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 54424C76186 for ; Mon, 29 Jul 2019 19:30:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 285D921773 for ; Mon, 29 Jul 2019 19:30:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428640; bh=JLeOArumhw3pHEpAq0cX2sLAqcrHiDyam2CGdvxGhxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VkDo3q819AtGy03vyIB8jC+zxHc8pIsPBkH9tpbTBOvUgxNyIZ9gm67PLbtLVzdSz qcW6VobL0Pp/mDupaR7LXRn1ugKRbHjuxsnDC+B6DL8yq1geEiAdE+7QWG+6PzWHj9 OhX2GY7ui4yU+boK9akvKq6tbMbR2KAUk1pAqqbU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728748AbfG2Taj (ORCPT ); Mon, 29 Jul 2019 15:30:39 -0400 Received: from mail.kernel.org ([198.145.29.99]:43310 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728321AbfG2Taf (ORCPT ); Mon, 29 Jul 2019 15:30:35 -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 016762070B; Mon, 29 Jul 2019 19:30:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428634; bh=JLeOArumhw3pHEpAq0cX2sLAqcrHiDyam2CGdvxGhxQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oXs+bAXKhTMHmSkjpEEIEXmwJbM80Tu+t3IXKzSgi4qkozRi/SJ30RKIxFbcb2MF3 0/wtv/e4QfsmLqm3egV6KSiOI+DNJRrmOYW7otssLJqbe7qGDNmde2NwoWXqj95QVB 9HWL1zmjp9qrjql0i35guKxrXgsR3kEIQnmmxBlk= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christophe Leroy , Herbert Xu Subject: [PATCH 4.14 137/293] lib/scatterlist: Fix mapping iterator when sg->offset is greater than PAGE_SIZE Date: Mon, 29 Jul 2019 21:20:28 +0200 Message-Id: <20190729190835.044826789@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190820.321094988@linuxfoundation.org> References: <20190729190820.321094988@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 @@ -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); }