profile, GFP_KERNEL, &sa, audit_cb);
+}
+
+/**
+ * aa_net_perm - very course network access check
+ * @op: operation being checked
+ * @profile: profile being enforced (NOT NULL)
+ * @family: network family
+ * @type: network type
+ * @protocol: network protocol
+ *
+ * Returns: %0 else error if permission denied
+ */
+int aa_net_perm(int op, struct aa_profile *profile, u16 family, int type,
+ int protocol, struct sock *sk)
+{
+ u16 family_mask;
+ int error;
+
+ if ((family < 0) || (family >= AF_MAX))
+ return -EINVAL;
+
+ if ((type < 0) || (type >= SOCK_MAX))
+ return -EINVAL;
+
+ /* unix domain and netlink sockets are handled by ipc */
+ if (family == AF_UNIX || family == AF_NETLINK)
+ return 0;
+
+ family_mask = profile->net.allow[family];
+
+ error = (family_mask & (1 << type)) ? 0 : -EACCES;
+
+ return audit_net(profile, op, family, type, protocol, sk, error);
+}
+
+/**
+ * aa_revalidate_sk - Revalidate access to a sock
+ * @op: operation being checked
+ * @sk: sock being revalidated (NOT NULL)
+ *
+ * Returns: %0 else error if permission denied
+ */
+int aa_revalidate_sk(int op, struct sock *sk)
+{
+ struct aa_profile *profile;
+ int error = 0;
+
+ /* aa_revalidate_sk should not be called from interrupt context
+ * don't mediate these calls as they are not task related
+ */
+ if (in_interrupt())
+ return 0;
+
+ profile = __aa_current_profile();
+ if (!unconfined(profile))
+ error = aa_net_perm(op, profile, sk->sk_family, sk->sk_type,
+ sk->sk_protocol, sk);
+
+ return error;
+}
diff --git a/security/apparmor/policy.c b/security/apparmor/policy.c
index 8b7febb..4be20c3 100644
--- a/security/apparmor/policy.c
+++ b/security/apparmor/policy.c
@@ -748,6 +748,7 @@ static void free_profile(struct aa_profile *profile)
aa_free_file_rules(&profile->file);
aa_free_cap_rules(&profile->caps);
+ aa_free_net_rules(&profile->net);
aa_free_rlimit_rules(&profile->rlimits);
aa_free_sid(profile->sid);
diff --git a/security/apparmor/policy_unpack.c b/security/apparmor/policy_unpack.c
index c7a6d03..6f77990 100644
--- a/security/apparmor/policy_unpack.c
+++ b/security/apparmor/policy_unpack.c
@@ -191,6 +191,19 @@ fail:
return 0;
}
+static bool unpack_u16(struct aa_ext *e, u16 *data, const char *name)
+{
+ if (unpack_nameX(e, AA_U16, name)) {
+ if (!inbounds(e, sizeof(u16)))
+ return 0;
+ if (data)
+ *data = le16_to_cpu(get_unaligned((u16 *) e->pos));
+ e->pos += sizeof(u16);
+ return 1;
+ }
+ return 0;
+}
+
static bool unpack_u32(struct aa_ext *e, u32 *data, const char *name)
{
if (unpack_nameX(e, AA_U32, name)) {
@@ -469,7 +482,8 @@ static struct aa_profile *unpack_profile(struct aa_ext *e)
{
struct aa_profile *profile = NULL;
const char *name = NULL;
- int error = -EPROTO;
+ size_t size = 0;
+ int i, error = -EPROTO;
kernel_cap_t tmpcap;
u32 tmp;
@@ -562,6 +576,38 @@ static struct aa_profile *unpack_profile(struct aa_ext *e)
if (!unpack_rlimits(e, profile))
goto fail;
+ size = unpack_array(e, "net_allowed_af");
+ if (size) {
+
+ for (i = 0; i < size; i++) {
+ /* discard extraneous rules that this kernel will
+ * never request
+ */
+ if (i >= AF_MAX) {
+ u16 tmp;
+ if (!unpack_u16(e, &tmp, NULL) ||
+ !unpack_u16(e, &tmp, NULL) ||
+ !unpack_u16(e, &tmp, NULL))
+ goto fail;
+ continue;
+ }
+ if (!unpack_u16(e, &profile->net.allow[i], NULL))
+ goto fail;
+ if (!unpack_u16(e, &profile->net.audit[i], NULL))
+ goto fail;
+ if (!unpack_u16(e, &profile->net.quiet[i], NULL))
+ goto fail;
+ }
+ if (!unpack_nameX(e, AA_ARRAYEND, NULL))
+ goto fail;
+ }
+ /*
+ * allow unix domain and netlink sockets they are handled
+ * by IPC
+ */
+ profile->net.allow[AF_UNIX] = 0xffff;
+ profile->net.allow[AF_NETLINK] = 0xffff;
+
if (unpack_nameX(e, AA_STRUCT, "policydb")) {
/* generic policy dfa - optional and may be NULL */
profile->policy.dfa = unpack_dfa(e);
--
1.7.9
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