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Ubuntu AppArmor Socket Mediation Patch
diff --git a/security/apparmor/Makefile b/security/apparmor/Makefile
index ff23fcf..fad407f 100644
--- a/security/apparmor/Makefile
+++ b/security/apparmor/Makefile
@@ -5,7 +5,8 @@ obj-$(CONFIG_SECURITY_APPARMOR) += apparmor.o
apparmor-y := apparmorfs.o audit.o capability.o task.o ipc.o lib.o match.o \
path.o domain.o policy.o policy_unpack.o procattr.o lsm.o \
- resource.o secid.o file.o policy_ns.o label.o mount.o net.o
+ resource.o secid.o file.o policy_ns.o label.o mount.o net.o \
+ af_unix.o
apparmor-$(CONFIG_SECURITY_APPARMOR_HASH) += crypto.o
clean-files := capability_names.h rlim_names.h net_names.h
diff --git a/security/apparmor/af_unix.c b/security/apparmor/af_unix.c
new file mode 100644
index 0000000..54b3796
--- /dev/null
+++ b/security/apparmor/af_unix.c
@@ -0,0 +1,652 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor af_unix fine grained mediation
+ *
+ * Copyright 2018 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 <net/tcp_states.h>
+
+#include "include/audit.h"
+#include "include/af_unix.h"
+#include "include/apparmor.h"
+#include "include/file.h"
+#include "include/label.h"
+#include "include/path.h"
+#include "include/policy.h"
+#include "include/cred.h"
+
+static inline struct sock *aa_sock(struct unix_sock *u)
+{
+ return &u->sk;
+}
+
+static inline int unix_fs_perm(const char *op, u32 mask, struct aa_label *label,
+ struct unix_sock *u, int flags)
+{
+ AA_BUG(!label);
+ AA_BUG(!u);
+ AA_BUG(!UNIX_FS(aa_sock(u)));
+
+ if (unconfined(label) || !LABEL_MEDIATES(label, AA_CLASS_FILE))
+ return 0;
+
+ mask &= NET_FS_PERMS;
+ if (!u->path.dentry) {
+ struct path_cond cond = { };
+ struct aa_perms perms = { };
+ struct aa_profile *profile;
+
+ /* socket path has been cleared because it is being shutdown
+ * can only fall back to original sun_path request
+ */
+ struct aa_sk_ctx *ctx = SK_CTX(&u->sk);
+ if (ctx->path.dentry)
+ return aa_path_perm(op, label, &ctx->path, flags, mask,
+ &cond);
+ return fn_for_each_confined(label, profile,
+ ((flags | profile->path_flags) & PATH_MEDIATE_DELETED) ?
+ __aa_path_perm(op, profile,
+ u->addr->name->sun_path, mask,
+ &cond, flags, &perms) :
+ aa_audit_file(profile, &nullperms, op, mask,
+ u->addr->name->sun_path, NULL,
+ NULL, cond.uid,
+ "Failed name lookup - "
+ "deleted entry", -EACCES));
+ } else {
+ /* the sunpath may not be valid for this ns so use the path */
+ struct path_cond cond = { u->path.dentry->d_inode->i_uid,
+ u->path.dentry->d_inode->i_mode
+ };
+
+ return aa_path_perm(op, label, &u->path, flags, mask, &cond);
+ }
+
+ return 0;
+}
+
+/* passing in state returned by PROFILE_MEDIATES_AF */
+static unsigned int match_to_prot(struct aa_profile *profile,
+ unsigned int state, int type, int protocol,
+ const char **info)
+{
+ __be16 buffer[2];
+ buffer[0] = cpu_to_be16(type);
+ buffer[1] = cpu_to_be16(protocol);
+ state = aa_dfa_match_len(profile->policy.dfa, state, (char *) &buffer,
+ 4);
+ if (!state)
+ *info = "failed type and protocol match";
+ return state;
+}
+
+static unsigned int match_addr(struct aa_profile *profile, unsigned int state,
+ struct sockaddr_un *addr, int addrlen)
+{
+ if (addr)
+ /* include leading \0 */
+ state = aa_dfa_match_len(profile->policy.dfa, state,
+ addr->sun_path,
+ unix_addr_len(addrlen));
+ else
+ /* anonymous end point */
+ state = aa_dfa_match_len(profile->policy.dfa, state, "\x01",
+ 1);
+ /* todo change to out of band */
+ state = aa_dfa_null_transition(profile->policy.dfa, state);
+ return state;
+}
+
+static unsigned int match_to_local(struct aa_profile *profile,
+ unsigned int state, int type, int protocol,
+ struct sockaddr_un *addr, int addrlen,
+ const char **info)
+{
+ state = match_to_prot(profile, state, type, protocol, info);
+ if (state) {
+ state = match_addr(profile, state, addr, addrlen);
