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=-16.7 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, UNWANTED_LANGUAGE_BODY,URIBL_BLOCKED,USER_AGENT_GIT 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 8B3E5C4338F for ; Mon, 26 Jul 2021 16:34:06 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BAA960234 for ; Mon, 26 Jul 2021 16:34:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239580AbhGZPxe (ORCPT ); Mon, 26 Jul 2021 11:53:34 -0400 Received: from mail.kernel.org ([198.145.29.99]:48256 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232402AbhGZPcM (ORCPT ); Mon, 26 Jul 2021 11:32:12 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id B202960F5A; Mon, 26 Jul 2021 16:12:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1627315941; bh=3hvMd/IAYmDN0sjkeWmBdjgWFqGKtAgVsF1jwa1xXhY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vGkikvAk8z9anGzPN5tsh5bJ9gGbdHYf/j1hEd0RWfeVk/xHoHtIsQjo8IMR/2L3j YeU2tM0t6BFSrlmuLRy1Vlx5Js2AudDpiSz3SS71YLEQuxxOMjFSUYkzfHm2rnXKbr uO6aDDhOKbjmnYtSGNtGSuUbtij+73oD4ZArPYF4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Tom Rix , David Howells , Marc Dionne , linux-afs@lists.infradead.org, Sasha Levin Subject: [PATCH 5.13 126/223] afs: check function return Date: Mon, 26 Jul 2021 17:38:38 +0200 Message-Id: <20210726153850.383876856@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210726153846.245305071@linuxfoundation.org> References: <20210726153846.245305071@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Tom Rix [ Upstream commit afe6949862f77bcc14fa16ad7938a04e84586d6a ] Static analysis reports this problem write.c:773:29: warning: Assigned value is garbage or undefined mapping->writeback_index = next; ^ ~~~~ The call to afs_writepages_region() can return without setting next. So check the function return before using next. Changes: ver #2: - Need to fix the range_cyclic case also[1]. Fixes: e87b03f5830e ("afs: Prepare for use of THPs") Signed-off-by: Tom Rix Signed-off-by: David Howells Reviewed-by: Marc Dionne cc: linux-afs@lists.infradead.org Link: https://lore.kernel.org/r/20210430155031.3287870-1-trix@redhat.com Link: https://lore.kernel.org/r/CAB9dFdvHsLsw7CMnB+4cgciWDSqVjuij4mH3TaXnHQB8sz5rHw@mail.gmail.com/ [1] Link: https://lore.kernel.org/r/162609464716.3133237.10354897554363093252.stgit@warthog.procyon.org.uk/ # v1 Link: https://lore.kernel.org/r/162610727640.3408253.8687445613469681311.stgit@warthog.procyon.org.uk/ # v2 Signed-off-by: Sasha Levin --- fs/afs/write.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-) diff --git a/fs/afs/write.c b/fs/afs/write.c index 3104b62c2082..1ed62e0ccfe5 100644 --- a/fs/afs/write.c +++ b/fs/afs/write.c @@ -771,13 +771,19 @@ int afs_writepages(struct address_space *mapping, if (wbc->range_cyclic) { start = mapping->writeback_index * PAGE_SIZE; ret = afs_writepages_region(mapping, wbc, start, LLONG_MAX, &next); - if (start > 0 && wbc->nr_to_write > 0 && ret == 0) - ret = afs_writepages_region(mapping, wbc, 0, start, - &next); - mapping->writeback_index = next / PAGE_SIZE; + if (ret == 0) { + mapping->writeback_index = next / PAGE_SIZE; + if (start > 0 && wbc->nr_to_write > 0) { + ret = afs_writepages_region(mapping, wbc, 0, + start, &next); + if (ret == 0) + mapping->writeback_index = + next / PAGE_SIZE; + } + } } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { ret = afs_writepages_region(mapping, wbc, 0, LLONG_MAX, &next); - if (wbc->nr_to_write > 0) + if (wbc->nr_to_write > 0 && ret == 0) mapping->writeback_index = next; } else { ret = afs_writepages_region(mapping, wbc, -- 2.30.2