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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 A6FC8C10F27 for ; Wed, 11 Mar 2020 09:35:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7CB5F2071B for ; Wed, 11 Mar 2020 09:35:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728255AbgCKJfy (ORCPT ); Wed, 11 Mar 2020 05:35:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:37314 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726160AbgCKJfy (ORCPT ); Wed, 11 Mar 2020 05:35:54 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 46A1DACEF; Wed, 11 Mar 2020 09:35:53 +0000 (UTC) From: Takashi Iwai To: "Darrick J . Wong" Cc: linux-xfs@vger.kernel.org Subject: [PATCH] xfs: Use scnprintf() for avoiding potential buffer overflow Date: Wed, 11 Mar 2020 10:35:52 +0100 Message-Id: <20200311093552.25354-1-tiwai@suse.de> X-Mailer: git-send-email 2.16.4 Sender: linux-xfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai --- fs/xfs/xfs_stats.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/xfs/xfs_stats.c b/fs/xfs/xfs_stats.c index 113883c4f202..f70f1255220b 100644 --- a/fs/xfs/xfs_stats.c +++ b/fs/xfs/xfs_stats.c @@ -57,13 +57,13 @@ int xfs_stats_format(struct xfsstats __percpu *stats, char *buf) /* Loop over all stats groups */ for (i = j = 0; i < ARRAY_SIZE(xstats); i++) { - len += snprintf(buf + len, PATH_MAX - len, "%s", + len += scnprintf(buf + len, PATH_MAX - len, "%s", xstats[i].desc); /* inner loop does each group */ for (; j < xstats[i].endpoint; j++) - len += snprintf(buf + len, PATH_MAX - len, " %u", + len += scnprintf(buf + len, PATH_MAX - len, " %u", counter_val(stats, j)); - len += snprintf(buf + len, PATH_MAX - len, "\n"); + len += scnprintf(buf + len, PATH_MAX - len, "\n"); } /* extra precision counters */ for_each_possible_cpu(i) { @@ -72,9 +72,9 @@ int xfs_stats_format(struct xfsstats __percpu *stats, char *buf) xs_read_bytes += per_cpu_ptr(stats, i)->s.xs_read_bytes; } - len += snprintf(buf + len, PATH_MAX-len, "xpc %Lu %Lu %Lu\n", + len += scnprintf(buf + len, PATH_MAX-len, "xpc %Lu %Lu %Lu\n", xs_xstrat_bytes, xs_write_bytes, xs_read_bytes); - len += snprintf(buf + len, PATH_MAX-len, "debug %u\n", + len += scnprintf(buf + len, PATH_MAX-len, "debug %u\n", #if defined(DEBUG) 1); #else -- 2.16.4