From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 01 Feb 2024 09:49:39 +0100 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 1rVSlO-00FMzC-0w for lore@lore.pengutronix.de; Thu, 01 Feb 2024 09:49:39 +0100 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 1rVSlO-0001tG-UM for lore@pengutronix.de; Thu, 01 Feb 2024 09:49:39 +0100 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: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=fI2+SmCt/9R1JiNNCIE9/wnzQtOwaenojPUbIPYvyak=; b=LUJkStB6RILSdK1qVQmvgt0l2z m4UXirUF6z+I6g4etSUatHXcDMdtxrAb/BDUIwsOaQKJstK2PAcIT0KGYE2rvtancTZBUx+FYrCLY a8mQvgS0xeW71lLrX1zclqHVeFamZBDB0yVVajA+sVAtGvIFkmA1gMaxFOy3aD55Ab62WFit0F4t5 nZpt3mURHW6rC0AeJ5ZdCqoiQV7ei9yYNCbV/LXDFwead0liBl/f+HSaSmHTSd8uDjfw+c0u76Em4 PTOH5nUPIo5L91DC0FZHJUfBSggVYr3ObZWBkpmeycKax3Y2pAUZ5aUMZyIzI6+OaW2jDCoz8L68q 5xoGgqHQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVSkt-000000079K2-3019; Thu, 01 Feb 2024 08:49:07 +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 1rVSkq-000000079JN-0nGf for barebox@lists.infradead.org; Thu, 01 Feb 2024 08:49:05 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[IPV6:::1]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.92) (envelope-from ) id 1rVSko-0001pa-Ap; Thu, 01 Feb 2024 09:49:02 +0100 Message-ID: <64705b99-a903-4ca7-820b-6695336946eb@pengutronix.de> Date: Thu, 1 Feb 2024 09:49:01 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Sascha Hauer Cc: BAREBOX References: <20240131-fix-fdt-memory-safety-v1-0-3d3a2c797eec@pengutronix.de> <20240131-fix-fdt-memory-safety-v1-2-3d3a2c797eec@pengutronix.de> <20240201074746.GH406126@pengutronix.de> Content-Language: en-US, de-DE From: Stefan Kerkmann In-Reply-To: <20240201074746.GH406126@pengutronix.de> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240201_004904_262768_A677B51A X-CRM114-Status: GOOD ( 19.99 ) 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=-6.2 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, T_SCC_BODY_TEXT_LINE autolearn=unavailable autolearn_force=no version=3.4.2 Subject: Re: [PATCH 2/2] of: fdt: fix oob writes with large ftd properties 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) Hi Sascha, On 01.02.24 08:47, Sascha Hauer wrote: > > In the subject: s/ftd/fdt/ > Applied. > Sascha > > On Wed, Jan 31, 2024 at 05:57:00PM +0100, Stefan Kerkmann wrote: >> OOB writes can be triggered when fdt->dt_size * 2 is still smaller than >> the property for which memory should be allocated. This can happen under >> rare circumstances when editing a fdt with the of_property command and a >> property is larger than 128k in size. >> >> This happend when editing a FIT image (which is a ftd) with the >> of_property command and the Kernel image was around 8M in size. >> >> The simplified call chain is the following: >> >> of_property -> of_flatten_dtb -> create new fdt with 64k in size (this is >> fixed) -> __of_flatten_dtb -> attempt to copy kernel image (8M) -> >> fdt_ensure_space -> allocate only 128k for fdt->dt -> memcopy 8M into fdt->dt >> buffer -> crash >> >> The fix is to grow fdt->dt to hold at least the new property. The power >> of 2 increment is untouched to keep the same behaviour otherwise. >> >> Signed-off-by: Stefan Kerkmann >> --- >> drivers/of/fdt.c | 4 ++++ >> 1 file changed, 4 insertions(+) >> >> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >> index 4f79a6120f..1f24ed0bbc 100644 >> --- a/drivers/of/fdt.c >> +++ b/drivers/of/fdt.c >> @@ -399,6 +399,10 @@ static int fdt_ensure_space(struct fdt *fdt, int dtsize) >> previous = fdt->dt; >> new_size = fdt->dt_size * 2; >> >> + while (new_size <= dtsize) { >> + new_size *= 2; >> + } >> + >> if ((fdt->dt = memalign_realloc(previous, fdt->dt_size, >> new_size)) == NULL) { >> free(previous); >> >> -- >> 2.39.2 >> >> > Cheers Stefan -- Pengutronix e.K. | Stefan Kerkmann | Steuerwalder Str. 21 | https://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-128 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-9 |