+ if (state) {
+ /* todo: local label matching */
+ state = aa_dfa_null_transition(profile->policy.dfa,
+ state);
+ if (!state)
+ *info = "failed local label match";
+ } else
+ *info = "failed local address match";
+ }
+
+ return state;
+}
+
+static unsigned int match_to_sk(struct aa_profile *profile,
+ unsigned int state, struct unix_sock *u,
+ const char **info)
+{
+ struct sockaddr_un *addr = NULL;
+ int addrlen = 0;
+
+ if (u->addr) {
+ addr = u->addr->name;
+ addrlen = u->addr->len;
+ }
+
+ return match_to_local(profile, state, u->sk.sk_type, u->sk.sk_protocol,
+ addr, addrlen, info);
+}
+
+#define CMD_ADDR 1
+#define CMD_LISTEN 2
+#define CMD_OPT 4
+
+static inline unsigned int match_to_cmd(struct aa_profile *profile,
+ unsigned int state, struct unix_sock *u,
+ char cmd, const char **info)
+{
+ state = match_to_sk(profile, state, u, info);
+ if (state) {
+ state = aa_dfa_match_len(profile->policy.dfa, state, &cmd, 1);
+ if (!state)
+ *info = "failed cmd selection match";
+ }
+
+ return state;
+}
+
+static inline unsigned int match_to_peer(struct aa_profile *profile,
+ unsigned int state,
+ struct unix_sock *u,
+ struct sockaddr_un *peer_addr,
+ int peer_addrlen,
+ const char **info)
+{
+ state = match_to_cmd(profile, state, u, CMD_ADDR, info);
+ if (state) {
+ state = match_addr(profile, state, peer_addr, peer_addrlen);
+ if (!state)
+ *info = "failed peer address match";
+ }
+ return state;
+}
+
+static int do_perms(struct aa_profile *profile, unsigned int state, u32 request,
+ struct common_audit_data *sa)
+{
+ struct aa_perms perms;
+
+ AA_BUG(!profile);
+
+ aa_compute_perms(profile->policy.dfa, state, &perms);
+ aa_apply_modes_to_perms(profile, &perms);
+ return aa_check_perms(profile, &perms, request, sa,
+ audit_net_cb);
+}
+
+static int match_label(struct aa_profile *profile, struct aa_profile *peer,
+ unsigned int state, u32 request,
+ struct common_audit_data *sa)
+{
+ AA_BUG(!profile);
+ AA_BUG(!peer);
+
+ aad(sa)->peer = &peer->label;
+
+ if (state) {
+ state = aa_dfa_match(profile->policy.dfa, state,
+ peer->base.hname);
+ if (!state)
+ aad(sa)->info = "failed peer label match";
+ }
+ return do_perms(profile, state, request, sa);
+}
+
+
+/* unix sock creation comes before we know if the socket will be an fs
+ * socket
+ * v6 - semantics are handled by mapping in profile load
+ * v7 - semantics require sock create for tasks creating an fs socket.
+ */
+static int profile_create_perm(struct aa_profile *profile, int family,
+ int type, int protocol)
+{
+ unsigned int state;
+ DEFINE_AUDIT_NET(sa, OP_CREATE, NULL, family, type, protocol);
+
+ AA_BUG(!profile);
+ AA_BUG(profile_unconfined(profile));
+
+ if ((state = PROFILE_MEDIATES_AF(profile, AF_UNIX))) {
+ state = match_to_prot(profile, state, type, protocol,
+ &aad(&sa)->info);
+ return do_perms(profile, state, AA_MAY_CREATE, &sa);
+ }
+
+ return aa_profile_af_perm(profile, &sa, AA_MAY_CREATE, family, type);
+}
+
+int aa_unix_create_perm(struct aa_label *label, int family, int type,
+ int protocol)
+{
+ struct aa_profile *profile;
+
+ if (unconfined(label))
+ return 0;
+
+ return fn_for_each_confined(label, profile,
+ profile_create_perm(profile, family, type, protocol));
+}
+
+
+static inline int profile_sk_perm(struct aa_profile *profile, const char *op,
+ u32 request, struct sock *sk)
+{
+ unsigned int state;
+ DEFINE_AUDIT_SK(sa, op, sk);
+
+ AA_BUG(!profile);
+ AA_BUG(!sk);
+ AA_BUG(UNIX_FS(sk));
+ AA_BUG(profile_unconfined(profile));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ state = match_to_sk(profile, state, unix_sk(sk),
+ &aad(&sa)->info);
+ return do_perms(profile, state, request, &sa);
+ }
+
+ return aa_profile_af_sk_perm(profile, &sa, request, sk);
+}
+
+int aa_unix_label_sk_perm(struct aa_label *label, const char *op, u32 request,
+ struct sock *sk)
+{
+ struct aa_profile *profile;
+
+ return fn_for_each_confined(label, profile,
