Remove kdbus Linux Security Module hooks

This commit removes support for kdbus-LSM hooks as policy decisions
are handled solely by userspace (libdbuspolicy library).  This commit
reverts following:

 - 802de9506 ("lsm: smack: smack callbacks for kdbus security hooks")

 - f13b7e7bd ("kdbus: use LSM hooks in kdbus code")

 - 067afa709 ("lsm: smack: Make ipc/kdbus includes visible so smack callbacks could see them")

 - 442f047fd ("lsm: make security_file_receive available for external modules")

 - 3b556db4b ("lsm: kdbus security hooks")

Change-Id: Iae90cdb9577a9e706288b28d70bd57574398276e
Signed-off-by: Karol Lewandowski <k.lewandowsk@samsung.com>
Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>

diff --git a/include/linux/security.h b/include/linux/security.h
index bf6e5dc..18264ea 100644 (file)
--- a/include/linux/security.h
+++ b/include/linux/security.h
@@ -53,7 +53,6 @@ struct msg_queue;
 struct xattr;
 struct xfrm_sec_ctx;
 struct mm_struct;
-struct kdbus_conn;
 
 /* Maximum number of letters for an LSM name string */
 #define SECURITY_NAME_MAX      10
@@ -1456,20 +1455,6 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
  *     @inode we wish to get the security context of.
  *     @ctx is a pointer in which to place the allocated security context.
  *     @ctxlen points to the place to put the length of @ctx.
- *
- * Security hooks for kdbus
- *
- * @kdbus_conn_alloc:
- *     Allocate and initialize security related part of kdbus connection.
- *     Return 0 on success.
- *
- * @kdbus_conn_free:
- *     Deallocate security related part of kdbus connection.
- *
- * @kdbus_talk:
- *     Check if peers can talk to each other.
- *     Return 0 if permission is granted.
- *
  * This is the main security structure.
  */
 struct security_operations {
@@ -1687,13 +1672,6 @@ struct security_operations {
        int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen);
        int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen);
 
-#ifdef CONFIG_KDBUS
-       int (*kdbus_conn_alloc)(struct kdbus_conn *conn);
-       void (*kdbus_conn_free)(struct kdbus_conn *conn);
-       int (*kdbus_talk)(const struct kdbus_conn *src,
-                         const struct kdbus_conn *dst);
-#endif /* CONFIG_KDBUS */
-
 #ifdef CONFIG_SECURITY_NETWORK
        int (*unix_stream_connect) (struct sock *sock, struct sock *other, struct sock *newsk);
        int (*unix_may_send) (struct socket *sock, struct socket *other);
@@ -3116,34 +3094,6 @@ static inline int security_path_chroot(struct path *path)
 }
 #endif /* CONFIG_SECURITY_PATH */
 
-#ifdef CONFIG_KDBUS
-#ifdef CONFIG_SECURITY
-
-int security_kdbus_conn_alloc(struct kdbus_conn *conn);
-void security_kdbus_conn_free(struct kdbus_conn *conn);
-int security_kdbus_talk(const struct kdbus_conn *src,
-                       const struct kdbus_conn *dst);
-
-#else /* CONFIG_SECURITY */
-
-static inline int security_kdbus_conn_alloc(struct kdbus_conn *conn)
-{
-       return 0;
-}
-
-static inline void security_kdbus_conn_free(struct kdbus_conn *conn)
-{
-}
-
-static inline int security_kdbus_talk(const struct kdbus_conn *src,
-                                     const struct kdbus_conn *dst)
-{
-       return 0;
-}
-
-#endif /* CONFIG_SECURITY */
-#endif /* CONFIG_KDBUS */
-
 #ifdef CONFIG_KEYS
 #ifdef CONFIG_SECURITY
 

diff --git a/ipc/kdbus/connection.c b/ipc/kdbus/connection.c
index 8800077..02a6872 100644 (file)
--- a/ipc/kdbus/connection.c
+++ b/ipc/kdbus/connection.c
@@ -31,7 +31,6 @@
 #include <linux/slab.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
-#include <linux/security.h>
 
 #include "bus.h"
 #include "connection.h"
@@ -54,7 +53,7 @@
 #define KDBUS_CONN_ACTIVE_NEW  (INT_MIN + 1)
 
 /* Disable internal kdbus policy - possibilities of connections to own, see and
- * talk to names are restricted by libdbuspolicy library and LSM hooks
+ * talk to names are restricted by libdbuspolicy library
  */
 #define DISABLE_KDBUS_POLICY
 
