staging: erofs: fix memleak of inode's shared xattr array

From: Sheng Yong <shengyong1@huawei.com>

commit 3b1b5291 upstream.

If it fails to read a shared xattr page, the inode's shared xattr array
is not freed. The next time the inode's xattr is accessed, the previously
allocated array is leaked.
Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Fixes: b17500a0 ("staging: erofs: introduce xattr & acl support")
Cc: <stable@vger.kernel.org> # 4.19+
Reviewed-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/erofs/xattr.c

@@ -109,8 +109,11 @@ static int init_inode_xattrs(struct inode *inode)
 
 			it.page = erofs_get_meta_page(inode->i_sb,
 				++it.blkaddr, S_ISDIR(inode->i_mode));
-			if (IS_ERR(it.page))
+			if (IS_ERR(it.page)) {
+				kfree(vi->xattr_shared_xattrs);
+				vi->xattr_shared_xattrs = NULL;
 				return PTR_ERR(it.page);
+			}
 
 			it.kaddr = kmap_atomic(it.page);
 			atomic_map = true;