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,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 ACD2AC7618F for ; Wed, 24 Jul 2019 19:56:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 760B622BEB for ; Wed, 24 Jul 2019 19:56:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998211; bh=dW9JTn8nEaaE0+3GmnwWqHXGXU+tjSb0jTUMRVNkOfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=qjNqO1Ga5D9GugMF8FCG9zkcZtfQTFDyBkP0mxSFItoiVvPiLSWpR6slrNRTD2zgm cXNif/6PugymkO2QuqNLf3SKQj2zNpkMXnMZ8EhSwvHc1o3pN12hKAnsATAdRacP4a fneJedoSgW+DfTON/+Cq4ZB1F/AFQwNcMzFMZ5R8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2404017AbfGXT4u (ORCPT ); Wed, 24 Jul 2019 15:56:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:41550 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2404404AbfGXT4s (ORCPT ); Wed, 24 Jul 2019 15:56:48 -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 F0A3021873; Wed, 24 Jul 2019 19:56:46 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563998207; bh=dW9JTn8nEaaE0+3GmnwWqHXGXU+tjSb0jTUMRVNkOfo=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=SQJwLEtYGm2dRoY6veUq8qgmRb0E4sCzfXEYWwyTucMLOeJZQMIducQa8qUscuCuV dMOl74pPwU9ufDaEedhMpOXm+0UZ46LwoEHG6Q30lWOat8Sy1g7aB1frAsTVJ/BOSy NCEK0shqXmOhcXaleOzluHiObrJeL714mrbMUndU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Herbert Xu Subject: [PATCH 5.1 283/371] lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE Date: Wed, 24 Jul 2019 21:20:35 +0200 Message-Id: <20190724191745.573167231@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190724191724.382593077@linuxfoundation.org> References: <20190724191724.382593077@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@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 @@ -678,17 +678,18 @@ 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); }