@@ -228,10 +227,6 @@ static struct kdbus_conn *kdbus_conn_new(struct kdbus_ep *ep, bool privileged,
                }
        }
 
-       ret = security_kdbus_conn_alloc(conn);
-       if (ret)
-               goto exit_unref;
-
        if (atomic_inc_return(&conn->user->connections) > KDBUS_USER_MAX_CONN) {
                /* decremented by destructor as conn->user is valid */
                ret = -EMFILE;
@@ -286,7 +281,6 @@ static void __kdbus_conn_free(struct kref *kref)
        kdbus_pool_free(conn->pool);
        kdbus_ep_unref(conn->ep);
        put_cred(conn->cred);
-       security_kdbus_conn_free(conn);
        kfree(conn->description);
        kfree(conn->quota);
        kfree(conn);
@@ -1126,10 +1120,6 @@ static int kdbus_conn_reply(struct kdbus_conn *src, struct kdbus_kmsg *kmsg)
        if (ret < 0)
                goto exit;
 
-       ret = security_kdbus_talk(src, dst);
-       if (ret)
-               goto exit;
-
        mutex_lock(&dst->lock);
        reply = kdbus_reply_find(src, dst, kmsg->msg.cookie_reply);
        if (reply) {
@@ -1219,12 +1209,8 @@ static struct kdbus_reply *kdbus_conn_call(struct kdbus_conn *src,
        if (ret < 0)
                goto exit;
 
-       ret = security_kdbus_talk(src, dst);
-       if (ret)
-               goto exit;
-
        /* Disable internal kdbus policy - possibilities of connections to own,
-        * see and talk to well-known names are restricted by LSM hooks
+        * see and talk to well-known names are restricted by libdbuspolicy
        if (!kdbus_conn_policy_talk(src, current_cred(), dst)) {
                ret = -EPERM;
                goto exit;
@@ -1296,10 +1282,6 @@ static int kdbus_conn_unicast(struct kdbus_conn *src, struct kdbus_kmsg *kmsg)
        if (ret < 0)
                goto exit;
 
-       ret = security_kdbus_talk(src, dst);
-       if (ret)
-               goto exit;
-
        if (is_signal) {
                /* like broadcasts we eavesdrop even if the msg is dropped */
                kdbus_bus_eavesdrop(bus, src, kmsg);
@@ -1308,12 +1290,9 @@ static int kdbus_conn_unicast(struct kdbus_conn *src, struct kdbus_kmsg *kmsg)
                if (!kdbus_match_db_match_kmsg(dst->match_db, src, kmsg) ||
                    !kdbus_conn_policy_talk(dst, NULL, src))
                        goto exit;
-        /* Disable internal kdbus policy - possibilities of connections to own,
-         * see and talk to well-known names are restricted by LSM hooks
        } else if (!kdbus_conn_policy_talk(src, current_cred(), dst)) {
                ret = -EPERM;
                goto exit;
-       */
        } else if (kmsg->msg.flags & KDBUS_MSG_EXPECT_REPLY) {
                wait = kdbus_reply_new(dst, src, &kmsg->msg, name, false);
                if (IS_ERR(wait)) {

diff --git a/ipc/kdbus/connection.h b/ipc/kdbus/connection.h
index 4a5c120..d1ffe90 100644 (file)
--- a/ipc/kdbus/connection.h
+++ b/ipc/kdbus/connection.h
@@ -73,7 +73,6 @@ struct kdbus_kmsg;
  * @names_queue_list:  Well-known names this connection waits for
  * @privileged:                Whether this connection is privileged on the bus
  * @faked_meta:                Whether the metadata was faked on HELLO
- * @security:          LSM security blob
  */
 struct kdbus_conn {
        struct kref kref;
@@ -114,10 +113,6 @@ struct kdbus_conn {
 
        bool privileged:1;
        bool faked_meta:1;
-
-#ifdef CONFIG_SECURITY
-       void *security;
-#endif
 };
 
 struct kdbus_conn *kdbus_conn_ref(struct kdbus_conn *conn);

diff --git a/ipc/kdbus/names.c b/ipc/kdbus/names.c
index 90e0c01..df99e4d 100644 (file)
--- a/ipc/kdbus/names.c
+++ b/ipc/kdbus/names.c
@@ -290,13 +290,10 @@ int kdbus_name_acquire(struct kdbus_name_registry *reg,
 
        down_write(&reg->rwlock);
 