+ profile_sk_perm(profile, op, request, sk));
+}
+
+static int unix_label_sock_perm(struct aa_label *label, const char *op, u32 request,
+ struct socket *sock)
+{
+ if (unconfined(label))
+ return 0;
+ if (UNIX_FS(sock->sk))
+ return unix_fs_perm(op, request, label, unix_sk(sock->sk), 0);
+
+ return aa_unix_label_sk_perm(label, op, request, sock->sk);
+}
+
+/* revaliation, get/set attr */
+int aa_unix_sock_perm(const char *op, u32 request, struct socket *sock)
+{
+ struct aa_label *label;
+ int error;
+
+ label = begin_current_label_crit_section();
+ error = unix_label_sock_perm(label, op, request, sock);
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
+static int profile_bind_perm(struct aa_profile *profile, struct sock *sk,
+ struct sockaddr *addr, int addrlen)
+{
+ unsigned int state;
+ DEFINE_AUDIT_SK(sa, OP_BIND, sk);
+
+ AA_BUG(!profile);
+ AA_BUG(!sk);
+ AA_BUG(addr->sa_family != AF_UNIX);
+ AA_BUG(profile_unconfined(profile));
+ AA_BUG(unix_addr_fs(addr, addrlen));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ /* bind for abstract socket */
+ aad(&sa)->net.addr = unix_addr(addr);
+ aad(&sa)->net.addrlen = addrlen;
+
+ state = match_to_local(profile, state,
+ sk->sk_type, sk->sk_protocol,
+ unix_addr(addr), addrlen,
+ &aad(&sa)->info);
+ return do_perms(profile, state, AA_MAY_BIND, &sa);
+ }
+
+ return aa_profile_af_sk_perm(profile, &sa, AA_MAY_BIND, sk);
+}
+
+int aa_unix_bind_perm(struct socket *sock, struct sockaddr *address,
+ int addrlen)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error = 0;
+
+ label = begin_current_label_crit_section();
+ /* fs bind is handled by mknod */
+ if (!(unconfined(label) || unix_addr_fs(address, addrlen)))
+ error = fn_for_each_confined(label, profile,
+ profile_bind_perm(profile, sock->sk, address,
+ addrlen));
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
+int aa_unix_connect_perm(struct socket *sock, struct sockaddr *address,
+ int addrlen)
+{
+ /* unix connections are covered by the
+ * - unix_stream_connect (stream) and unix_may_send hooks (dgram)
+ * - fs connect is handled by open
+ */
+ return 0;
+}
+
+static int profile_listen_perm(struct aa_profile *profile, struct sock *sk,
+ int backlog)
+{
+ unsigned int state;
+ DEFINE_AUDIT_SK(sa, OP_LISTEN, sk);
+
+ AA_BUG(!profile);
+ AA_BUG(!sk);
+ AA_BUG(UNIX_FS(sk));
+ AA_BUG(profile_unconfined(profile));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ __be16 b = cpu_to_be16(backlog);
+
+ state = match_to_cmd(profile, state, unix_sk(sk), CMD_LISTEN,
+ &aad(&sa)->info);
+ if (state) {
+ state = aa_dfa_match_len(profile->policy.dfa, state,
+ (char *) &b, 2);
+ if (!state)
+ aad(&sa)->info = "failed listen backlog match";
+ }
+ return do_perms(profile, state, AA_MAY_LISTEN, &sa);
+ }
+
+ return aa_profile_af_sk_perm(profile, &sa, AA_MAY_LISTEN, sk);
+}
+
+int aa_unix_listen_perm(struct socket *sock, int backlog)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error = 0;
+
+ label = begin_current_label_crit_section();
+ if (!(unconfined(label) || UNIX_FS(sock->sk)))
+ error = fn_for_each_confined(label, profile,
+ profile_listen_perm(profile, sock->sk,
+ backlog));
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
+
+static inline int profile_accept_perm(struct aa_profile *profile,
+ struct sock *sk,
+ struct sock *newsk)
+{
+ unsigned int state;
+ DEFINE_AUDIT_SK(sa, OP_ACCEPT, sk);
+
+ AA_BUG(!profile);
+ AA_BUG(!sk);
+ AA_BUG(UNIX_FS(sk));
+ AA_BUG(profile_unconfined(profile));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ state = match_to_sk(profile, state, unix_sk(sk),
+ &aad(&sa)->info);
+ return do_perms(profile, state, AA_MAY_ACCEPT, &sa);
+ }
+
+ return aa_profile_af_sk_perm(profile, &sa, AA_MAY_ACCEPT, sk);
+}
+
+/* ability of sock to connect, not peer address binding */
+int aa_unix_accept_perm(struct socket *sock, struct socket *newsock)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error = 0;
