From mboxrd@z Thu Jan 1 00:00:00 1970 Delivery-date: Wed, 19 Feb 2025 17:51:21 +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 1tknIA-004Nt4-0m for lore@lore.pengutronix.de; Wed, 19 Feb 2025 17:51:21 +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 1tknI9-00068W-3H for lore@pengutronix.de; Wed, 19 Feb 2025 17:51:21 +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=UoIz7/fJtldG72Ed8EmFYgzpJsM9bQiX2jl7kFgdWBE=; b=WohA+M1YhzNzMPR2f3IONNSHJh I1hFkuIBkFKpOOaxDdKsUY/qXsVZI3WEoLWJCZuMzIfltzTP89fILYTbYJn4xLIJl5/3/fW1Fq4Fe 5klK/2ZtX3twwGA9UvQIGV6z0++rGKeSBWTOhd/7Xl/uiGUX3WgHi+LiahbCT/F/s0ALiq1sEGB3a J55LEirXKxsuJZo32KJHSCQt+EKgLwvVUWgSVcjIBZ/3fTmwCrJZyiix6Vk5mfDILDznpwz14nZAl KyqxK+nnMR1xicsmhoyq/DOmP/6KPaEmGB5zN6kiz8CrScWR6ITdfgxnECvm2S/PmigAHDwtOOnms VxsjzxRA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tknHl-0000000DwI0-0lSK; Wed, 19 Feb 2025 16:50:57 +0000 Received: from metis.whiteo.stw.pengutronix.de ([2a0a:edc0:2:b01:1d::104]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tknHi-0000000DwH3-39h0 for barebox@lists.infradead.org; Wed, 19 Feb 2025 16:50:56 +0000 Received: from ptz.office.stw.pengutronix.de ([2a0a:edc0:0:900:1d::77] helo=[127.0.0.1]) by metis.whiteo.stw.pengutronix.de with esmtp (Exim 4.92) (envelope-from ) id 1tknHh-000624-IV; Wed, 19 Feb 2025 17:50:53 +0100 Message-ID: <0b07c033-131d-4403-8709-0e31bce0617f@pengutronix.de> Date: Wed, 19 Feb 2025 17:50:53 +0100 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird To: Sascha Hauer , Barebox List Cc: Jonathan Bar Or References: <20250219141844.1912413-1-s.hauer@pengutronix.de> <20250219141844.1912413-3-s.hauer@pengutronix.de> Content-Language: en-US From: Ahmad Fatoum In-Reply-To: <20250219141844.1912413-3-s.hauer@pengutronix.de> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250219_085054_795348_EC3A43B2 X-CRM114-Status: GOOD ( 18.68 ) 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=-5.3 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: Re: [PATCH 2/5] CVE-2025-26724: fs: cramfs: fix malloc(size + constant) buffer overflow issues 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) On 19.02.25 15:18, Sascha Hauer wrote: > The pattern malloc(size + constant) is dangerous when size can be > manipulated by an attacker. In that case 'size' can be manipulated > in a way that 'size + constant' is 0 due to integer overflow. The > result is a zero sized buffer to which is then data written to. > > Avoid this by using size_add() instead. For those unfamiliar with size_add(), it does a saturation addition and thus xzalloc() will fail as it's impossible to allocate SIZE_MAX bytes. > > Reported-by: Jonathan Bar Or > Signed-off-by: Sascha Hauer Reviewed-by: Ahmad Fatoum Thanks, Ahmad > --- > fs/cramfs/cramfs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/fs/cramfs/cramfs.c b/fs/cramfs/cramfs.c > index e554ebef6f..641a6d2b05 100644 > --- a/fs/cramfs/cramfs.c > +++ b/fs/cramfs/cramfs.c > @@ -423,7 +423,7 @@ static const char *cramfs_get_link(struct dentry *dentry, struct inode *inode) > { > int ret; > > - inode->i_link = xzalloc(inode->i_size + 1); > + inode->i_link = xzalloc(size_add(inode->i_size, 1)); > > ret = cramfs_read_file(inode, 0, inode->i_link, inode->i_size); > if (ret < 0) -- 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 |