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=-16.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=unavailable 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 9DAD1C4320E for ; Fri, 27 Aug 2021 16:49:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7C00C60FF2 for ; Fri, 27 Aug 2021 16:49:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233280AbhH0Qug (ORCPT ); Fri, 27 Aug 2021 12:50:36 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:42263 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230021AbhH0Que (ORCPT ); Fri, 27 Aug 2021 12:50:34 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1630082984; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JHGCqTXkarbKxG5+YktM4Z+cMzywabkx4H8cpyRRiOI=; b=DpuFPyEWqXaRLCYcTHwL0ZvxN84Igr62UNebX2mZ2Skp+8aS81Lw0yOP6/Dos6WcziUc/8 7tzlOB49Crhaq7UBwpp05aPJfcDre6/vNKFyO5hzbwdXWR2h/MvPf6p/4CiurSmG6CUxqC 466RCB8E+VolnHTQwOmwqGQweUnTGcU= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-408-K6bUU1ssO_-VLMFwtR0PBw-1; Fri, 27 Aug 2021 12:49:43 -0400 X-MC-Unique: K6bUU1ssO_-VLMFwtR0PBw-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 1F034801B3C; Fri, 27 Aug 2021 16:49:42 +0000 (UTC) Received: from max.com (unknown [10.40.194.206]) by smtp.corp.redhat.com (Postfix) with ESMTP id F04BA60C04; Fri, 27 Aug 2021 16:49:38 +0000 (UTC) From: Andreas Gruenbacher To: Linus Torvalds , Alexander Viro , Christoph Hellwig , "Darrick J. Wong" Cc: Jan Kara , Matthew Wilcox , cluster-devel@redhat.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, ocfs2-devel@oss.oracle.com, Andreas Gruenbacher Subject: [PATCH v7 01/19] iov_iter: Fix iov_iter_get_pages{,_alloc} page fault return value Date: Fri, 27 Aug 2021 18:49:08 +0200 Message-Id: <20210827164926.1726765-2-agruenba@redhat.com> In-Reply-To: <20210827164926.1726765-1-agruenba@redhat.com> References: <20210827164926.1726765-1-agruenba@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Both iov_iter_get_pages and iov_iter_get_pages_alloc return the number of bytes of the iovec they could get the pages for. When they cannot get any pages, they're supposed to return 0, but when the start of the iovec isn't page aligned, the calculation goes wrong and they return a negative value. Fix both functions. In addition, change iov_iter_get_pages_alloc to return NULL in that case to prevent resource leaks. Signed-off-by: Andreas Gruenbacher --- lib/iov_iter.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/iov_iter.c b/lib/iov_iter.c index e23123ae3a13..25dfc48536d7 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -1484,7 +1484,7 @@ ssize_t iov_iter_get_pages(struct iov_iter *i, res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, pages); - if (unlikely(res < 0)) + if (unlikely(res <= 0)) return res; return (res == n ? len : res * PAGE_SIZE) - *start; } @@ -1608,8 +1608,9 @@ ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, return -ENOMEM; res = get_user_pages_fast(addr, n, iov_iter_rw(i) != WRITE ? FOLL_WRITE : 0, p); - if (unlikely(res < 0)) { + if (unlikely(res <= 0)) { kvfree(p); + *pages = NULL; return res; } *pages = p; -- 2.26.3