+
+ label = begin_current_label_crit_section();
+ if (!(unconfined(label) || UNIX_FS(sock->sk)))
+ error = fn_for_each_confined(label, profile,
+ profile_accept_perm(profile, sock->sk,
+ newsock->sk));
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
+
+/* dgram handled by unix_may_sendmsg, right to send on stream done at connect
+ * could do per msg unix_stream here
+ */
+/* sendmsg, recvmsg */
+int aa_unix_msg_perm(const char *op, u32 request, struct socket *sock,
+ struct msghdr *msg, int size)
+{
+ return 0;
+}
+
+
+static int profile_opt_perm(struct aa_profile *profile, const char *op, u32 request,
+ struct sock *sk, int level, int optname)
+{
+ unsigned int state;
+ DEFINE_AUDIT_SK(sa, op, sk);
+
+ AA_BUG(!profile);
+ AA_BUG(!sk);
+ AA_BUG(UNIX_FS(sk));
+ AA_BUG(profile_unconfined(profile));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ __be16 b = cpu_to_be16(optname);
+
+ state = match_to_cmd(profile, state, unix_sk(sk), CMD_OPT,
+ &aad(&sa)->info);
+ if (state) {
+ state = aa_dfa_match_len(profile->policy.dfa, state,
+ (char *) &b, 2);
+ if (!state)
+ aad(&sa)->info = "failed sockopt match";
+ }
+ return do_perms(profile, state, request, &sa);
+ }
+
+ return aa_profile_af_sk_perm(profile, &sa, request, sk);
+}
+
+int aa_unix_opt_perm(const char *op, u32 request, struct socket *sock, int level,
+ int optname)
+{
+ struct aa_profile *profile;
+ struct aa_label *label;
+ int error = 0;
+
+ label = begin_current_label_crit_section();
+ if (!(unconfined(label) || UNIX_FS(sock->sk)))
+ error = fn_for_each_confined(label, profile,
+ profile_opt_perm(profile, op, request,
+ sock->sk, level, optname));
+ end_current_label_crit_section(label);
+
+ return error;
+}
+
+/* null peer_label is allowed, in which case the peer_sk label is used */
+static int profile_peer_perm(struct aa_profile *profile, const char *op, u32 request,
+ struct sock *sk, struct sock *peer_sk,
+ struct aa_label *peer_label,
+ struct common_audit_data *sa)
+{
+ unsigned int state;
+
+ AA_BUG(!profile);
+ AA_BUG(profile_unconfined(profile));
+ AA_BUG(!sk);
+ AA_BUG(!peer_sk);
+ AA_BUG(UNIX_FS(peer_sk));
+
+ state = PROFILE_MEDIATES_AF(profile, AF_UNIX);
+ if (state) {
+ struct aa_sk_ctx *peer_ctx = SK_CTX(peer_sk);
+ struct aa_profile *peerp;
+ struct sockaddr_un *addr = NULL;
+ int len = 0;
+ if (unix_sk(peer_sk)->addr) {
+ addr = unix_sk(peer_sk)->addr->name;
+ len = unix_sk(peer_sk)->addr->len;
+ }
+ state = match_to_peer(profile, state, unix_sk(sk),
+ addr, len, &aad(sa)->info);
+ if (!peer_label)
+ peer_label = peer_ctx->label;
+ return fn_for_each_in_ns(peer_label, peerp,
+ match_label(profile, peerp, state, request,
+ sa));
+ }
+
+ return aa_profile_af_sk_perm(profile, sa, request, sk);
+}
+
+/**
+ *
+ * Requires: lock held on both @sk and @peer_sk
+ */
+int aa_unix_peer_perm(struct aa_label *label, const char *op, u32 request,
+ struct sock *sk, struct sock *peer_sk,
+ struct aa_label *peer_label)
+{
+ struct unix_sock *peeru = unix_sk(peer_sk);
+ struct unix_sock *u = unix_sk(sk);
+
+ AA_BUG(!label);
+ AA_BUG(!sk);
+ AA_BUG(!peer_sk);
+
+ if (UNIX_FS(aa_sock(peeru)))
+ return unix_fs_perm(op, request, label, peeru, 0);
+ else if (UNIX_FS(aa_sock(u)))
+ return unix_fs_perm(op, request, label, u, 0);
+ else {
+ struct aa_profile *profile;
+ DEFINE_AUDIT_SK(sa, op, sk);
+ aad(&sa)->net.peer_sk = peer_sk;
+
+ /* TODO: ns!!! */
+ if (!net_eq(sock_net(sk), sock_net(peer_sk))) {
+ ;
+ }
+
+ if (unconfined(label))
+ return 0;
+
+ return fn_for_each_confined(label, profile,
+ profile_peer_perm(profile, op, request, sk,
+ peer_sk, peer_label, &sa));
+ }
+}
+
+
+/* from net/unix/af_unix.c */
+static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
+{
+ if (unlikely(sk1 == sk2) || !sk2) {
+ unix_state_lock(sk1);
+ return;
+ }
+ if (sk1 < sk2) {
+ unix_state_lock(sk1);
+ unix_state_lock_nested(sk2);
