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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4DD8FA3740 for ; Mon, 24 Oct 2022 13:26:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230102AbiJXNZu (ORCPT ); Mon, 24 Oct 2022 09:25:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56518 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234058AbiJXNXB (ORCPT ); Mon, 24 Oct 2022 09:23:01 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8C6A12F397; Mon, 24 Oct 2022 05:29:59 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D997A612E9; Mon, 24 Oct 2022 12:27:56 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EC516C433D6; Mon, 24 Oct 2022 12:27:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1666614476; bh=AlKGxA5oHb1mhMs88++LuDXBhLryEnVpofotGpHubyE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=k5uMHShrY1q2NtApzvhZieoSnKLhkEktpFNG9HOCNpVmRTYp0JEIrwk+6au1sjCvM FcPfkEKiY7SA4l5UtX1jRcxclubOGDFJ8GB2JKsnwp0hpAcPur8+KcyBvawluaWahm Zw0nXrV6yWiRQK3+m+ZPdxvvV1np83CQwW5GXnPc= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Dan Carpenter , Robin Murphy , Laurent Pinchart , Joerg Roedel , Sasha Levin Subject: [PATCH 5.10 275/390] iommu/omap: Fix buffer overflow in debugfs Date: Mon, 24 Oct 2022 13:31:12 +0200 Message-Id: <20221024113034.648307904@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221024113022.510008560@linuxfoundation.org> References: <20221024113022.510008560@linuxfoundation.org> User-Agent: quilt/0.67 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: Dan Carpenter [ Upstream commit 184233a5202786b20220acd2d04ddf909ef18f29 ] There are two issues here: 1) The "len" variable needs to be checked before the very first write. Otherwise if omap2_iommu_dump_ctx() with "bytes" less than 32 it is a buffer overflow. 2) The snprintf() function returns the number of bytes that *would* have been copied if there were enough space. But we want to know the number of bytes which were *actually* copied so use scnprintf() instead. Fixes: bd4396f09a4a ("iommu/omap: Consolidate OMAP IOMMU modules") Signed-off-by: Dan Carpenter Reviewed-by: Robin Murphy Reviewed-by: Laurent Pinchart Link: https://lore.kernel.org/r/YuvYh1JbE3v+abd5@kili Signed-off-by: Joerg Roedel Signed-off-by: Sasha Levin --- drivers/iommu/omap-iommu-debug.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/iommu/omap-iommu-debug.c b/drivers/iommu/omap-iommu-debug.c index a99afb5d9011..259f65291d90 100644 --- a/drivers/iommu/omap-iommu-debug.c +++ b/drivers/iommu/omap-iommu-debug.c @@ -32,12 +32,12 @@ static inline bool is_omap_iommu_detached(struct omap_iommu *obj) ssize_t bytes; \ const char *str = "%20s: %08x\n"; \ const int maxcol = 32; \ - bytes = snprintf(p, maxcol, str, __stringify(name), \ + if (len < maxcol) \ + goto out; \ + bytes = scnprintf(p, maxcol, str, __stringify(name), \ iommu_read_reg(obj, MMU_##name)); \ p += bytes; \ len -= bytes; \ - if (len < maxcol) \ - goto out; \ } while (0) static ssize_t -- 2.35.1