From nobody Mon Feb 9 21:19:07 2026 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 9390CC7EE23 for ; Thu, 1 Jun 2023 21:25:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231942AbjFAVZa (ORCPT ); Thu, 1 Jun 2023 17:25:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45682 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231499AbjFAVZU (ORCPT ); Thu, 1 Jun 2023 17:25:20 -0400 Received: from out5-smtp.messagingengine.com (out5-smtp.messagingengine.com [66.111.4.29]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8B7B6196; Thu, 1 Jun 2023 14:25:19 -0700 (PDT) Received: from compute4.internal (compute4.nyi.internal [10.202.2.44]) by mailout.nyi.internal (Postfix) with ESMTP id ED3F95C01D0; Thu, 1 Jun 2023 17:25:18 -0400 (EDT) Received: from mailfrontend2 ([10.202.2.163]) by compute4.internal (MEProxy); Thu, 01 Jun 2023 17:25:18 -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=1685654718; x=1685741118; bh=YZHd7YYjlD K6sv+mkKSJgYpLNyemRttpNw5QnchM4bE=; b=kS5wGTshap2i++C5h1+TcSncc2 FyNT5Ls4NghWOFzLklCX4jfQm1SrfiXo66GC2isWcdxhTthn0WyMAHJaWEIeAz+d BeX9M9RDPL9Y32OquGNX3RVXOvnLAhrGYDV+GrhQoe7w6g3Bo4YXRwDHWmbrjnY0 WNNLkrPKPXI5Q74v546DBQ2iNrddhKnRHV9xPTCveDoRefQPpBU4KmQqdG48oJ/6 G/W62z6gUVGPcamLkxaQUnvUXev+4NevkSbPwuH+6MD7sjFaBPbCTNg13yhHJ2EZ 7tdxmXFToLqpFMwqVK6xCQjEK7EwvWniq9DdGBOQLTmBrufHLPxrPaSi6FAQ== 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=1685654718; x= 1685741118; bh=YZHd7YYjlDK6sv+mkKSJgYpLNyemRttpNw5QnchM4bE=; b=B jqUds5OJLEiOrCvY8DDYia28d8+AGuiTY0nV6LPPKaTx+2zjEBJoQsS49+hlmZjI CCTkhS56YM2FuYbq7EQm58qze9jCa9ZEs/C13ZOvxaTI9Tl8pbvJ/knc4WZznSHQ MtZATudiq2KU6e7ye3tVGSloyyUNvbAW4ELQtPc0M/qLLs3q2CaW1WRBau8g0Zvz wwGCKiBv9yz6zE7qcgA3i62dbnnrgrNXScb/hXZjeWqxGtz9+SC7jIZY8C9L9uu1 Ydnv/N9NaPZM3jBZJ3mozb75d8Nt6Lv4EhXSHAlAXkNYFIosfaC3dGicb470Oi98 r+T0c9ScG7TQmBXyjXHMQ== X-ME-Sender: X-ME-Received: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgedvhedrfeeluddgudeiudcutefuodetggdotefrod ftvfcurfhrohhfihhlvgemucfhrghsthforghilhdpqfgfvfdpuffrtefokffrpgfnqfgh necuuegrihhlohhuthemuceftddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmd enucfjughrpefhvfevufffkffojghfggfgsedtkeertdertddtnecuhfhrohhmpeffvghm ihcuofgrrhhivgcuqfgsvghnohhurhcuoeguvghmihesihhnvhhishhisghlvghthhhinh hgshhlrggsrdgtohhmqeenucggtffrrghtthgvrhhnpeejffejgffgueegudevvdejkefg hefghffhffejteekleeufeffteffhfdtudehteenucevlhhushhtvghrufhiiigvpedtne curfgrrhgrmhepmhgrihhlfhhrohhmpeguvghmihesihhnvhhishhisghlvghthhhinhhg shhlrggsrdgtohhm X-ME-Proxy: Feedback-ID: iac594737:Fastmail Received: by mail.messagingengine.com (Postfix) with ESMTPA; Thu, 1 Jun 2023 17:25:18 -0400 (EDT) From: Demi Marie Obenour To: Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com Cc: Demi Marie Obenour , linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: [PATCH 3/6] device-mapper: structs and parameter strings must not overlap Date: Thu, 1 Jun 2023 17:24:52 -0400 Message-Id: <20230601212456.1533-4-demi@invisiblethingslab.com> X-Mailer: git-send-email 2.40.1 In-Reply-To: <20230601212456.1533-1-demi@invisiblethingslab.com> References: <20230601212456.1533-1-demi@invisiblethingslab.