+ } else {
+ unix_state_lock(sk2);
+ unix_state_lock_nested(sk1);
+ }
+}
+
+static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
+{
+ if (unlikely(sk1 == sk2) || !sk2) {
+ unix_state_unlock(sk1);
+ return;
+ }
+ unix_state_unlock(sk1);
+ unix_state_unlock(sk2);
+}
+
+int aa_unix_file_perm(struct aa_label *label, const char *op, u32 request,
+ struct socket *sock)
+{
+ struct sock *peer_sk = NULL;
+ u32 sk_req = request & ~NET_PEER_MASK;
+ int error = 0;
+
+ AA_BUG(!label);
+ AA_BUG(!sock);
+ AA_BUG(!sock->sk);
+ AA_BUG(sock->sk->sk_family != AF_UNIX);
+
+ /* TODO: update sock label with new task label */
+ unix_state_lock(sock->sk);
+ peer_sk = unix_peer(sock->sk);
+ if (peer_sk)
+ sock_hold(peer_sk);
+ if (!unix_connected(sock) && sk_req) {
+ error = unix_label_sock_perm(label, op, sk_req, sock);
+ if (!error) {
+ // update label
+ }
+ }
+ unix_state_unlock(sock->sk);
+ if (!peer_sk)
+ return error;
+
+ unix_state_double_lock(sock->sk, peer_sk);
+ if (UNIX_FS(sock->sk)) {
+ error = unix_fs_perm(op, request, label, unix_sk(sock->sk),
+ PATH_SOCK_COND);
+ } else if (UNIX_FS(peer_sk)) {
+ error = unix_fs_perm(op, request, label, unix_sk(peer_sk),
+ PATH_SOCK_COND);
+ } else {
+ struct aa_sk_ctx *pctx = SK_CTX(peer_sk);
+ if (sk_req)
+ error = aa_unix_label_sk_perm(label, op, sk_req,
+ sock->sk);
+ last_error(error,
+ xcheck(aa_unix_peer_perm(label, op,
+ MAY_READ | MAY_WRITE,
+ sock->sk, peer_sk, NULL),
+ aa_unix_peer_perm(pctx->label, op,
+ MAY_READ | MAY_WRITE,
+ peer_sk, sock->sk, label)));
+ }
+
+ unix_state_double_unlock(sock->sk, peer_sk);
+ sock_put(peer_sk);
+
+ return error;
+}
diff --git a/security/apparmor/apparmorfs.c b/security/apparmor/apparmorfs.c
index 32f0e66..b931bae 100644
--- a/security/apparmor/apparmorfs.c
+++ b/security/apparmor/apparmorfs.c
@@ -2256,6 +2256,11 @@ static struct aa_sfs_entry aa_sfs_entry_ns[] = {
{ }
};
+static struct aa_sfs_entry aa_sfs_entry_dbus[] = {
+ AA_SFS_FILE_STRING("mask", "acquire send receive"),
+ { }
+};
+
static struct aa_sfs_entry aa_sfs_entry_query_label[] = {
AA_SFS_FILE_STRING("perms", "allow deny audit quiet"),
AA_SFS_FILE_BOOLEAN("data", 1),
@@ -2280,6 +2285,7 @@ static struct aa_sfs_entry aa_sfs_entry_features[] = {
AA_SFS_DIR("caps", aa_sfs_entry_caps),
AA_SFS_DIR("ptrace", aa_sfs_entry_ptrace),
AA_SFS_DIR("signal", aa_sfs_entry_signal),
+ AA_SFS_DIR("dbus", aa_sfs_entry_dbus),
AA_SFS_DIR("query", aa_sfs_entry_query),
{ }
};
diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index 224b2fe..67e70e0 100644
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -16,6 +16,7 @@
#include <linux/fdtable.h>
#include <linux/file.h>
+#include "include/af_unix.h"
#include "include/apparmor.h"
#include "include/audit.h"
#include "include/cred.h"
@@ -283,7 +284,8 @@ int __aa_path_perm(const char *op, struct aa_profile *profile, const char *name,
{
int e = 0;
- if (profile_unconfined(profile))
+ if (profile_unconfined(profile) ||
+ ((flags & PATH_SOCK_COND) && !PROFILE_MEDIATES_AF(profile, AF_UNIX)))
return 0;
aa_str_perms(profile->file.dfa, profile->file.start, name, cond, perms);
if (request & ~perms->allow)
diff --git a/security/apparmor/include/af_unix.h b/security/apparmor/include/af_unix.h
new file mode 100644
index 0000000..d1b7f23
--- /dev/null
+++ b/security/apparmor/include/af_unix.h
@@ -0,0 +1,114 @@
+/*
+ * AppArmor security module
+ *
+ * This file contains AppArmor af_unix fine grained mediation
+ *
+ * Copyright 2014 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_AF_UNIX_H
+
+#include <net/af_unix.h>
+
+#include "label.h"
+//#include "include/net.h"
+
+#define unix_addr_len(L) ((L) - sizeof(sa_family_t))
+#define unix_abstract_name_len(L) (unix_addr_len(L) - 1)
+#define unix_abstract_len(U) (unix_abstract_name_len((U)->addr->len))
+#define addr_unix_abstract_name(B) ((B)[0] == 0)
+#define addr_unix_anonymous(U) (addr_unix_len(U) <= 0)
