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 X-Spam-Level: X-Spam-Status: No, score=-10.0 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 88392C43387 for ; Fri, 28 Dec 2018 12:21:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4D57720675 for ; Fri, 28 Dec 2018 12:21:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545999713; bh=bJdqvnntYfA/zPUOoTZ0Rrgy8zbN+XxR/YewiHqlVtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mxm09DxvjJ3/M6UZygpY9J6yVnjKYy6c5k+LN0Q+gxHeMZBZjlGhn/or/b5kOG1uW IcSEhwSRy5WPpZO97opXKMI70YtAenLpO10mmAqZOXZyfNS2c3oJ9Go/niIUvQ+vOE rA5GSwUgL4DbVVUNJIl3d4WjslCTKy2bE+WKAZFY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732529AbeL1MPt (ORCPT ); Fri, 28 Dec 2018 07:15:49 -0500 Received: from mail.kernel.org ([198.145.29.99]:34792 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732506AbeL1MPp (ORCPT ); Fri, 28 Dec 2018 07:15:45 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 47ADF2087F; Fri, 28 Dec 2018 12:15:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1545999344; bh=bJdqvnntYfA/zPUOoTZ0Rrgy8zbN+XxR/YewiHqlVtw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TvF+5bTopDSl/8TCm9c69X4O4mMnziMTMKJTBvxHzx3dE+475hllNLZXWtg1KiXFD gD+7jUNxwQ6GarztRRPere+XfPS0KoiE6gnr7MCxQ7G5YIuzuP3HCBNOOKPi7RzVFy +DdgLeT1LBFwtaEz1XvVs9qOylv3XLlLjxuiZ/yo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mikulas Patocka , Jens Axboe , Sasha Levin Subject: [PATCH 4.14 02/36] block: fix infinite loop if the device loses discard capability Date: Fri, 28 Dec 2018 12:52:18 +0100 Message-Id: <20181228113126.684445611@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20181228113126.526729877@linuxfoundation.org> References: <20181228113126.526729877@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.14-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit b88aef36b87c9787a4db724923ec4f57dfd513f3 ] If __blkdev_issue_discard is in progress and a device mapper device is reloaded with a table that doesn't support discard, q->limits.max_discard_sectors is set to zero. This results in infinite loop in __blkdev_issue_discard. This patch checks if max_discard_sectors is zero and aborts with -EOPNOTSUPP. Signed-off-by: Mikulas Patocka Tested-by: Zdenek Kabelac Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin --- block/blk-lib.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/block/blk-lib.c b/block/blk-lib.c index 53a45663e688..0bdc77888dc5 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -65,6 +65,8 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, */ req_sects = min_t(sector_t, nr_sects, q->limits.max_discard_sectors); + if (!req_sects) + goto fail; if (req_sects > UINT_MAX >> 9) req_sects = UINT_MAX >> 9; @@ -102,6 +104,14 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, *biop = bio; return 0; + +fail: + if (bio) { + submit_bio_wait(bio); + bio_put(bio); + } + *biop = NULL; + return -EOPNOTSUPP; } EXPORT_SYMBOL(__blkdev_issue_discard); -- 2.19.1