1 files changed, 70 insertions, 64 deletions

diff --git a/security/apparmor/path.c b/security/apparmor/path.c
index 19358dc1460..35b394a75d7 100644
--- a/security/apparmor/path.c
+++ b/security/apparmor/path.c
@@ -13,7 +13,6 @@
  */
 
 #include <linux/magic.h>
-#include <linux/mnt_namespace.h>
 #include <linux/mount.h>
 #include <linux/namei.h>
 #include <linux/nsproxy.h>
@@ -57,68 +56,71 @@ static int prepend(char **buffer, int buflen, const char *str, int namelen)
 static int d_namespace_path(struct path *path, char *buf, int buflen,
 			    char **name, int flags)
 {
-	struct path root, tmp;
 	char *res;
-	int deleted, connected;
 	int error = 0;
+	int connected = 1;
+
+	if (path->mnt->mnt_flags & MNT_INTERNAL) {
+		/* it's not mounted anywhere */
+		res = dentry_path(path->dentry, buf, buflen);
+		*name = res;
+		if (IS_ERR(res)) {
+			*name = buf;
+			return PTR_ERR(res);
+		}
+		if (path->dentry->d_sb->s_magic == PROC_SUPER_MAGIC &&
+		    strncmp(*name, "/sys/", 5) == 0) {
+			/* TODO: convert over to using a per namespace
+			 * control instead of hard coded /proc
+			 */
+			return prepend(name, *name - buf, "/proc", 5);
+		}
+		return 0;
+	}
 
-	/* Get the root we want to resolve too, released below */
+	/* resolve paths relative to chroot?*/
 	if (flags & PATH_CHROOT_REL) {
-		/* resolve paths relative to chroot */
+		struct path root;
 		get_fs_root(current->fs, &root);
+		res = __d_path(path, &root, buf, buflen);
+		path_put(&root);
 	} else {
-		/* resolve paths relative to namespace */
-		root.mnt = current->nsproxy->mnt_ns->root;
-		root.dentry = root.mnt->mnt_root;
-		path_get(&root);
+		res = d_absolute_path(path, buf, buflen);
+		if (!our_mnt(path->mnt))
+			connected = 0;
 	}
 
-	spin_lock(&dcache_lock);
-	/* There is a race window between path lookup here and the
-	 * need to strip the " (deleted) string that __d_path applies
-	 * Detect the race and relookup the path
-	 *
-	 * The stripping of (deleted) is a hack that could be removed
-	 * with an updated __d_path
-	 */
-	do {
-		tmp = root;
-		deleted = d_unlinked(path->dentry);
-		res = __d_path(path, &tmp, buf, buflen);
-
-	} while (deleted != d_unlinked(path->dentry));
-	spin_unlock(&dcache_lock);
-
-	*name = res;
 	/* handle error conditions - and still allow a partial path to
 	 * be returned.
 	 */
-	if (IS_ERR(res)) {
-		error = PTR_ERR(res);
-		*name = buf;
-		goto out;
-	}
-	if (deleted) {
-		/* On some filesystems, newly allocated dentries appear to the
-		 * security_path hooks as a deleted dentry except without an
-		 * inode allocated.
-		 *
-		 * Remove the appended deleted text and return as string for
-		 * normal mediation, or auditing.  The (deleted) string is
-		 * guaranteed to be added in this case, so just strip it.
-		 */
-		buf[buflen - 11] = 0;	/* - (len(" (deleted)") +\0) */
+	if (!res || IS_ERR(res)) {
+		if (PTR_ERR(res) == -ENAMETOOLONG)
+			return -ENAMETOOLONG;
+		connected = 0;
+		res = dentry_path_raw(path->dentry, buf, buflen);
+		if (IS_ERR(res)) {
+			error = PTR_ERR(res);
+			*name = buf;
+			goto out;
+		};
+	} else if (!our_mnt(path->mnt))
+		connected = 0;
+
+	*name = res;
 
-		if (path->dentry->d_inode && !(flags & PATH_MEDIATE_DELETED)) {
+	/* Handle two cases:
+	 * 1. A deleted dentry && profile is not allowing mediation of deleted
+	 * 2. On some filesystems, newly allocated dentries appear to the
+	 *    security_path hooks as a deleted dentry except without an inode
+	 *    allocated.
+	 */
+	if (d_unlinked(path->dentry) && path->dentry->d_inode &&
+	    !(flags & PATH_MEDIATE_DELETED)) {
 			error = -ENOENT;
 			goto out;
-		}
 	}
 
-	/* Determine if the path is connected to the expected root */
-	connected = tmp.dentry == root.dentry && tmp.mnt == root.mnt;
-
-	/* If the path is not connected,
+	/* If the path is not connected to the expected root,
 	 * check if it is a sysctl and handle specially else remove any
 	 * leading / that __d_path may have returned.
 	 * Unless
@@ -130,29 +132,19 @@ static int d_namespace_path(struct path *path, char *buf, int buflen,
 	 *     namespace root.
 	 */
 	if (!connected) {
-		/* is the disconnect path a sysctl? */
-		if (tmp.dentry->d_sb->s_magic == PROC_SUPER_MAGIC &&
-		    strncmp(*name, "/sys/", 5) == 0) {
-			/* TODO: convert over to using a per namespace
-			 * control instead of hard coded /proc
-			 */
-			error = prepend(name, *name - buf, "/proc", 5);
-		} else if (!(flags & PATH_CONNECT_PATH) &&
+		if (!(flags & PATH_CONNECT_PATH) &&
 			   !(((flags & CHROOT_NSCONNECT) == CHROOT_NSCONNECT) &&
-			     (tmp.mnt == current->nsproxy->mnt_ns->root &&
-			      tmp.dentry == tmp.mnt->mnt_root))) {
+			     our_mnt(path->mnt))) {
 			/* disconnected path, don't return pathname starting
 			 * with '/'
 			 */
-			error = -ESTALE;
+			error = -EACCES;
 			if (*res == '/')
 				*name = res + 1;
 		}
 	}
 
 out:
-	path_put(&root);
-
 	return error;
 }
 
@@ -167,7 +159,7 @@ 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);
@@ -179,15 +171,27 @@ 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 == -EACCES)
+			*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
@@ -200,7 +204,8 @@ 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;
@@ -214,7 +219,7 @@ 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;
 
@@ -222,6 +227,7 @@ 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;