+#define addr_unix_abstract(U) (!addr_unix_anonymous(U) && addr_unix_abstract_name((U)->addr))
+//#define unix_addr_fs(U) (!unix_addr_anonymous(U) && !unix_addr_abstract_name((U)->addr))
+
+#define unix_addr(A) ((struct sockaddr_un *)(A))
+#define unix_addr_anon(A, L) ((A) && unix_addr_len(L) <= 0)
+#define unix_addr_fs(A, L) (!unix_addr_anon(A, L) && !addr_unix_abstract_name(unix_addr(A)->sun_path))
+
+#define UNIX_ANONYMOUS(U) (!unix_sk(U)->addr)
+/* from net/unix/af_unix.c */
+#define UNIX_ABSTRACT(U) (!UNIX_ANONYMOUS(U) && \
+ unix_sk(U)->addr->hash < UNIX_HASH_SIZE)
+#define UNIX_FS(U) (!UNIX_ANONYMOUS(U) && unix_sk(U)->addr->name->sun_path[0])
+#define unix_peer(sk) (unix_sk(sk)->peer)
+#define unix_connected(S) ((S)->state == SS_CONNECTED)
+
+static inline void print_unix_addr(struct sockaddr_un *A, int L)
+{
+ char *buf = (A) ? (char *) &(A)->sun_path : NULL;
+ int len = unix_addr_len(L);
+ if (!buf || len <= 0)
+ printk(" <anonymous>");
+ else if (buf[0])
+ printk(" %s", buf);
+ else
+ /* abstract name len includes leading \0 */
+ printk(" %d @%.*s", len - 1, len - 1, buf+1);
+};
+
+/*
+ printk("%s: %s: f %d, t %d, p %d", __FUNCTION__, \
+ #SK , \
+*/
+#define print_unix_sk(SK) \
+do { \
+ struct unix_sock *u = unix_sk(SK); \
+ printk("%s: f %d, t %d, p %d", #SK , \
+ (SK)->sk_family, (SK)->sk_type, (SK)->sk_protocol); \
+ if (u->addr) \
+ print_unix_addr(u->addr->name, u->addr->len); \
+ else \
+ print_unix_addr(NULL, sizeof(sa_family_t)); \
+ /* printk("\n");*/ \
+} while (0)
+
+#define print_sk(SK) \
+do { \
+ if (!(SK)) { \
+ printk("%s: %s is null\n", __FUNCTION__, #SK); \
+ } else if ((SK)->sk_family == PF_UNIX) { \
+ print_unix_sk(SK); \
+ printk("\n"); \
+ } else { \
+ printk("%s: %s: family %d\n", __FUNCTION__, #SK , \
+ (SK)->sk_family); \
+ } \
+} while (0)
+
+#define print_sock_addr(U) \
+do { \
+ printk("%s:\n", __FUNCTION__); \
+ printk(" sock %s:", sock_ctx && sock_ctx->label ? aa_label_printk(sock_ctx->label, GFP_ATOMIC); : "<null>"); print_sk(sock); \
+ printk(" other %s:", other_ctx && other_ctx->label ? aa_label_printk(other_ctx->label, GFP_ATOMIC); : "<null>"); print_sk(other); \
+ printk(" new %s", new_ctx && new_ctx->label ? aa_label_printk(new_ctx->label, GFP_ATOMIC); : "<null>"); print_sk(newsk); \
+} while (0)
+
+
+
+
+int aa_unix_peer_perm(struct aa_label *label, const char *op, u32 request,
+ struct sock *sk, struct sock *peer_sk,
+ struct aa_label *peer_label);
+int aa_unix_label_sk_perm(struct aa_label *label, const char *op, u32 request,
+ struct sock *sk);
+int aa_unix_sock_perm(const char *op, u32 request, struct socket *sock);
+int aa_unix_create_perm(struct aa_label *label, int family, int type,
+ int protocol);
+int aa_unix_bind_perm(struct socket *sock, struct sockaddr *address,
+ int addrlen);
+int aa_unix_connect_perm(struct socket *sock, struct sockaddr *address,
+ int addrlen);
+int aa_unix_listen_perm(struct socket *sock, int backlog);
+int aa_unix_accept_perm(struct socket *sock, struct socket *newsock);
+int aa_unix_msg_perm(const char *op, u32 request, struct socket *sock,
+ struct msghdr *msg, int size);
+int aa_unix_opt_perm(const char *op, u32 request, struct socket *sock, int level,
+ int optname);
+int aa_unix_file_perm(struct aa_label *label, const char *op, u32 request,
+ struct socket *sock);
+
+#endif /* __AA_AF_UNIX_H */
diff --git a/security/apparmor/include/net.h b/security/apparmor/include/net.h
index 579b59a..48e07dc 100644
--- a/security/apparmor/include/net.h
+++ b/security/apparmor/include/net.h
@@ -53,6 +53,7 @@
struct aa_sk_ctx {
struct aa_label *label;
struct aa_label *peer;
+ struct path path;
};
#define SK_CTX(X) ((X)->sk_security)
@@ -87,6 +88,9 @@ struct aa_net_compat {
({ \
int __e; \
switch ((FAMILY)) { \
+ case AF_UNIX: \
+ __e = aa_unix_ ## FN; \
+ break; \
default: \
__e = DEF_FN; \
} \
diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h
