From patchwork Tue Jan 8 11:42:09 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Filipe Manana X-Patchwork-Id: 10751901 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 0D84091E for ; Tue, 8 Jan 2019 11:42:15 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id F18A728C1A for ; Tue, 8 Jan 2019 11:42:14 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id E649528C24; Tue, 8 Jan 2019 11:42:14 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8FB5528C19 for ; Tue, 8 Jan 2019 11:42:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728681AbfAHLmN (ORCPT ); Tue, 8 Jan 2019 06:42:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:49168 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728679AbfAHLmM (ORCPT ); Tue, 8 Jan 2019 06:42:12 -0500 Received: from localhost.localdomain (bl8-197-74.dsl.telepac.pt [85.241.197.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 45F9E206B7 for ; Tue, 8 Jan 2019 11:42:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1546947731; bh=s24e4wzdEhnkVTXIMZe/DZ3MM9tHtxmIOACgnY4L5MQ=; h=From:To:Subject:Date:In-Reply-To:References:From; b=ycMulcLW/EEst7kMHCM5mSgDgyu23lVaqCiI6YRDu3jlvu9xB6ow++4YJbzxSISqH TeYtNe/QtFG9bOJg9H5HgFwwvqrAp111WzjDcS9wXEhFs4YBlItm8GETtAC/ICM+ya sADM8/bZwf8uaNT1ruOTT86CFFvmZ3yeNtMZsV/8= From: fdmanana@kernel.org To: linux-btrfs@vger.kernel.org Subject: [PATCH v2] Btrfs: do not overwrite error return value in the device replace ioctl Date: Tue, 8 Jan 2019 11:42:09 +0000 Message-Id: <20190108114209.2137-1-fdmanana@kernel.org> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20181214194532.21841-1-fdmanana@kernel.org> References: <20181214194532.21841-1-fdmanana@kernel.org> Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP From: Filipe Manana If the call to btrfs_dev_replace_by_ioctl() failed we would overwrite the error returned to user space with -EFAULT if the call to copy_to_user() failed as well. Fix that by calling copy_to_user() only if no error happened before or a device replace operation was canceled. Signed-off-by: Filipe Manana Reviewed-by: David Sterba --- V2: Considered the case where the device replace operation is canceled. fs/btrfs/ioctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index 8dbb4ed07da1..0db60bfee99a 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -4462,7 +4462,7 @@ static long btrfs_ioctl_dev_replace(struct btrfs_fs_info *fs_info, break; } - if (copy_to_user(arg, p, sizeof(*p))) + if ((ret == 0 || ret == -ECANCELED) && copy_to_user(arg, p, sizeof(*p))) ret = -EFAULT; out: kfree(p);