From nobody Thu Nov 6 06:26:54 2025 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zohomail.com; dkim=fail; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1539314817037447.9521801488652; Thu, 11 Oct 2018 20:26:57 -0700 (PDT) Received: from localhost ([::1]:38062 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAo6B-0004Wk-F8 for importer@patchew.org; Thu, 11 Oct 2018 23:26:47 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:60943) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gAo49-0003FZ-U3 for qemu-devel@nongnu.org; Thu, 11 Oct 2018 23:24:42 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gAo49-0007Wt-45 for qemu-devel@nongnu.org; Thu, 11 Oct 2018 23:24:41 -0400 Received: from ozlabs.org ([2401:3900:2:1::2]:47171) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1gAo48-0007VD-EG; Thu, 11 Oct 2018 23:24:41 -0400 Received: by ozlabs.org (Postfix, from userid 1007) id 42WY9J5ck4z9s7h; Fri, 12 Oct 2018 14:24:36 +1100 (AEDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gibson.dropbear.id.au; s=201602; t=1539314676; bh=DwKRY85D9wNWBqqddQA3JGNRfzA/y93GnlBororTveU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PF11ub0yuptIco48saP7aAIop8L56JHRArajWY4FRAnaQf1IoFBTrR4jMu22W3yh9 N/ZDn4B/c2x2JWjBrP0KQxfBPeC3aG70MVg4FVBD63n4oXKu3NS7eey3YnwtWi2Hkd AraAuC+d/BKIYsePzQXje16QzXhEH58VRtNro3gk= From: David Gibson To: dhildenb@redhat.com, imammedo@redhat.com, ehabkost@redhat.com Date: Fri, 12 Oct 2018 14:24:28 +1100 Message-Id: <20181012032431.32693-3-david@gibson.dropbear.id.au> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20181012032431.32693-1-david@gibson.dropbear.id.au> References: <20181012032431.32693-1-david@gibson.dropbear.id.au> X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 2401:3900:2:1::2 Subject: [Qemu-devel] [RFC 2/5] virtio-balloon: Corrections to address verification X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pbonzini@redhat.com, David Gibson , qemu-ppc@nongnu.org, qemu-devel@nongnu.org, mst@redhat.com Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) X-ZohoMail: RDKM_2 RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" The virtio-balloon device's verification of the address given to it by the guest has a number of faults: * The addresses here are guest physical addresses, which should be 'hwaddr' rather than 'ram_addr_t' (the distinction is admittedly pretty subtle and confusing) * We don't check for section.mr being NULL, which is the main way that memory_region_find() reports basic failures. We really need to check that before looking at any other section fields, because memory_region_find() doesn't initialize them on the failure path * We're passing a length of '1' to memory_region_find(), but really the guest is requesting that we put the entire page into the balloon, so it makes more sense to call it with BALLOON_PAGE_SIZE Signed-off-by: David Gibson Reviewed-by: David Hildenbrand --- hw/virtio/virtio-balloon.c | 17 ++++++++++------- 1 file changed, 10 insertions(+), 7 deletions(-) diff --git a/hw/virtio/virtio-balloon.c b/hw/virtio/virtio-balloon.c index 6ec4bcf4e1..e8611aab0e 100644 --- a/hw/virtio/virtio-balloon.c +++ b/hw/virtio/virtio-balloon.c @@ -221,17 +221,20 @@ static void virtio_balloon_handle_output(VirtIODevice= *vdev, VirtQueue *vq) } =20 while (iov_to_buf(elem->out_sg, elem->out_num, offset, &pfn, 4) = =3D=3D 4) { - ram_addr_t pa; - ram_addr_t addr; + hwaddr pa; + hwaddr addr; int p =3D virtio_ldl_p(vdev, &pfn); =20 - pa =3D (ram_addr_t) p << VIRTIO_BALLOON_PFN_SHIFT; + pa =3D (hwaddr) p << VIRTIO_BALLOON_PFN_SHIFT; offset +=3D 4; =20 - /* FIXME: remove get_system_memory(), but how? */ - section =3D memory_region_find(get_system_memory(), pa, 1); - if (!int128_nz(section.size) || - !memory_region_is_ram(section.mr) || + section =3D memory_region_find(get_system_memory(), pa, + BALLOON_PAGE_SIZE); + if (!section.mr) { + trace_virtio_balloon_bad_addr(pa); + continue; + } + if (!memory_region_is_ram(section.mr) || memory_region_is_rom(section.mr) || memory_region_is_romd(section.mr)) { trace_virtio_balloon_bad_addr(pa); --=20 2.17.1