index b6380c5..ab1c3e4 100644
--- a/security/apparmor/include/path.h
+++ b/security/apparmor/include/path.h
@@ -18,6 +18,7 @@
enum path_flags {
PATH_IS_DIR = 0x1, /* path is a directory */
+ PATH_SOCK_COND = 0x2,
PATH_CONNECT_PATH = 0x4, /* connect disconnected paths to / */
PATH_CHROOT_REL = 0x8, /* do path lookup relative to chroot */
PATH_CHROOT_NSCONNECT = 0x10, /* connect paths that are at ns root */
diff --git a/security/apparmor/include/policy.h b/security/apparmor/include/policy.h
index 4006fa9..35da41f 100644
--- a/security/apparmor/include/policy.h
+++ b/security/apparmor/include/policy.h
@@ -232,9 +232,13 @@ static inline unsigned int PROFILE_MEDIATES_AF(struct aa_profile *profile,
unsigned int state = PROFILE_MEDIATES(profile, AA_CLASS_NET);
__be16 be_af = cpu_to_be16(AF);
- if (!state)
- return 0;
- return aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2);
+ if (!state) {
+ state = PROFILE_MEDIATES(profile, AA_CLASS_NET_COMPAT);
+ if (!state)
+ return 0;
+ }
+ state = aa_dfa_match_len(profile->policy.dfa, state, (char *) &be_af, 2);
+ return state;
}
/**
diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c
index 74f1737..ed4cd92 100644
--- a/security/apparmor/lsm.c
+++ b/security/apparmor/lsm.c
@@ -25,6 +25,7 @@
#include <linux/user_namespace.h>
#include <net/sock.h>
+#include "include/af_unix.h"
#include "include/apparmor.h"
#include "include/apparmorfs.h"
#include "include/audit.h"
@@ -785,6 +786,7 @@ static void apparmor_sk_free_security(struct sock *sk)
SK_CTX(sk) = NULL;
aa_put_label(ctx->label);
aa_put_label(ctx->peer);
+ path_put(&ctx->path);
kfree(ctx);
}
@@ -799,6 +801,99 @@ static void apparmor_sk_clone_security(const struct sock *sk,
new->label = aa_get_label(ctx->label);
new->peer = aa_get_label(ctx->peer);
+ new->path = ctx->path;
+ path_get(&new->path);
+}
+
+static struct path *UNIX_FS_CONN_PATH(struct sock *sk, struct sock *newsk)
+{
+ if (sk->sk_family == PF_UNIX && UNIX_FS(sk))
+ return &unix_sk(sk)->path;
+ else if (newsk->sk_family == PF_UNIX && UNIX_FS(newsk))
+ return &unix_sk(newsk)->path;
+ return NULL;
+}
+
+/**
+ * apparmor_unix_stream_connect - check perms before making unix domain conn
+ *
+ * peer is locked when this hook is called
+ */
+static int apparmor_unix_stream_connect(struct sock *sk, struct sock *peer_sk,
+ struct sock *newsk)
+{
+ struct aa_sk_ctx *sk_ctx = SK_CTX(sk);
+ struct aa_sk_ctx *peer_ctx = SK_CTX(peer_sk);
+ struct aa_sk_ctx *new_ctx = SK_CTX(newsk);
+ struct aa_label *label;
+ struct path *path;
+ int error;
+
+ label = __begin_current_label_crit_section();
+ error = aa_unix_peer_perm(label, OP_CONNECT,
+ (AA_MAY_CONNECT | AA_MAY_SEND | AA_MAY_RECEIVE),
+ sk, peer_sk, NULL);
+ if (!UNIX_FS(peer_sk)) {
+ last_error(error,
+ aa_unix_peer_perm(peer_ctx->label, OP_CONNECT,
+ (AA_MAY_ACCEPT | AA_MAY_SEND | AA_MAY_RECEIVE),
+ peer_sk, sk, label));
+ }
+ __end_current_label_crit_section(label);
+
+ if (error)
+ return error;
+
+ /* label newsk if it wasn't labeled in post_create. Normally this
+ * would be done in sock_graft, but because we are directly looking
+ * at the peer_sk to obtain peer_labeling for unix socks this
+ * does not work
+ */
+ if (!new_ctx->label)
+ new_ctx->label = aa_get_label(peer_ctx->label);
+
+ /* Cross reference the peer labels for SO_PEERSEC */
+ if (new_ctx->peer)
+ aa_put_label(new_ctx->peer);
+
+ if (sk_ctx->peer)
+ aa_put_label(sk_ctx->peer);
+
+ new_ctx->peer = aa_get_label(sk_ctx->label);
+ sk_ctx->peer = aa_get_label(peer_ctx->label);
+
+ path = UNIX_FS_CONN_PATH(sk, peer_sk);
+ if (path) {
+ new_ctx->path = *path;
+ sk_ctx->path = *path;
+ path_get(path);
+ path_get(path);
+ }
+ return 0;
+}
+
+/**
+ * apparmor_unix_may_send - check perms before conn or sending unix dgrams
+ *
+ * other is locked when this hook is called
+ *
+ * dgram connect calls may_send, peer setup but path not copied?????
