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 872C8C7EE25 for ; Sat, 10 Jun 2023 02:59:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230236AbjFJC7p (ORCPT ); Fri, 9 Jun 2023 22:59:45 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53902 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233051AbjFJC7m (ORCPT ); Fri, 9 Jun 2023 22:59:42 -0400 Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id F259830D6; Fri, 9 Jun 2023 19:59:41 -0700 (PDT) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 6E1B05C01A3; Fri, 9 Jun 2023 22:59:41 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute2.internal (MEProxy); Fri, 09 Jun 2023 22:59:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= invisiblethingslab.com; h=cc:cc:content-transfer-encoding :content-type:date:date:from:from:in-reply-to:in-reply-to :message-id:mime-version:references:reply-to:sender:subject :subject:to:to; s=fm1; t=1686365981; x=1686452381; bh=9jx1BPUbfc VgExhjQbchVzVzEh8/1tbELFoG8PhPivY=; b=KzDj4AYYzePpimX6H5wkYZwkks NHGbQDu8jIRMdcSSSgF3b3PCmK7D2vOotKxA1DfVlTP2e08oG9cNjOaC0kyc2A/A Woeqakefd0epg23qLeX6igy3kxTwzSX6HLFhahqzHc+vqvIKm4sAeWi9aoNSXRR6 wCI5HfGLfst2I2vTH2hIA7ZxZ26JHuWYOCEEPQPqUdH0cH2Rrtx60UFtXGXkXHdo oHHe5NzrKGAz0eOgRzDoxWrkDYMlWiOGDPj/JZbnnXGfaI+2MtyHouaGMcEBMaZV jdSrar5Q0z3nIwuLL3W3Xx2b6XH6XjVb12K0C8yZS0BhFD3XVFZWGvJ79QUg== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:date:date:feedback-id:feedback-id:from:from :in-reply-to:in-reply-to:message-id:mime-version:references :reply-to:sender:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm1; t=1686365981; x= 1686452381; bh=9jx1BPUbfcVgExhjQbchVzVzEh8/1tbELFoG8PhPivY=; b=Z vSpafDBLwDL8H2CTo8lfIfv0lBZ6g4SdgNNNWgwt9+71cFO74vFRkfX5OQ0eun+2 V9U7u1FWaanTOidIYHn+FaDRXl+fpQTdsWaByWb8JDChI4RHKW0Er7WreEW70XSH F7ovWDNSgioIcLiDVSE1DlAfe687KvI/kOFQUYI5cJrhQ5FVuqQj+0k+MXIqK2ZF 5YIcEJ5iqfquW6njaZXeLisvjATivHd3InKEgpO6av2xMmSPYJ9xVUx7M/y8yarE v1ZhBTL4ViFGSyXf3rk89tTMCKeP0BpWjJ6L5NGJkGZn6HsrPPsYg/Mr1c8kHU06 REVYBioVQJyWfzr6tnZjw== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgedtledgieegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdfqfgfvpdfurfetoffkrfgpnffqhgen uceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnhhtshculddquddttddmne cujfgurhephffvvefufffkofgjfhgggfestdekredtredttdenucfhrhhomhepffgvmhhi ucforghrihgvucfqsggvnhhouhhruceouggvmhhisehinhhvihhsihgslhgvthhhihhngh hslhgrsgdrtghomheqnecuggftrfgrthhtvghrnhepjeffjefggfeugeduvedvjeekgfeh gffhhfffjeetkeelueefffetfffhtdduheetnecuvehluhhsthgvrhfuihiivgeptdenuc frrghrrghmpehmrghilhhfrhhomhepuggvmhhisehinhhvihhsihgslhgvthhhihhnghhs lhgrsgdrtghomh X-ME-Proxy: Feedback-ID: iac594737:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Fri, 9 Jun 2023 22:59:40 -0400 (EDT) From: Demi Marie Obenour To: Dwaipayan Ray , Lukas Bulwahn , Joe Perches , Jonathan Corbet , Federico Vaga , Juergen Gross , Stefano Stabellini , Oleksandr Tyshchenko , Lee Jones , Andy Lutomirski , Thomas Gleixner , Vincenzo Frascino , Petr Mladek , Steven Rostedt , Sergey Senozhatsky , Andy Shevchenko , Rasmus Villemoes Cc: Demi Marie Obenour , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Subject: [PATCH 4/4] Strict XenStore entry parsing Date: Fri, 9 Jun 2023 22:57:59 -0400 Message-Id: <20230610025759.1813-4-demi@invisiblethingslab.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230610025759.1813-1-demi@invisiblethingslab.com> References: <20230610025759.1813-1-demi@invisiblethingslab.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-doc@vger.kernel.org This uses the newly-introduced strict version of sscanf(). Signed-off-by: Demi Marie Obenour --- drivers/xen/xenbus/xenbus_xs.c | 19 +++++++++++++------ 1 file changed, 13 insertions(+), 6 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 12e02eb01f5991b31db451cc57037205359b347f..88e94269c9221d16d1a97e59399058e870675729 100644 --- a/drivers/xen/xenbus/xenbus_xs.c +++ b/drivers/xen/xenbus/xenbus_xs.c @@ -569,16 +569,20 @@ int xenbus_scanf(struct xenbus_transaction t, const char *dir, const char *node, const char *fmt, ...) { va_list ap; - int ret; + int ret = 0; + unsigned int len; char *val; - val = xenbus_read(t, dir, node, NULL); + val = xenbus_read(t, dir, node, &len); if (IS_ERR(val)) return PTR_ERR(val); + if (strlen(val) != len) + goto bad; va_start(ap, fmt); - ret = vsscanf(val, fmt, ap); + ret = vsscanf_strict(val, fmt, ap); va_end(ap); +bad: kfree(val); /* Distinctive errno. */ if (ret == 0) @@ -636,15 +640,18 @@ int xenbus_gather(struct xenbus_transaction t, const char *dir, ...) while (ret == 0 && (name = va_arg(ap, char *)) != NULL) { const char *fmt = va_arg(ap, char *); void *result = va_arg(ap, void *); + unsigned len; char *p; - p = xenbus_read(t, dir, name, NULL); + p = xenbus_read(t, dir, name, &len); if (IS_ERR(p)) { ret = PTR_ERR(p); break; } - if (fmt) { - if (sscanf(p, fmt, result) == 0) + if (strlen(p) != len) + ret = -EINVAL; + else if (fmt) { + if (sscanf_strict(p, fmt, result) <= 0) ret = -EINVAL; kfree(p); } else -- Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab