From patchwork Mon Jul 12 06:09:26 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 476325 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=-19.4 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, 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 697B0C07E99 for ; Mon, 12 Jul 2021 06:22:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 563AD6112D for ; Mon, 12 Jul 2021 06:22:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234904AbhGLGZP (ORCPT ); Mon, 12 Jul 2021 02:25:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:38964 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235192AbhGLGYf (ORCPT ); Mon, 12 Jul 2021 02:24:35 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 70101611B0; Mon, 12 Jul 2021 06:21:24 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626070884; bh=xnWYHfObpQ+5Ip/l/lNmui/q8vAGzemHgguL1UMezNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YSNuKw7edjApF9zyhE/bh1LCwngAwxsh5IT4kawMKLnwEoZq8uXkxdzf5/40gTbhF AmTko0ydEhbNHbWYFA4ZxK1DGqnyBDQ0oWZK9Da2t9ldYVQf0hR1/tWhn56TvjVDu/ h6C7vlLIWOOKMOHf+Ta/0Tuqk8fKJw7ixmysxGIc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Joseph Qi , Mark Fasheh , Joel Becker , Junxiao Bi , Changwei Ge , Gang He , Jun Piao , Andrew Morton , Linus Torvalds , Sasha Levin Subject: [PATCH 5.4 182/348] ocfs2: fix snprintf() checking Date: Mon, 12 Jul 2021 08:09:26 +0200 Message-Id: <20210712060725.071516538@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210712060659.886176320@linuxfoundation.org> References: <20210712060659.886176320@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Dan Carpenter [ Upstream commit 54e948c60cc843b6e84dc44496edc91f51d2a28e ] The snprintf() function returns the number of bytes which would have been printed if the buffer was large enough. In other words it can return ">= remain" but this code assumes it returns "== remain". The run time impact of this bug is not very severe. The next iteration through the loop would trigger a WARN() when we pass a negative limit to snprintf(). We would then return success instead of -E2BIG. The kernel implementation of snprintf() will never return negatives so there is no need to check and I have deleted that dead code. Link: https://lkml.kernel.org/r/20210511135350.GV1955@kadam Fixes: a860f6eb4c6a ("ocfs2: sysfile interfaces for online file check") Fixes: 74ae4e104dfc ("ocfs2: Create stack glue sysfs files.") Signed-off-by: Dan Carpenter Reviewed-by: Joseph Qi Cc: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Cc: Changwei Ge Cc: Gang He Cc: Jun Piao Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin --- fs/ocfs2/filecheck.c | 6 +----- fs/ocfs2/stackglue.c | 8 ++------ 2 files changed, 3 insertions(+), 11 deletions(-) diff --git a/fs/ocfs2/filecheck.c b/fs/ocfs2/filecheck.c index 50f11bfdc8c2..82a3edc4aea4 100644 --- a/fs/ocfs2/filecheck.c +++ b/fs/ocfs2/filecheck.c @@ -328,11 +328,7 @@ static ssize_t ocfs2_filecheck_attr_show(struct kobject *kobj, ret = snprintf(buf + total, remain, "%lu\t\t%u\t%s\n", p->fe_ino, p->fe_done, ocfs2_filecheck_error(p->fe_status)); - if (ret < 0) { - total = ret; - break; - } - if (ret == remain) { + if (ret >= remain) { /* snprintf() didn't fit */ total = -E2BIG; break; diff --git a/fs/ocfs2/stackglue.c b/fs/ocfs2/stackglue.c index 8aa6a667860c..188038760136 100644 --- a/fs/ocfs2/stackglue.c +++ b/fs/ocfs2/stackglue.c @@ -502,11 +502,7 @@ static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj, list_for_each_entry(p, &ocfs2_stack_list, sp_list) { ret = snprintf(buf, remain, "%s\n", p->sp_name); - if (ret < 0) { - total = ret; - break; - } - if (ret == remain) { + if (ret >= remain) { /* snprintf() didn't fit */ total = -E2BIG; break; @@ -533,7 +529,7 @@ static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj, if (active_stack) { ret = snprintf(buf, PAGE_SIZE, "%s\n", active_stack->sp_name); - if (ret == PAGE_SIZE) + if (ret >= PAGE_SIZE) ret = -E2BIG; } spin_unlock(&ocfs2_stack_lock);