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" The NUL terminator for each target parameter string must precede the following 'struct dm_target_spec'. Otherwise, dm_split_args() might corrupt this struct. Furthermore, the first 'struct dm_target_spec' must come after the 'struct dm_ioctl', as if it overlaps too much dm_split_args() could corrupt the 'struct dm_ioctl'. Signed-off-by: Demi Marie Obenour Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Cc: stable@vger.kernel.org --- drivers/md/dm-ioctl.c | 28 +++++++++++++++++++++------- 1 file changed, 21 insertions(+), 7 deletions(-) diff --git a/drivers/md/dm-ioctl.c b/drivers/md/dm-ioctl.c index 64e8f16d344c47057de5e2d29e3d63202197dca0..da6ca26b51d0953df380582bb3a= 51c2ec22c27cb 100644 --- a/drivers/md/dm-ioctl.c +++ b/drivers/md/dm-ioctl.c @@ -1391,7 +1391,7 @@ static inline fmode_t get_mode(struct dm_ioctl *param) return mode; } =20 -static int next_target(struct dm_target_spec *last, uint32_t next, void *e= nd, +static int next_target(struct dm_target_spec *last, uint32_t next, const c= har *end, struct dm_target_spec **spec, char **target_params) { static_assert(_Alignof(struct dm_target_spec) <=3D 8, @@ -1404,7 +1404,7 @@ static int next_target(struct dm_target_spec *last, u= int32_t next, void *end, * sizeof(struct dm_target_spec) or more, as otherwise *last was * out of bounds already. */ - size_t remaining =3D (char *)end - (char *)last; + size_t remaining =3D end - (char *)last; =20 /* * There must be room for both the next target spec and the @@ -1423,10 +1423,7 @@ static int next_target(struct dm_target_spec *last, = uint32_t next, void *end, *spec =3D (struct dm_target_spec *) ((unsigned char *) last + next); *target_params =3D (char *) (*spec + 1); =20 - if (*spec < (last + 1)) - return -EINVAL; - - return invalid_str(*target_params, end); + return 0; } =20 static int populate_table(struct dm_table *table, @@ -1436,8 +1433,9 @@ static int populate_table(struct dm_table *table, unsigned int i =3D 0; struct dm_target_spec *spec =3D (struct dm_target_spec *) param; uint32_t next =3D param->data_start; - void *end =3D (void *) param + param_size; + const char *const end =3D (const char *) param + param_size; char *target_params; + size_t min_size =3D sizeof(struct dm_ioctl); =20 if (!param->target_count) { DMERR("%s: no targets specified", __func__); @@ -1445,6 +1443,13 @@ static int populate_table(struct dm_table *table, } =20 for (i =3D 0; i < param->target_count; i++) { + const char *nul_terminator; + + if (next < min_size) { + DMERR("%s: next target spec (offset %u) overlaps %s", + __func__, next, i ? "previous target" : "'struct dm_ioctl'"); + return -EINVAL; + } =20 r =3D next_target(spec, next, end, &spec, &target_params); if (r) { @@ -1452,6 +1457,15 @@ static int populate_table(struct dm_table *table, return r; } =20 + nul_terminator =3D memchr(target_params, 0, (size_t)(end - target_params= )); + if (nul_terminator =3D=3D NULL) { + DMERR("%s: target parameters not NUL-terminated", __func__); + return -EINVAL; + } + + /* Add 1 for NUL terminator */ + min_size =3D (size_t)(nul_terminator - (const char *)spec) + 1; + r =3D dm_table_add_target(table, spec->target_type, (sector_t) spec->sector_start, (sector_t) spec->length, --=20 Sincerely, Demi Marie Obenour (she/her/hers) Invisible Things Lab