From patchwork Thu Mar 15 15:08:11 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bart Van Assche X-Patchwork-Id: 10284717 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 008B360386 for ; Thu, 15 Mar 2018 15:08:36 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id EAAF428A57 for ; Thu, 15 Mar 2018 15:08:35 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DFBE828B1E; Thu, 15 Mar 2018 15:08:35 +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=-6.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,T_DKIM_INVALID 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 8A28628A57 for ; Thu, 15 Mar 2018 15:08:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752795AbeCOPIe (ORCPT ); Thu, 15 Mar 2018 11:08:34 -0400 Received: from esa2.hgst.iphmx.com ([68.232.143.124]:23307 "EHLO esa2.hgst.iphmx.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752820AbeCOPIb (ORCPT ); Thu, 15 Mar 2018 11:08:31 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=wdc.com; i=@wdc.com; q=dns/txt; s=dkim.wdc.com; t=1521127620; x=1552663620; h=from:to:cc:subject:date:message-id:in-reply-to: references; bh=Z2omrg75P6oADuaCIaKmt6pofFynj5GReD6iQGZUdEk=; b=d9hrhVbKHMEWl2Nlli0mTbtAUr8vxyNQaMoEZygyjp7BYDskZWbswtec Yj1UtNek7cxt+gKh0X8RB6IrS5VPOLQEvKDIWnt2EFcs1cThRkl9pkhfQ OGxKEn4Ukgq1GZsMMSXBlsH82SdY94nuI3+9gf8lYEyBHVDC52iMTo2yF PdjBxAym7Z7xa+lDw6ktW37sde+t4xw4LAOjPheEYPuYiT/vDV/k1A50z 6xhrLYWopJ9BscVX7S2NALyTbF+RcuYfNG84COEPEEQxVFbfqdvZGwZR+ STCw2UdN3MLgQRu0foRLY+PMn747bl4MzEEoeK6fk8wNQgsvbirJla1/l A==; X-IronPort-AV: E=Sophos;i="5.47,471,1515427200"; d="scan'208";a="170233276" Received: from h199-255-45-15.hgst.com (HELO uls-op-cesaep02.wdc.com) ([199.255.45.15]) by ob1.hgst.iphmx.com with ESMTP; 15 Mar 2018 23:26:38 +0800 Received: from uls-op-cesaip02.wdc.com ([10.248.3.37]) by uls-op-cesaep02.wdc.com with ESMTP; 15 Mar 2018 08:01:15 -0700 Received: from thinkpad-bart.sdcorp.global.sandisk.com (HELO thinkpad-bart.int.fusionio.com) ([10.11.171.236]) by uls-op-cesaip02.wdc.com with ESMTP; 15 Mar 2018 08:08:17 -0700 From: Bart Van Assche To: Michael Lyle , Kent Overstreet , Coly Li Cc: linux-block@vger.kernel.org, Christoph Hellwig , Bart Van Assche Subject: [PATCH 13/16] bcache: Make bch_dump_read() fail if copying to user space fails Date: Thu, 15 Mar 2018 08:08:11 -0700 Message-Id: <20180315150814.9412-14-bart.vanassche@wdc.com> X-Mailer: git-send-email 2.16.2 In-Reply-To: <20180315150814.9412-1-bart.vanassche@wdc.com> References: <20180315150814.9412-1-bart.vanassche@wdc.com> Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP copy_to_user() returns the number of remaining bytes. Avoid that a larger value is returned than the number of bytes that have been copied by returning -EFAULT if not all bytes have been copied. Signed-off-by: Bart Van Assche --- drivers/md/bcache/debug.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/drivers/md/bcache/debug.c b/drivers/md/bcache/debug.c index af89408befe8..376899cfcbf1 100644 --- a/drivers/md/bcache/debug.c +++ b/drivers/md/bcache/debug.c @@ -175,9 +175,8 @@ static ssize_t bch_dump_read(struct file *file, char __user *buf, struct keybuf_key *w; unsigned bytes = min(i->bytes, size); - int err = copy_to_user(buf, i->buf, bytes); - if (err) - return err; + if (copy_to_user(buf, i->buf, bytes)) + return -EFAULT; ret += bytes; buf += bytes;