Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security

Pull security layer updates from James Morris:

 - a major update for AppArmor. From JJ:

     * several bug fixes and cleanups

     * the patch to add symlink support to securityfs that was floated
       on the list earlier and the apparmorfs changes that make use of
       securityfs symlinks

     * it introduces the domain labeling base code that Ubuntu has been
       carrying for several years, with several cleanups applied. And it
       converts the current mediation over to using the domain labeling
       base, which brings domain stacking support with it. This finally
       will bring the base upstream code in line with Ubuntu and provide
       a base to upstream the new feature work that Ubuntu carries.

     * This does _not_ contain any of the newer apparmor mediation
       features/controls (mount, signals, network, keys, ...) that
       Ubuntu is currently carrying, all of which will be RFC'd on top
       of this.

 - Notable also is the Infiniband work in SELinux, and the new file:map
   permission. From Paul:

      "While we're down to 21 patches for v4.13 (it was 31 for v4.12),
       the diffstat jumps up tremendously with over 2k of line changes.

       Almost all of these changes are the SELinux/IB work done by
       Daniel Jurgens; some other noteworthy changes include a NFS v4.2
       labeling fix, a new file:map permission, and reporting of policy
       capabilities on policy load"

   There's also now genfscon labeling support for tracefs, which was
   lost in v4.1 with the separation from debugfs.

 - Smack incorporates a safer socket check in file_receive, and adds a
   cap_capable call in privilege check.

 - TPM as usual has a bunch of fixes and enhancements.

 - Multiple calls to security_add_hooks() can now be made for the same
   LSM, to allow LSMs to have hook declarations across multiple files.

 - IMA now supports different "ima_appraise=" modes (eg. log, fix) from
   the boot command line.

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (126 commits)
  apparmor: put back designators in struct initialisers
  seccomp: Switch from atomic_t to recount_t
  seccomp: Adjust selftests to avoid double-join
  seccomp: Clean up core dump logic
  IMA: update IMA policy documentation to include pcr= option
  ima: Log the same audit cause whenever a file has no signature
  ima: Simplify policy_func_show.
  integrity: Small code improvements
  ima: fix get_binary_runtime_size()
  ima: use ima_parse_buf() to parse template data
  ima: use ima_parse_buf() to parse measurements headers
  ima: introduce ima_parse_buf()
  ima: Add cgroups2 to the defaults list
  ima: use memdup_user_nul
  ima: fix up #endif comments
  IMA: Correct Kconfig dependencies for hash selection
  ima: define is_ima_appraise_enabled()
  ima: define Kconfig IMA_APPRAISE_BOOTPARAM option
  ima: define a set of appraisal rules requiring file signatures
  ima: extend the "ima_policy" boot command line to support multiple policies
  ...

1 files changed, 52 insertions, 78 deletions

diff --git a/security/apparmor/path.c b/security/apparmor/path.c
index a8fc7d08c144..9d5de1d05be4 100644
--- a/security/apparmor/path.c
+++ b/security/apparmor/path.c
@@ -50,7 +50,7 @@ static int prepend(char **buffer, int buflen, const char *str, int namelen)
  *     namespace root.
  */
 static int disconnect(const struct path *path, char *buf, char **name,
-		      int flags)
+		      int flags, const char *disconnected)
 {
 	int error = 0;
 
@@ -63,9 +63,14 @@ static int disconnect(const struct path *path, char *buf, char **name,
 		error = -EACCES;
 		if (**name == '/')
 			*name = *name + 1;
-	} else if (**name != '/')
-		/* CONNECT_PATH with missing root */
-		error = prepend(name, *name - buf, "/", 1);
+	} else {
+		if (**name != '/')
+			/* CONNECT_PATH with missing root */
+			error = prepend(name, *name - buf, "/", 1);
+		if (!error && disconnected)
+			error = prepend(name, *name - buf, disconnected,
+					strlen(disconnected));
+	}
 
 	return error;
 }
@@ -74,9 +79,9 @@ static int disconnect(const struct path *path, char *buf, char **name,
  * d_namespace_path - lookup a name associated with a given path
  * @path: path to lookup  (NOT NULL)
  * @buf:  buffer to store path to  (NOT NULL)
- * @buflen: length of @buf
  * @name: Returns - pointer for start of path name with in @buf (NOT NULL)
  * @flags: flags controlling path lookup
+ * @disconnected: string to prefix to disconnected paths
  *
  * Handle path name lookup.
  *
@@ -84,12 +89,14 @@ static int disconnect(const struct path *path, char *buf, char **name,
  *          When no error the path name is returned in @name which points to
  *          to a position in @buf
  */
-static int d_namespace_path(const struct path *path, char *buf, int buflen,
-			    char **name, int flags)
+static int d_namespace_path(const struct path *path, char *buf, char **name,
+			    int flags, const char *disconnected)
 {
 	char *res;
 	int error = 0;
 	int connected = 1;
+	int isdir = (flags & PATH_IS_DIR) ? 1 : 0;
+	int buflen = aa_g_path_max - isdir;
 
 	if (path->mnt->mnt_flags & MNT_INTERNAL) {
 		/* it's not mounted anywhere */
@@ -104,10 +111,12 @@ static int d_namespace_path(const struct path *path, char *buf, int buflen,
 			/* TODO: convert over to using a per namespace
 			 * control instead of hard coded /proc
 			 */
-			return prepend(name, *name - buf, "/proc", 5);
+			error = prepend(name, *name - buf, "/proc", 5);
+			goto out;
 		} else
-			return disconnect(path, buf, name, flags);
-		return 0;
+			error = disconnect(path, buf, name, flags,
+					   disconnected);
+		goto out;
 	}
 
