From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Thu, 01 Feb 2024 08:48:34 +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 1rVRoH-00FHl0-1N for lore@lore.pengutronix.de; Thu, 01 Feb 2024 08:48:34 +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 1rVRoI-0007Iy-2Z for lore@pengutronix.de; Thu, 01 Feb 2024 08:48:34 +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:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=ki7zy2T62yjaVrEo3isrxk2xKSHXID7kAmPMEr/OC/w=; b=q1bGJ2JEjqdnFTxN26ZdLWtUDx 5vR2bGh4J9q1Tb3a0BndbOiTK5faD0HU/c1roTqv+eBOwh4qeePV2UYRJxT1De5L0fUZfQkzNcHCC vI6f9mo9w5qwjFY9S4babxxNZQJmZNGJwua3544ZgYs93QX59PGjC1ARhF0gm4SDuhJO+ckTfQvuw v0F69soSxLiMh7wKXN9Jynf2vyZM9r2wlAyVLk7YbIje+wFgIP1qbOuk1Cu+yet4ZOjkO4CtsCBZT +DAkwL7g4Nq9TOoQ9eRNPShT+Rx9LYiDa614afDICVZCqs61ChiIW85guWKGh0gUXEO+50/6TI7G5 UmYVfavQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rVRnf-00000006xBL-2Itl; Thu, 01 Feb 2024 07:47:55 +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 1rVRnb-00000006xAd-17U6 for barebox@lists.infradead.org; Thu, 01 Feb 2024 07:47:52 +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 1rVRnW-0007Es-Kd; Thu, 01 Feb 2024 08:47:46 +0100 Received: from [2a0a:edc0:2:b01:1d::c0] (helo=ptx.whiteo.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 1rVRnW-003o54-81; Thu, 01 Feb 2024 08:47:46 +0100 Received: from sha by ptx.whiteo.stw.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1rVRnW-002twk-5h; Thu, 01 Feb 2024 08:47:46 +0100 Date: Thu, 1 Feb 2024 08:47:46 +0100 From: Sascha Hauer To: Stefan Kerkmann Cc: BAREBOX Message-ID: <20240201074746.GH406126@pengutronix.de> References: <20240131-fix-fdt-memory-safety-v1-0-3d3a2c797eec@pengutronix.de> <20240131-fix-fdt-memory-safety-v1-2-3d3a2c797eec@pengutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240131-fix-fdt-memory-safety-v1-2-3d3a2c797eec@pengutronix.de> X-Sent-From: Pengutronix Hildesheim X-URL: http://www.pengutronix.de/ X-Accept-Language: de,en X-Accept-Content-Type: text/plain User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240131_234751_324771_A1E25E8D X-CRM114-Status: GOOD ( 26.30 ) 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=-5.9 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) In the subject: s/ftd/fdt/ 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 > > -- Pengutronix e.K. | | Steuerwalder Str. 21 | http://www.pengutronix.de/ | 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |