Merge tag 'v3.4.109' into mm-6.0

Change-Id: I93b29443377e338fc5d3b031b130da720f788879
Signed-off-by: José Adolfo Galdámez <josegalre@pac-rom.com>
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index cf6e7f4..f4576dc 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -5939,12 +5939,11 @@
 		return -ENOSPC;
 	}
 
-	if (btrfs_test_opt(root, DISCARD))
-		ret = btrfs_discard_extent(root, start, len, NULL);
-
 	if (pin)
 		pin_down_extent(root, cache, start, len, 1);
 	else {
+		if (btrfs_test_opt(root, DISCARD))
+			ret = btrfs_discard_extent(root, start, len, NULL);
 		btrfs_add_free_space(cache, start, len);
 		btrfs_update_reserved_bytes(cache, len, RESERVE_FREE);
 	}
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 3a65f43..d46c481 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -2374,6 +2374,11 @@
 	if (off + len == src->i_size)
 		len = ALIGN(src->i_size, bs) - off;
 
+	if (len == 0) {
+		ret = 0;
+		goto out_unlock;
+	}
+
 	/* verify the end result is block aligned */
 	if (!IS_ALIGNED(off, bs) || !IS_ALIGNED(off + len, bs) ||
 	    !IS_ALIGNED(destoff, bs))
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index e7a5659..0ee73d1 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -310,21 +310,40 @@
 /*
  * Check if the attribute is in a supported namespace.
  *
- * This applied after the check for the synthetic attributes in the system
+ * This is applied after the check for the synthetic attributes in the system
  * namespace.
  */
-static bool btrfs_is_valid_xattr(const char *name)
+static int btrfs_is_valid_xattr(const char *name)
 {
-	return !strncmp(name, XATTR_SECURITY_PREFIX,
-			XATTR_SECURITY_PREFIX_LEN) ||
-	       !strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN) ||
-	       !strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN) ||
-	       !strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN);
+	int len = strlen(name);
+	int prefixlen = 0;
+
+	if (!strncmp(name, XATTR_SECURITY_PREFIX,
+			XATTR_SECURITY_PREFIX_LEN))
+		prefixlen = XATTR_SECURITY_PREFIX_LEN;
+	else if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
+		prefixlen = XATTR_SYSTEM_PREFIX_LEN;
+	else if (!strncmp(name, XATTR_TRUSTED_PREFIX, XATTR_TRUSTED_PREFIX_LEN))
+		prefixlen = XATTR_TRUSTED_PREFIX_LEN;
+	else if (!strncmp(name, XATTR_USER_PREFIX, XATTR_USER_PREFIX_LEN))
+		prefixlen = XATTR_USER_PREFIX_LEN;
+	else
+		return -EOPNOTSUPP;
+
+	/*
+	 * The name cannot consist of just prefix
+	 */
+	if (len <= prefixlen)
+		return -EINVAL;
+
+	return 0;
 }
 
 ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
 		       void *buffer, size_t size)
 {
+	int ret;
+
 	/*
 	 * If this is a request for a synthetic attribute in the system.*
 	 * namespace use the generic infrastructure to resolve a handler
@@ -333,8 +352,9 @@
 	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 		return generic_getxattr(dentry, name, buffer, size);
 
-	if (!btrfs_is_valid_xattr(name))
-		return -EOPNOTSUPP;
+	ret = btrfs_is_valid_xattr(name);
+	if (ret)
+		return ret;
 	return __btrfs_getxattr(dentry->d_inode, name, buffer, size);
 }
 
@@ -342,6 +362,7 @@
 		   size_t size, int flags)
 {
 	struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+	int ret;
 
 	/*
 	 * The permission on security.* and system.* is not checked
@@ -358,8 +379,9 @@
 	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 		return generic_setxattr(dentry, name, value, size, flags);
 
-	if (!btrfs_is_valid_xattr(name))
-		return -EOPNOTSUPP;
+	ret = btrfs_is_valid_xattr(name);
+	if (ret)
+		return ret;
 
 	if (size == 0)
 		value = "";  /* empty EA, do not remove */
@@ -371,6 +393,7 @@
 int btrfs_removexattr(struct dentry *dentry, const char *name)
 {
 	struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+	int ret;
 
 	/*
 	 * The permission on security.* and system.* is not checked
@@ -387,8 +410,9 @@
 	if (!strncmp(name, XATTR_SYSTEM_PREFIX, XATTR_SYSTEM_PREFIX_LEN))
 		return generic_removexattr(dentry, name);
 
-	if (!btrfs_is_valid_xattr(name))
-		return -EOPNOTSUPP;
+	ret = btrfs_is_valid_xattr(name);
+	if (ret)
+		return ret;
 
 	return __btrfs_setxattr(NULL, dentry->d_inode, name, NULL, 0,
 				XATTR_REPLACE);