AppArmor: Move path failure information into aa_get_name and rename

Move the path name lookup failure messages into the main path name lookup
routine, as the information is useful in more than just aa_path_perm.

Also rename aa_get_name to aa_path_name as it is not getting a reference
counted object with a corresponding put fn.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>

diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c
index c1e18ba..7c69599 100644 (file)
--- a/security/apparmor/domain.c
+++ b/security/apparmor/domain.c
@@ -372,13 +372,12 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm)
        state = profile->file.start;
 
        /* buffer freed below, name is pointer into buffer */
-       error = aa_get_name(&bprm->file->f_path, profile->path_flags, &buffer,
-                           &name);
+       error = aa_path_name(&bprm->file->f_path, profile->path_flags, &buffer,
+                            &name, &info);
        if (error) {
                if (profile->flags &
                    (PFLAG_IX_ON_NAME_ERROR | PFLAG_UNCONFINED))
                        error = 0;
-               info = "Exec failed name resolution";
                name = bprm->filename;
                goto audit;
        }

diff --git a/security/apparmor/file.c b/security/apparmor/file.c
index bba875c..3022c0f 100644 (file)
--- a/security/apparmor/file.c
+++ b/security/apparmor/file.c
@@ -278,22 +278,16 @@ int aa_path_perm(int op, struct aa_profile *profile, struct path *path,
        int error;
 
        flags |= profile->path_flags | (S_ISDIR(cond->mode) ? PATH_IS_DIR : 0);
-       error = aa_get_name(path, flags, &buffer, &name);
+       error = aa_path_name(path, flags, &buffer, &name, &info);
        if (error) {
                if (error == -ENOENT && is_deleted(path->dentry)) {
                        /* Access to open files that are deleted are
                         * give a pass (implicit delegation)
                         */
                        error = 0;
+                       info = NULL;
                        perms.allow = request;
-               } else if (error == -ENOENT)
-                       info = "Failed name lookup - deleted entry";
-               else if (error == -ESTALE)
-                       info = "Failed name lookup - disconnected path";
-               else if (error == -ENAMETOOLONG)
-                       info = "Failed name lookup - name too long";
-               else
-                       info = "Failed name lookup";
+               }
        } else {
                aa_str_perms(profile->file.dfa, profile->file.start, name, cond,
                             &perms);
@@ -364,12 +358,14 @@ int aa_path_link(struct aa_profile *profile, struct dentry *old_dentry,
        lperms = nullperms;
 
        /* buffer freed below, lname is pointer in buffer */
-       error = aa_get_name(&link, profile->path_flags, &buffer, &lname);
+       error = aa_path_name(&link, profile->path_flags, &buffer, &lname,
+                            &info);
        if (error)
                goto audit;
 
        /* buffer2 freed below, tname is pointer in buffer2 */
-       error = aa_get_name(&target, profile->path_flags, &buffer2, &tname);
+       error = aa_path_name(&target, profile->path_flags, &buffer2, &tname,
+                            &info);
        if (error)
                goto audit;
 

diff --git a/security/apparmor/include/path.h b/security/apparmor/include/path.h
index 27b327a..286ac75 100644 (file)
--- a/security/apparmor/include/path.h
+++ b/security/apparmor/include/path.h
@@ -26,6 +26,7 @@ enum path_flags {
        PATH_MEDIATE_DELETED = 0x10000, /* mediate deleted paths */
 };
 
-int aa_get_name(struct path *path, int flags, char **buffer, const char **name);
+int aa_path_name(struct path *path, int flags, char **buffer,
+                const char **name, const char **info);
 
 #endif /* __AA_PATH_H */

diff --git a/security/apparmor/path.c b/security/apparmor/path.c
index a7936df..2daeea4 100644 (file)
--- a/security/apparmor/path.c
+++ b/security/apparmor/path.c
@@ -157,7 +157,7 @@ out:
  * Returns: %0 else error on failure
  */
 static int get_name_to_buffer(struct path *path, int flags, char *buffer,
-                             int size, char **name)
+                             int size, char **name, const char **info)
 {
        int adjust = (flags & PATH_IS_DIR) ? 1 : 0;
        int error = d_namespace_path(path, buffer, size - adjust, name, flags);
@@ -169,15 +169,27 @@ static int get_name_to_buffer(struct path *path, int flags, char *buffer,
                 */
                strcpy(&buffer[size - 2], "/");
 
+       if (info && error) {
+               if (error == -ENOENT)
+                       *info = "Failed name lookup - deleted entry";
+               else if (error == -ESTALE)
+                       *info = "Failed name lookup - disconnected path";
+               else if (error == -ENAMETOOLONG)
+                       *info = "Failed name lookup - name too long";
+               else
+                       *info = "Failed name lookup";
+       }
+
        return error;
 }
 
 /**
- * aa_get_name - compute the pathname of a file
+ * aa_path_name - compute the pathname of a file
  * @path: path the file  (NOT NULL)
  * @flags: flags controlling path name generation
  * @buffer: buffer that aa_get_name() allocated  (NOT NULL)
  * @name: Returns - the generated path name if !error (NOT NULL)
+ * @info: Returns - information on why the path lookup failed (MAYBE NULL)
  *
  * @name is a pointer to the beginning of the pathname (which usually differs
  * from the beginning of the buffer), or NULL.  If there is an error @name
@@ -190,7 +202,8 @@ static int get_name_to_buffer(struct path *path, int flags, char *buffer,
  *
  * Returns: %0 else error code if could retrieve name
  */
-int aa_get_name(struct path *path, int flags, char **buffer, const char **name)
+int aa_path_name(struct path *path, int flags, char **buffer, const char **name,
+                const char **info)
 {
        char *buf, *str = NULL;
        int size = 256;
@@ -204,7 +217,7 @@ int aa_get_name(struct path *path, int flags, char **buffer, const char **name)
                if (!buf)
                        return -ENOMEM;
 
-               error = get_name_to_buffer(path, flags, buf, size, &str);
+               error = get_name_to_buffer(path, flags, buf, size, &str, info);
                if (error != -ENAMETOOLONG)
                        break;
 
@@ -212,6 +225,7 @@ int aa_get_name(struct path *path, int flags, char **buffer, const char **name)
                size <<= 1;
                if (size > aa_g_path_max)
                        return -ENAMETOOLONG;
+               *info = NULL;
        }
        *buffer = buf;
        *name = str;