 	/* resolve paths relative to chroot?*/
@@ -126,8 +135,11 @@ static int d_namespace_path(const struct path *path, char *buf, int buflen,
 	 * be returned.
 	 */
 	if (!res || IS_ERR(res)) {
-		if (PTR_ERR(res) == -ENAMETOOLONG)
-			return -ENAMETOOLONG;
+		if (PTR_ERR(res) == -ENAMETOOLONG) {
+			error = -ENAMETOOLONG;
+			*name = buf;
+			goto out;
+		}
 		connected = 0;
 		res = dentry_path_raw(path->dentry, buf, buflen);
 		if (IS_ERR(res)) {
@@ -140,6 +152,9 @@ static int d_namespace_path(const struct path *path, char *buf, int buflen,
 
 	*name = res;
 
+	if (!connected)
+		error = disconnect(path, buf, name, flags, disconnected);
+
 	/* Handle two cases:
 	 * 1. A deleted dentry && profile is not allowing mediation of deleted
 	 * 2. On some filesystems, newly allocated dentries appear to the
@@ -147,62 +162,30 @@ static int d_namespace_path(const struct path *path, char *buf, int buflen,
 	 *    allocated.
 	 */
 	if (d_unlinked(path->dentry) && d_is_positive(path->dentry) &&
-	    !(flags & PATH_MEDIATE_DELETED)) {
+	    !(flags & (PATH_MEDIATE_DELETED | PATH_DELEGATE_DELETED))) {
 			error = -ENOENT;
 			goto out;
 	}
 
-	if (!connected)
-		error = disconnect(path, buf, name, flags);
-
 out:
-	return error;
-}
-
-/**
- * get_name_to_buffer - get the pathname to a buffer ensure dir / is appended
- * @path: path to get name for  (NOT NULL)
- * @flags: flags controlling path lookup
- * @buffer: buffer to put name in  (NOT NULL)
- * @size: size of buffer
- * @name: Returns - contains position of path name in @buffer (NOT NULL)
- *
- * Returns: %0 else error on failure
- */
-static int get_name_to_buffer(const struct path *path, int flags, char *buffer,
-			      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);
-
-	if (!error && (flags & PATH_IS_DIR) && (*name)[1] != '\0')
-		/*
-		 * Append "/" to the pathname.  The root directory is a special
-		 * case; it already ends in slash.
-		 */
-		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";
-	}
+	/*
+	 * Append "/" to the pathname.  The root directory is a special
+	 * case; it already ends in slash.
+	 */
+	if (!error && isdir && ((*name)[1] != '\0' || (*name)[0] != '/'))
+		strcpy(&buf[aa_g_path_max - 2], "/");
 
 	return error;
 }
 
 /**
- * aa_path_name - compute the pathname of a file
+ * aa_path_name - get the pathname to a buffer ensure dir / is appended
  * @path: path the file  (NOT NULL)
  * @flags: flags controlling path name generation
- * @buffer: buffer that aa_get_name() allocated  (NOT NULL)
+ * @buffer: buffer to put name in (NOT NULL)
  * @name: Returns - the generated path name if !error (NOT NULL)
  * @info: Returns - information on why the path lookup failed (MAYBE NULL)
+ * @disconnected: string to prepend to disconnected paths
  *
  * @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
@@ -215,32 +198,23 @@ static int get_name_to_buffer(const struct path *path, int flags, char *buffer,
  *
  * Returns: %0 else error code if could retrieve name
  */
-int aa_path_name(const struct path *path, int flags, char **buffer,
-		 const char **name, const char **info)
+int aa_path_name(const struct path *path, int flags, char *buffer,
+		 const char **name, const char **info, const char *disconnected)
 {
-	char *buf, *str = NULL;
-	int size = 256;
-	int error;
-
-	*name = NULL;
-	*buffer = NULL;
-	for (;;) {
-		/* freed by caller */
-		buf = kmalloc(size, GFP_KERNEL);
-		if (!buf)
-			return -ENOMEM;
-
-		error = get_name_to_buffer(path, flags, buf, size, &str, info);
-		if (error != -ENAMETOOLONG)
-			break;
-
-		kfree(buf);
-		size <<= 1;
-		if (size > aa_g_path_max)
-			return -ENAMETOOLONG;
-		*info = NULL;
+	char *str = NULL;
+	int error = d_namespace_path(path, buffer, &str, flags, disconnected);
+
+	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";
 	}
-	*buffer = buf;
+
 	*name = str;
 
 	return error;