+ */
+static int apparmor_unix_may_send(struct socket *sock, struct socket *peer)
+{
+ struct aa_sk_ctx *peer_ctx = SK_CTX(peer->sk);
+ struct aa_label *label;
+ int error;
+
+ label = __begin_current_label_crit_section();
+ error = xcheck(aa_unix_peer_perm(label, OP_SENDMSG, AA_MAY_SEND,
+ sock->sk, peer->sk, NULL),
+ aa_unix_peer_perm(peer_ctx->label, OP_SENDMSG,
+ AA_MAY_RECEIVE,
+ peer->sk, sock->sk, label));
+ __end_current_label_crit_section(label);
+
+ return error;
}
/**
@@ -1036,11 +1131,25 @@ static int apparmor_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
static struct aa_label *sk_peer_label(struct sock *sk)
{
+ struct sock *peer_sk;
struct aa_sk_ctx *ctx = SK_CTX(sk);
if (ctx->peer)
return ctx->peer;
+ if (sk->sk_family != PF_UNIX)
+ return ERR_PTR(-ENOPROTOOPT);
+
+ /* check for sockpair peering which does not go through
+ * security_unix_stream_connect
+ */
+ peer_sk = unix_peer(sk);
+ if (peer_sk) {
+ ctx = SK_CTX(peer_sk);
+ if (ctx->label)
+ return ctx->label;
+ }
+
return ERR_PTR(-ENOPROTOOPT);
}
@@ -1164,6 +1273,9 @@ static struct security_hook_list apparmor_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(sk_free_security, apparmor_sk_free_security),
LSM_HOOK_INIT(sk_clone_security, apparmor_sk_clone_security),
+ LSM_HOOK_INIT(unix_stream_connect, apparmor_unix_stream_connect),
+ LSM_HOOK_INIT(unix_may_send, apparmor_unix_may_send),
+
LSM_HOOK_INIT(socket_create, apparmor_socket_create),
LSM_HOOK_INIT(socket_post_create, apparmor_socket_post_create),
LSM_HOOK_INIT(socket_bind, apparmor_socket_bind),
diff --git a/security/apparmor/net.c b/security/apparmor/net.c
index bf6aaef..042aee4 100644
--- a/security/apparmor/net.c
+++ b/security/apparmor/net.c
@@ -12,6 +12,7 @@
* License.
*/
+#include "include/af_unix.h"
#include "include/apparmor.h"
#include "include/audit.h"
#include "include/cred.h"
@@ -29,6 +30,7 @@ struct aa_sfs_entry aa_sfs_entry_network[] = {
struct aa_sfs_entry aa_sfs_entry_network_compat[] = {
AA_SFS_FILE_STRING("af_mask", AA_SFS_AF_MASK),
+ AA_SFS_FILE_BOOLEAN("af_unix", 1),
{ }
};
@@ -74,6 +76,36 @@ static const char * const net_mask_names[] = {
"unknown",
};
+static void audit_unix_addr(struct audit_buffer *ab, const char *str,
+ struct sockaddr_un *addr, int addrlen)
+{
+ int len = unix_addr_len(addrlen);
+
+ if (!addr || len <= 0) {
+ audit_log_format(ab, " %s=none", str);
+ } else if (addr->sun_path[0]) {
+ audit_log_format(ab, " %s=", str);
+ audit_log_untrustedstring(ab, addr->sun_path);
+ } else {
+ audit_log_format(ab, " %s=\"@", str);
+ if (audit_string_contains_control(&addr->sun_path[1], len - 1))
+ audit_log_n_hex(ab, &addr->sun_path[1], len - 1);
+ else
+ audit_log_format(ab, "%.*s", len - 1,
+ &addr->sun_path[1]);
+ audit_log_format(ab, "\"");
+ }
+}
+
+static void audit_unix_sk_addr(struct audit_buffer *ab, const char *str,
+ struct sock *sk)
+{
+ struct unix_sock *u = unix_sk(sk);
+ if (u && u->addr)
+ audit_unix_addr(ab, str, u->addr->name, u->addr->len);
+ else
+ audit_unix_addr(ab, str, NULL, 0);
+}
/* audit callback for net specific fields */
void audit_net_cb(struct audit_buffer *ab, void *va)
@@ -103,6 +135,23 @@ void audit_net_cb(struct audit_buffer *ab, void *va)
net_mask_names, NET_PERMS_MASK);
}
}
+ if (sa->u.net->family == AF_UNIX) {
+ if ((aad(sa)->request & ~NET_PEER_MASK) && aad(sa)->net.addr)
+ audit_unix_addr(ab, "addr",
+ unix_addr(aad(sa)->net.addr),
+ aad(sa)->net.addrlen);
+ else
+ audit_unix_sk_addr(ab, "addr", sa->u.net->sk);
+ if (aad(sa)->request & NET_PEER_MASK) {
+ if (aad(sa)->net.addr)
+ audit_unix_addr(ab, "peer_addr",
+ unix_addr(aad(sa)->net.addr),
+ aad(sa)->net.addrlen);
+ else
+ audit_unix_sk_addr(ab, "peer_addr",
+ aad(sa)->net.peer_sk);
+ }
+ }
if (aad(sa)->peer) {
audit_log_format(ab, " peer=");
aa_label_xaudit(ab, labels_ns(aad(sa)->label), aad(sa)->peer,
@@ -200,5 +249,7 @@ int aa_sock_file_perm(struct aa_label *label, const char *op, u32 request,
AA_BUG(!sock);
AA_BUG(!sock->sk);
- return aa_label_sk_perm(label, op, request, sock->sk);
+ return af_select(sock->sk->sk_family,
+ file_perm(label, op, request, sock),
+ aa_label_sk_perm(label, op, request, sock->sk));
}
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