-        /* Disable internal kdbus policy - possibilities of connections to own,
-         * see and talk to well-known names are restricted by LSM hooks
        if (!kdbus_conn_policy_own_name(conn, current_cred(), name)) {
                ret = -EPERM;
                goto exit_unlock;
        }
-       */
 
        hash = kdbus_strhash(name);
        e = kdbus_name_find(reg, hash, name);

diff --git a/ipc/kdbus/queue.c b/ipc/kdbus/queue.c
index e04aee6..a449464 100644 (file)
--- a/ipc/kdbus/queue.c
+++ b/ipc/kdbus/queue.c
@@ -28,7 +28,6 @@
 #include <linux/slab.h>
 #include <linux/syscalls.h>
 #include <linux/uio.h>
-#include <linux/security.h>
 
 #include "util.h"
 #include "domain.h"
@@ -515,17 +514,12 @@ int kdbus_queue_entry_install(struct kdbus_queue_entry *entry,
 
                for (i = 0; i < res->fds_count; i++) {
                        if (install_fds) {
-                               if (security_file_receive(res->fds[i])) {
-                                       fds[i] = -1;
+                               fds[i] = get_unused_fd_flags(O_CLOEXEC);
+                               if (fds[i] >= 0)
+                                       fd_install(fds[i],
+                                                  get_file(res->fds[i]));
+                               else
                                        incomplete_fds = true;
-                               } else {
-                                       fds[i] = get_unused_fd_flags(O_CLOEXEC);
-                                       if (fds[i] >= 0)
-                                               fd_install(fds[i],
-                                                       get_file(res->fds[i]));
-                                       else
-                                               incomplete_fds = true;
-                               }
                        } else {
                                fds[i] = -1;
                        }
@@ -563,17 +557,13 @@ int kdbus_queue_entry_install(struct kdbus_queue_entry *entry,
                m.fd = -1;
 
                if (install_fds) {
-                       if (security_file_receive(d->memfd.file)) {
+                       m.fd = get_unused_fd_flags(O_CLOEXEC);
+                       if (m.fd < 0) {
+                               m.fd = -1;
                                incomplete_fds = true;
                        } else {
-                               m.fd = get_unused_fd_flags(O_CLOEXEC);
-                               if (m.fd < 0) {
-                                       m.fd = -1;
-                                       incomplete_fds = true;
-                               } else {
-                                       fd_install(m.fd,
-                                               get_file(d->memfd.file));
-                               }
+                               fd_install(m.fd,
+                                          get_file(d->memfd.file));
                        }
                }
 

diff --git a/security/capability.c b/security/capability.c
index 4b01edd..0d03fcc 100644 (file)
--- a/security/capability.c
+++ b/security/capability.c
@@ -595,25 +595,6 @@ static int cap_sem_semop(struct sem_array *sma, struct sembuf *sops,
        return 0;
 }
 
-#ifdef CONFIG_KDBUS
-
-static int cap_kdbus_conn_alloc(struct kdbus_conn *conn)
-{
-       return 0;
-}
-
-static void cap_kdbus_conn_free(struct kdbus_conn *conn)
-{
-}
-
-static int cap_kdbus_talk(const struct kdbus_conn *src,
-                         const struct kdbus_conn *dst)
-{
-       return 0;
-}
-
-#endif /* CONFIG_KDBUS */
-
 #ifdef CONFIG_SECURITY_NETWORK
 static int cap_unix_stream_connect(struct sock *sock, struct sock *other,
                                   struct sock *newsk)
@@ -1111,11 +1092,6 @@ void __init security_fixup_ops(struct security_operations *ops)
        set_to_cap_if_null(ops, inode_notifysecctx);
        set_to_cap_if_null(ops, inode_setsecctx);
        set_to_cap_if_null(ops, inode_getsecctx);
-#ifdef CONFIG_KDBUS
-       set_to_cap_if_null(ops, kdbus_conn_alloc);
-       set_to_cap_if_null(ops, kdbus_conn_free);
-       set_to_cap_if_null(ops, kdbus_talk);
-#endif /* CONFIG_KDBUS */
 #ifdef CONFIG_SECURITY_NETWORK
        set_to_cap_if_null(ops, unix_stream_connect);
        set_to_cap_if_null(ops, unix_may_send);

diff --git a/security/security.c b/security/security.c
index f244302..8e9b1f4 100644 (file)
--- a/security/security.c
+++ b/security/security.c
@@ -812,7 +812,6 @@ int security_file_receive(struct file *file)
 {
        return security_ops->file_receive(file);
 }
-EXPORT_SYMBOL(security_file_receive);
 
 int security_file_open(struct file *file, const struct cred *cred)
 {
@@ -1153,29 +1152,6 @@ int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
 }
 EXPORT_SYMBOL(security_inode_getsecctx);
 
