From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 17 Jul 2024 09:29:45 +0200 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by lore.white.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1sTz6f-0006Tm-0m for lore@lore.pengutronix.de; Wed, 17 Jul 2024 09:29:45 +0200 Received: from bombadil.infradead.org ([2607:7c80:54:3::133]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1sTz6e-0007Uo-Kj for lore@pengutronix.de; Wed, 17 Jul 2024 09:29:45 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Cp2sjGwum871IESfDX8BEHlUSZ3hOU9QrPFa6Q85TYE=; b=hSb26WNFyvPvYf1aiTCfvZN5zX +/WqWoy/r89JIgiqEkO7iabftHwAIIqAFLP8N7EeZg3Ira4/iW3uQshfbA/O/d5aZZ1AxrBRLnORK GWoZofh4Fh4bbr+yktTXBb0f0pxE6m4nIfG6rL5d8z/SapPwZUGejDVjuJKpRnOA85sG47XtJg2bs snKicqPLJQIUZPAlX56BcxAg+p9AwKdr3P7qM8ARAzpjbFYYBRWJOizF+5GrVAMXaOfls8UUhz9U3 0WR4gmDbsDfjDP6HtrGcL+eh7vkTVib9pIn1ap0sLdhfpufWYP7h4YKMBXdAoVslbxxu6YuukZIoN gLVlleQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sTz6F-0000000CyoG-1EPM; Wed, 17 Jul 2024 07:29:19 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sTz6B-0000000CymE-3b0P for barebox@lists.infradead.org; Wed, 17 Jul 2024 07:29:17 +0000 Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1sTz6A-0007Iq-Kv; Wed, 17 Jul 2024 09:29:14 +0200 Received: from [2a0a:edc0:0:1101:1d::54] (helo=dude05.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1sTz6A-000A1p-7v; Wed, 17 Jul 2024 09:29:14 +0200 Received: from localhost ([::1] helo=dude05.red.stw.pengutronix.de) by dude05.red.stw.pengutronix.de with esmtp (Exim 4.96) (envelope-from ) id 1sTz6A-00BsTV-0U; Wed, 17 Jul 2024 09:29:14 +0200 From: Ahmad Fatoum To: barebox@lists.infradead.org Cc: Ahmad Fatoum Date: Wed, 17 Jul 2024 09:29:13 +0200 Message-Id: <20240717072913.2830995-3-a.fatoum@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240717072913.2830995-1-a.fatoum@pengutronix.de> References: <20240717072913.2830995-1-a.fatoum@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240717_002915_918172_9CBA520B X-CRM114-Status: GOOD ( 11.04 ) X-BeenThere: barebox@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "barebox" X-SA-Exim-Connect-IP: 2607:7c80:54:3::133 X-SA-Exim-Mail-From: barebox-bounces+lore=pengutronix.de@lists.infradead.org X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on metis.whiteo.stw.pengutronix.de X-Spam-Level: X-Spam-Status: No, score=-5.2 required=4.0 tests=AWL,BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_NONE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: [PATCH master 3/3] of: fdt: harden against corrupted reserve map entries X-SA-Exim-Version: 4.2.1 (built Wed, 08 May 2019 21:11:16 +0000) X-SA-Exim-Scanned: Yes (on metis.whiteo.stw.pengutronix.de) It's only safe to dereference r when dt_ptr_ok(fdt, r) determines that the r object is within the bounds of fdt. Commit 8a6b7db572c7 ("of: fdt: fix possibles overflows during parsing of invalid DTs") had a first attempt at enforcing this, but failed to do this for the very last element, so shift around the code, so we only every dereference r when it's safe to do so. Signed-off-by: Ahmad Fatoum --- drivers/of/fdt.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c index 8dca41990c87..f56f5802bb73 100644 --- a/drivers/of/fdt.c +++ b/drivers/of/fdt.c @@ -69,14 +69,14 @@ static int of_reservemap_num_entries(const struct fdt_header *fdt) r = (void *)fdt + be32_to_cpu(fdt->off_mem_rsvmap); - while (dt_ptr_ok(fdt, r) && r->size) { + while (dt_ptr_ok(fdt, r) && n < OF_MAX_RESERVE_MAP) { + if (!r->size) + return n; n++; r++; - if (n == OF_MAX_RESERVE_MAP) - return -EINVAL; } - return r->size == 0 ? n : -ESPIPE; + return n == OF_MAX_RESERVE_MAP ? -EINVAL : -ESPIPE; } /** -- 2.39.2