From patchwork Mon Apr 19 14:14:05 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Colin King X-Patchwork-Id: 424340 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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, 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 B7651C43460 for ; Mon, 19 Apr 2021 14:14:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7F2FC61245 for ; Mon, 19 Apr 2021 14:14:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240693AbhDSOOl (ORCPT ); Mon, 19 Apr 2021 10:14:41 -0400 Received: from youngberry.canonical.com ([91.189.89.112]:33547 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S240246AbhDSOOi (ORCPT ); Mon, 19 Apr 2021 10:14:38 -0400 Received: from 1.general.cking.uk.vpn ([10.172.193.212] helo=localhost) by youngberry.canonical.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1lYUf7-00071L-Kc; Mon, 19 Apr 2021 14:14:05 +0000 From: Colin King To: Kalle Valo , "David S . Miller" , Jakub Kicinski , Arnd Bergmann , linux-wireless@vger.kernel.org, netdev@vger.kernel.org Cc: kernel-janitors@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH][next][V2] wlcore: Fix buffer overrun by snprintf due to incorrect buffer size Date: Mon, 19 Apr 2021 15:14:05 +0100 Message-Id: <20210419141405.180582-1-colin.king@canonical.com> X-Mailer: git-send-email 2.30.2 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Colin Ian King The size of the buffer than can be written to is currently incorrect, it is always the size of the entire buffer even though the snprintf is writing as position pos into the buffer. Fix this by setting the buffer size to be the number of bytes left in the buffer, namely sizeof(buf) - pos. Addresses-Coverity: ("Out-of-bounds access") Fixes: 7b0e2c4f6be3 ("wlcore: fix overlapping snprintf arguments in debugfs") Signed-off-by: Colin Ian King Reviewed-by: Arnd Bergmann --- V2: Fix patch subject --- drivers/net/wireless/ti/wlcore/debugfs.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/net/wireless/ti/wlcore/debugfs.h b/drivers/net/wireless/ti/wlcore/debugfs.h index 715edfa5f89f..a9e13e6d65c5 100644 --- a/drivers/net/wireless/ti/wlcore/debugfs.h +++ b/drivers/net/wireless/ti/wlcore/debugfs.h @@ -84,7 +84,7 @@ static ssize_t sub## _ ##name## _read(struct file *file, \ wl1271_debugfs_update_stats(wl); \ \ for (i = 0; i < len && pos < sizeof(buf); i++) \ - pos += snprintf(buf + pos, sizeof(buf), \ + pos += snprintf(buf + pos, sizeof(buf) - pos, \ "[%d] = %d\n", i, stats->sub.name[i]); \ \ return wl1271_format_buffer(userbuf, count, ppos, "%s", buf); \