1 files changed, 127 insertions, 0 deletions
diff --git a/fs/reiserfs/xattr_security.c b/fs/reiserfs/xattr_security.c
new file mode 100644
index 0000000000..078dd8cc31
--- /dev/null
+++ b/fs/reiserfs/xattr_security.c
@@ -0,0 +1,127 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "reiserfs.h"
+#include <linux/errno.h>
+#include <linux/fs.h>
+#include <linux/pagemap.h>
+#include <linux/xattr.h>
+#include <linux/slab.h>
+#include "xattr.h"
+#include <linux/security.h>
+#include <linux/uaccess.h>
+
+static int
+security_get(const struct xattr_handler *handler, struct dentry *unused,
+	     struct inode *inode, const char *name, void *buffer, size_t size)
+{
+	if (IS_PRIVATE(inode))
+		return -EPERM;
+
+	return reiserfs_xattr_get(inode, xattr_full_name(handler, name),
+				  buffer, size);
+}
+
+static int
+security_set(const struct xattr_handler *handler,
+	     struct mnt_idmap *idmap, struct dentry *unused,
+	     struct inode *inode, const char *name, const void *buffer,
+	     size_t size, int flags)
+{
+	if (IS_PRIVATE(inode))
+		return -EPERM;
+
+	return reiserfs_xattr_set(inode,
+				  xattr_full_name(handler, name),
+				  buffer, size, flags);
+}
+
+static bool security_list(struct dentry *dentry)
+{
+	return !IS_PRIVATE(d_inode(dentry));
+}
+
+static int
+reiserfs_initxattrs(struct inode *inode, const struct xattr *xattr_array,
+		    void *fs_info)
+{
+	struct reiserfs_security_handle *sec = fs_info;
+
+	sec->value = kmemdup(xattr_array->value, xattr_array->value_len,
+			     GFP_KERNEL);
+	if (!sec->value)
+		return -ENOMEM;
+
+	sec->name = xattr_array->name;
+	sec->length = xattr_array->value_len;
+	return 0;
+}
+
+/* Initializes the security context for a new inode and returns the number
+ * of blocks needed for the transaction. If successful, reiserfs_security
+ * must be released using reiserfs_security_free when the caller is done. */
+int reiserfs_security_init(struct inode *dir, struct inode *inode,
+			   const struct qstr *qstr,
+			   struct reiserfs_security_handle *sec)
+{
+	int blocks = 0;
+	int error;
+
+	sec->name = NULL;
+	sec->value = NULL;
+	sec->length = 0;
+
+	/* Don't add selinux attributes on xattrs - they'll never get used */
+	if (IS_PRIVATE(dir))
+		return 0;
+
+	error = security_inode_init_security(inode, dir, qstr,
+					     &reiserfs_initxattrs, sec);
+	if (error) {
+		sec->name = NULL;
+		sec->value = NULL;
+		sec->length = 0;
+		return error;
+	}
+
+	if (sec->length && reiserfs_xattrs_initialized(inode->i_sb)) {
+		blocks = reiserfs_xattr_jcreate_nblocks(inode) +
+			 reiserfs_xattr_nblocks(inode, sec->length);
+		/* We don't want to count the directories twice if we have
+		 * a default ACL. */
+		REISERFS_I(inode)->i_flags |= i_has_xattr_dir;
+	}
+	return blocks;
+}
+
+int reiserfs_security_write(struct reiserfs_transaction_handle *th,
+			    struct inode *inode,
+			    struct reiserfs_security_handle *sec)
+{
+	char xattr_name[XATTR_NAME_MAX + 1] = XATTR_SECURITY_PREFIX;
+	int error;
+
+	if (XATTR_SECURITY_PREFIX_LEN + strlen(sec->name) > XATTR_NAME_MAX)
+		return -EINVAL;
+
+	strlcat(xattr_name, sec->name, sizeof(xattr_name));
+
+	error = reiserfs_xattr_set_handle(th, inode, xattr_name, sec->value,
+					  sec->length, XATTR_CREATE);
+	if (error == -ENODATA || error == -EOPNOTSUPP)
+		error = 0;
+
+	return error;
+}
+
+void reiserfs_security_free(struct reiserfs_security_handle *sec)
+{
+	kfree(sec->value);
+	sec->name = NULL;
+	sec->value = NULL;
+}
+
+const struct xattr_handler reiserfs_xattr_security_handler = {
+	.prefix = XATTR_SECURITY_PREFIX,
+	.get = security_get,
+	.set = security_set,
+	.list = security_list,
+};