From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 10AC3C001DE for ; Sun, 16 Jul 2023 20:55:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233045AbjGPUzy (ORCPT ); Sun, 16 Jul 2023 16:55:54 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42582 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233048AbjGPUzx (ORCPT ); Sun, 16 Jul 2023 16:55:53 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 2E6D6E41 for ; Sun, 16 Jul 2023 13:55:53 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id C067660EBC for ; Sun, 16 Jul 2023 20:55:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C9A11C433C8; Sun, 16 Jul 2023 20:55:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1689540952; bh=e/erS0Qtrc5BnQazcB/s7JaCf9/gvGHjAnjvLvqbeRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=mYMT6J9f+e+T4u4t1Cpb4hH71A6K1ZRNnDn7oAsdVg1WNwz6VUh5xZHxsRbgZwInv ZnDtZrMVUhwgtKdnakMCIwm3ouEEc4u0ATfCUr6YH1BkJc81oP42DswW/MF1OY+IbT bIxTUhH7mTI1lGLfmJdbdhUwKZiu4BjXp9um8A/A= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?Thomas=20Wei=C3=9Fschuh?= , Christian Brauner Subject: [PATCH 6.1 546/591] fs: avoid empty option when generating legacy mount string Date: Sun, 16 Jul 2023 21:51:25 +0200 Message-ID: <20230716194937.987984790@linuxfoundation.org> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230716194923.861634455@linuxfoundation.org> References: <20230716194923.861634455@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Thomas Weißschuh commit 62176420274db5b5127cd7a0083a9aeb461756ee upstream. As each option string fragment is always prepended with a comma it would happen that the whole string always starts with a comma. This could be interpreted by filesystem drivers as an empty option and may produce errors. For example the NTFS driver from ntfs.ko behaves like this and fails when mounted via the new API. Link: https://github.com/util-linux/util-linux/issues/2298 Signed-off-by: Thomas Weißschuh Fixes: 3e1aeb00e6d1 ("vfs: Implement a filesystem superblock creation/configuration context") Cc: stable@vger.kernel.org Message-Id: <20230607-fs-empty-option-v1-1-20c8dbf4671b@weissschuh.net> Signed-off-by: Christian Brauner Signed-off-by: Greg Kroah-Hartman --- fs/fs_context.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/fs/fs_context.c +++ b/fs/fs_context.c @@ -561,7 +561,8 @@ static int legacy_parse_param(struct fs_ return -ENOMEM; } - ctx->legacy_data[size++] = ','; + if (size) + ctx->legacy_data[size++] = ','; len = strlen(param->key); memcpy(ctx->legacy_data + size, param->key, len); size += len;