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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,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 EAAEFC433FF for ; Fri, 2 Aug 2019 09:51:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C337620880 for ; Fri, 2 Aug 2019 09:51:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739495; bh=JLeOArumhw3pHEpAq0cX2sLAqcrHiDyam2CGdvxGhxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=E3PoBah0d1hszFmLQNfglt5I1vc7xUvRJW23aYmuU3hhPEm5asb7SBw47qiZq6rIZ m8okHYmBgu5lTz2htJCiptC+YOsv+8ko1mj/ih8yvXfGX35h65ejdhqumAdy0JFYhy KWQdGM5m/uB0Bjxjhg+lhZ44KoRKswUILsMQUDVc= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2405869AbfHBJve (ORCPT ); Fri, 2 Aug 2019 05:51:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:48068 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2391547AbfHBJoj (ORCPT ); Fri, 2 Aug 2019 05:44:39 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.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 9080C206A2; Fri, 2 Aug 2019 09:44:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564739078; bh=JLeOArumhw3pHEpAq0cX2sLAqcrHiDyam2CGdvxGhxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=aC4KywNzdMrEJ4bVo/ofCfFWIvI4cNKZTFtab3+H4yGSSTYbiuyt6bc/HBXdfQePi 2v67rjOkaEso70X9B/B1p0VV1at1kKKOU76cUQf5djfVe/RnCk2wLlILF/3RgXi9Zq LxM20/RcChLoBKMfBVrZBjyZxk0/gzdXpGvQYJrU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Herbert Xu Subject: [PATCH 4.9 089/223] lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE Date: Fri, 2 Aug 2019 11:35:14 +0200 Message-Id: <20190802092244.851105063@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190802092238.692035242@linuxfoundation.org> References: <20190802092238.692035242@linuxfoundation.org> User-Agent: quilt/0.66 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 From: Christophe Leroy commit aeb87246537a83c2aff482f3f34a2e0991e02cbc upstream. All mapping iterator logic is based on the assumption that sg->offset is always lower than PAGE_SIZE. But there are situations where sg->offset is such that the SG item is on the second page. In that case sg_copy_to_buffer() fails properly copying the data into the buffer. One of the reason is that the data will be outside the kmapped area used to access that data. This patch fixes the issue by adjusting the mapping iterator offset and pgoffset fields such that offset is always lower than PAGE_SIZE. Signed-off-by: Christophe Leroy Fixes: 4225fc8555a9 ("lib/scatterlist: use page iterator in the mapping iterator") Cc: stable@vger.kernel.org Signed-off-by: Herbert Xu Signed-off-by: Greg Kroah-Hartman --- lib/scatterlist.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -496,17 +496,18 @@ static bool sg_miter_get_next_page(struc { if (!miter->__remaining) { struct scatterlist *sg; - unsigned long pgoffset; if (!__sg_page_iter_next(&miter->piter)) return false; sg = miter->piter.sg; - pgoffset = miter->piter.sg_pgoffset; - miter->__offset = pgoffset ? 0 : sg->offset; + miter->__offset = miter->piter.sg_pgoffset ? 0 : sg->offset; + miter->piter.sg_pgoffset += miter->__offset >> PAGE_SHIFT; + miter->__offset &= PAGE_SIZE - 1; miter->__remaining = sg->offset + sg->length - - (pgoffset << PAGE_SHIFT) - miter->__offset; + (miter->piter.sg_pgoffset << PAGE_SHIFT) - + miter->__offset; miter->__remaining = min_t(unsigned long, miter->__remaining, PAGE_SIZE - miter->__offset); }