-#ifdef CONFIG_KDBUS
-
-int security_kdbus_conn_alloc(struct kdbus_conn *conn)
-{
-       return security_ops->kdbus_conn_alloc(conn);
-}
-EXPORT_SYMBOL(security_kdbus_conn_alloc);
-
-void security_kdbus_conn_free(struct kdbus_conn *conn)
-{
-       security_ops->kdbus_conn_free(conn);
-}
-EXPORT_SYMBOL(security_kdbus_conn_free);
-
-int security_kdbus_talk(const struct kdbus_conn *src,
-                       const struct kdbus_conn *dst)
-{
-       return security_ops->kdbus_talk(src, dst);
-}
-EXPORT_SYMBOL(security_kdbus_talk);
-
-#endif /* CONFIG_KDBUS */
-
 #ifdef CONFIG_SECURITY_NETWORK
 
 int security_unix_stream_connect(struct sock *sock, struct sock *other, struct sock *newsk)

diff --git a/security/smack/Makefile b/security/smack/Makefile
index bd6927c..ee2ebd5 100644 (file)
--- a/security/smack/Makefile
+++ b/security/smack/Makefile
@@ -6,5 +6,3 @@ obj-$(CONFIG_SECURITY_SMACK) := smack.o
 
 smack-y := smack_lsm.o smack_access.o smackfs.o
 smack-$(CONFIG_SECURITY_SMACK_NETFILTER) += smack_netfilter.o
-
-ccflags-y += -Iipc

diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c
index e111490..793c23a 100644 (file)
--- a/security/smack/smack_lsm.c
+++ b/security/smack/smack_lsm.c
@@ -42,7 +42,6 @@
 #include <linux/shm.h>
 #include <linux/binfmts.h>
 #include <linux/parser.h>
-#include <kdbus/connection.h>
 #include "smack.h"
 
 #define TRANS_TRUE     "TRUE"
@@ -3616,60 +3615,6 @@ static int smack_setprocattr(struct task_struct *p, char *name,
        return size;
 }
 
-#ifdef CONFIG_KDBUS
-
-/**
- * smack_kdbus_conn_alloc - Set the security blob for a KDBus connection
- * @conn: the connection
- *
- * Returns 0
- */
-static int smack_kdbus_conn_alloc(struct kdbus_conn *conn)
-{
-       conn->security = smk_of_current();
-
-       return 0;
-}
-
-/**
- * smack_kdbus_conn_free - Clear the security blob for a KDBus connection
- * @conn: the connection
- *
- * Clears the blob pointer
- */
-static void smack_kdbus_conn_free(struct kdbus_conn *conn)
-{
-       conn->security = NULL;
-}
-
-/**
- * smack_kdbus_talk - Smack access on KDBus
- * @src: source kdbus connection
- * @dst: destination kdbus connection
- *
- * Return 0 if a subject with the smack of sock could access
- * an object with the smack of other, otherwise an error code
- */
-static int smack_kdbus_talk(const struct kdbus_conn *src,
-                           const struct kdbus_conn *dst)
-{
-       struct smk_audit_info ad;
-       struct smack_known *sskp = src->security;
-       struct smack_known *dskp = dst->security;
-       int rc;
-
-       if (smack_privileged(CAP_MAC_OVERRIDE))
-               return 0;
-
-       smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_NONE);
-
-       rc = smk_access(sskp, dskp, MAY_WRITE, &ad);
-       rc = smk_bu_note("kdbus talk", sskp, dskp, MAY_WRITE, rc);
-       return rc;
-}
-
-#endif /* CONFIG_KDBUS */
-
 /**
  * smack_unix_stream_connect - Smack access on UDS
  * @sock: one sock
@@ -4691,12 +4636,6 @@ struct security_operations smack_ops = {
        .getprocattr =                  smack_getprocattr,
        .setprocattr =                  smack_setprocattr,
 
-#ifdef CONFIG_KDBUS
-       .kdbus_conn_alloc =             smack_kdbus_conn_alloc,
-       .kdbus_conn_free =              smack_kdbus_conn_free,
-       .kdbus_talk =                   smack_kdbus_talk,
-#endif
-
        .unix_stream_connect =          smack_unix_stream_connect,
        .unix_may_send =                smack_unix_may_send,