1 files changed, 103 insertions, 9 deletions

diff --git a/fs/ubifs/xattr.c b/fs/ubifs/xattr.c
index 5e0a63b1b0d5..a92be244a6fb 100644
--- a/fs/ubifs/xattr.c
+++ b/fs/ubifs/xattr.c
@@ -100,24 +100,30 @@ static const struct file_operations empty_fops;
 static int create_xattr(struct ubifs_info *c, struct inode *host,
 			const struct qstr *nm, const void *value, int size)
 {
-	int err;
+	int err, names_len;
 	struct inode *inode;
 	struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
 	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
 				.new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
 				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
 
-	if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE)
+	if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE) {
+		ubifs_err("inode %lu already has too many xattrs (%d), cannot create more",
+			  host->i_ino, host_ui->xattr_cnt);
 		return -ENOSPC;
+	}
 	/*
 	 * Linux limits the maximum size of the extended attribute names list
 	 * to %XATTR_LIST_MAX. This means we should not allow creating more
 	 * extended attributes if the name list becomes larger. This limitation
 	 * is artificial for UBIFS, though.
 	 */
-	if (host_ui->xattr_names + host_ui->xattr_cnt +
-					nm->len + 1 > XATTR_LIST_MAX)
+	names_len = host_ui->xattr_names + host_ui->xattr_cnt + nm->len + 1;
+	if (names_len > XATTR_LIST_MAX) {
+		ubifs_err("cannot add one more xattr name to inode %lu, total names length would become %d, max. is %d",
+			  host->i_ino, names_len, XATTR_LIST_MAX);
 		return -ENOSPC;
+	}
 
 	err = ubifs_budget_space(c, &req);
 	if (err)
@@ -293,18 +299,16 @@ static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
 	return ERR_PTR(-EINVAL);
 }
 
-int ubifs_setxattr(struct dentry *dentry, const char *name,
-		   const void *value, size_t size, int flags)
+static int setxattr(struct inode *host, const char *name, const void *value,
+		    size_t size, int flags)
 {
-	struct inode *inode, *host = dentry->d_inode;
+	struct inode *inode;
 	struct ubifs_info *c = host->i_sb->s_fs_info;
 	struct qstr nm = QSTR_INIT(name, strlen(name));
 	struct ubifs_dent_node *xent;
 	union ubifs_key key;
 	int err, type;
 
-	dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd", name,
-		host->i_ino, dentry, size);
 	ubifs_assert(mutex_is_locked(&host->i_mutex));
 
 	if (size > UBIFS_MAX_INO_DATA)
@@ -356,6 +360,15 @@ out_free:
 	return err;
 }
 
+int ubifs_setxattr(struct dentry *dentry, const char *name,
+		   const void *value, size_t size, int flags)
+{
+	dbg_gen("xattr '%s', host ino %lu ('%pd'), size %zd",
+		name, dentry->d_inode->i_ino, dentry, size);
+
+	return setxattr(dentry->d_inode, name, value, size, flags);
+}
+
 ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
 		       size_t size)
 {
@@ -568,3 +581,84 @@ out_free:
 	kfree(xent);
 	return err;
 }
+
+static size_t security_listxattr(struct dentry *d, char *list, size_t list_size,
+				 const char *name, size_t name_len, int flags)
+{
+	const int prefix_len = XATTR_SECURITY_PREFIX_LEN;
+	const size_t total_len = prefix_len + name_len + 1;
+
+	if (list && total_len <= list_size) {
+		memcpy(list, XATTR_SECURITY_PREFIX, prefix_len);
+		memcpy(list + prefix_len, name, name_len);
+		list[prefix_len + name_len] = '\0';
+	}
+
+	return total_len;
+}
+
+static int security_getxattr(struct dentry *d, const char *name, void *buffer,
+		      size_t size, int flags)
+{
+	return ubifs_getxattr(d, name, buffer, size);
+}
+
+static int security_setxattr(struct dentry *d, const char *name,
+			     const void *value, size_t size, int flags,
+			     int handler_flags)
+{
+	return ubifs_setxattr(d, name, value, size, flags);
+}
+
+static const struct xattr_handler ubifs_xattr_security_handler = {
+	.prefix = XATTR_SECURITY_PREFIX,
+	.list   = security_listxattr,
+	.get    = security_getxattr,
+	.set    = security_setxattr,
+};
+
+const struct xattr_handler *ubifs_xattr_handlers[] = {
+	&ubifs_xattr_security_handler,
+	NULL,
+};
+
+static int init_xattrs(struct inode *inode, const struct xattr *xattr_array,
+		      void *fs_info)
+{
+	const struct xattr *xattr;
+	char *name;
+	int err = 0;
+
+	for (xattr = xattr_array; xattr->name != NULL; xattr++) {
+		name = kmalloc(XATTR_SECURITY_PREFIX_LEN +
+			       strlen(xattr->name) + 1, GFP_NOFS);
+		if (!name) {
+			err = -ENOMEM;
+			break;
+		}
+		strcpy(name, XATTR_SECURITY_PREFIX);
+		strcpy(name + XATTR_SECURITY_PREFIX_LEN, xattr->name);
+		err = setxattr(inode, name, xattr->value, xattr->value_len, 0);
+		kfree(name);
+		if (err < 0)
+			break;
+	}
+
+	return err;
+}
+
+int ubifs_init_security(struct inode *dentry, struct inode *inode,
+			const struct qstr *qstr)
+{
+	int err;
+
+	mutex_lock(&inode->i_mutex);
+	err = security_inode_init_security(inode, dentry, qstr,
+					   &init_xattrs, 0);
+	mutex_unlock(&inode->i_mutex);
+
+	if (err)
+		ubifs_err("cannot initialize security for inode %lu, error %d",
+			  inode->i_ino, err);
+	return err;
+}