From patchwork Sat Jun 10 17:07:43 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Demi Marie Obenour X-Patchwork-Id: 691596 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 15037C7EE2F for ; Sat, 10 Jun 2023 17:08:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230368AbjFJRIH (ORCPT ); Sat, 10 Jun 2023 13:08:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:56136 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230336AbjFJRIC (ORCPT ); Sat, 10 Jun 2023 13:08:02 -0400 Received: from out2-smtp.messagingengine.com (out2-smtp.messagingengine.com [66.111.4.26]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A16D22D68; Sat, 10 Jun 2023 10:08:01 -0700 (PDT) Received: from compute2.internal (compute2.nyi.internal [10.202.2.46]) by mailout.nyi.internal (Postfix) with ESMTP id 19C3F5C00F9; Sat, 10 Jun 2023 13:08:01 -0400 (EDT) Received: from mailfrontend1 ([10.202.2.162]) by compute2.internal (MEProxy); Sat, 10 Jun 2023 13:08:01 -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=1686416881; x=1686503281; bh=TmbhH/0ly3 pB3JOqGw89diUDufWw9j78goS8q6skCyk=; b=QVjheJeyM7p0c069LT+BuB4f0m JHFXKBOKLHyZdGN1dI7Xg2CHRbYbBz016p0MWQb1wJ0m/CkbOIqSGHQirxw9cB5r dtEKQIvGtiavzaAPLb7q48jcqNep5y25/EXr7KdUd5hOHtnYROPu4wlzgCv6qedJ V/i8hYS4e94/6Xn07dyYOoiU8WRkWNce47fxGLB++trtFUE4vZbDFbZ8TrAXCXqD zY7dq5ZsPRGpyARXLEtEeorMF3Kfy8QlNq3KZz4Db6g7l3s0FkhbI6BOM4g2t3sU 80XR4vln+Xcdb16w6e6yg9r63q43HfFl20Mi9EHQevPpHy+yXEYb9XO2LXRg== 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=1686416881; x= 1686503281; bh=TmbhH/0ly3pB3JOqGw89diUDufWw9j78goS8q6skCyk=; b=H 5Do6YlaaYtGxcuyqDWouK2yBlL0NP5Q1P/beUidzDtLeqCk6SyG+M/R7ZvvQh+GV iBJ1PoRejG08Zr3Z4PG9EM3VFoBUkRr82a1KGgKpA6CnRhnf6sKJOIev99096QfK UbjK09Z9bdS4FmAn01FvBycOBgBhe8ilmBauglnwjcEpUpkmcM+mFk9vZORX0Hz2 /8nvl3DfVH3bTjoHQ55VOJNj5vwNx9XuwCf1el4oW4sG1FTMzUHpCYZfoDpiDk+Z b1UtwrYqj7lVkY78zIfJAC6V0P47Y9+DqGP68ZkKbJiGasS7uDFS55edLaOiwtn1 Kfdj0Hlg5T0+A+XJvKazQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrgedutddgudduudcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefhvfevufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffvghm ihcuofgrrhhivgcuqfgsvghnohhurhcuoeguvghmihesihhnvhhishhisghlvghthhhinh hgshhlrggsrdgtohhmqeenucggtffrrghtthgvrhhnpeejffejgffgueegudevvdejkefg hefghffhffejteekleeufeffteffhfdtudehteenucevlhhushhtvghrufhiiigvpedtne curfgrrhgrmhepmhgrihhlfhhrohhmpeguvghmihesihhnvhhishhisghlvghthhhinhhg shhlrggsrdgtohhm X-ME-Proxy: Feedback-ID: iac594737:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Sat, 10 Jun 2023 13:07:59 -0400 (EDT) From: Demi Marie Obenour To: Hans de Goede , Mauro Carvalho Chehab , Sakari Ailus , Greg Kroah-Hartman , 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-media@vger.kernel.org, linux-staging@lists.linux.dev, linux-kernel@vger.kernel.org, xen-devel@lists.xenproject.org Subject: [PATCH v2 3/3] Strict XenStore entry parsing Date: Sat, 10 Jun 2023 13:07:43 -0400 Message-Id: <20230610170743.2510-4-demi@invisiblethingslab.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230610170743.2510-1-demi@invisiblethingslab.com> References: <20230610170743.2510-1-demi@invisiblethingslab.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org This rejects bogus xenstore node values that include e.g. leading spaces or overflow the expected integer type. Signed-off-by: Demi Marie Obenour --- drivers/xen/xenbus/xenbus_xs.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) diff --git a/drivers/xen/xenbus/xenbus_xs.c b/drivers/xen/xenbus/xenbus_xs.c index 12e02eb01f5991b31db451cc57037205359b347f..7cb2a22a7698ac40c81add23476594d9f27de8d0 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); 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(p, fmt, result) <= 0) ret = -EINVAL; kfree(p); } else