From nobody Tue Sep 16 18:07:51 2025 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 38A9FC3DA7C for ; Fri, 30 Dec 2022 07:28:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234640AbiL3H22 (ORCPT ); Fri, 30 Dec 2022 02:28:28 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:51832 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234590AbiL3H2V (ORCPT ); Fri, 30 Dec 2022 02:28:21 -0500 Received: from m12.mail.163.com (m12.mail.163.com [123.126.96.234]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 09F5018E08 for ; Thu, 29 Dec 2022 23:28:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:Subject:Date:Message-Id:MIME-Version; bh=BZVBV RQVrTSn4BzI4JujaZV4qktmUeRF9eHZ5CKmHQM=; b=gJadKLaWCNs+R5dJcOlvU pXAWaVns4xKQJLjAOu+DCzyNHH7dhJ3pj3HBpKS6uyqCsb9Hz5V5ts2/uazefHoT t+TzH+ipfiNnAwWJ/KJaRUX3DCOcCdjr1SyFCyCIczbjTBIXcwvMrD8tlF5jnqtg Ercxuwa3ZpPBCNZF8HhgUQ= Received: from leanderwang-LC2.localdomain (unknown [111.206.145.21]) by smtp16 (Coremail) with SMTP id MNxpCgCnzzsVk65jw+eMDQ--.25047S2; Fri, 30 Dec 2022 15:28:21 +0800 (CST) From: Zheng Wang To: bskeggs@redhat.com Cc: kherbst@redhat.com, lyude@redhat.com, airlied@gmail.com, hackerzheng666@gmail.com, alex000young@gmail.com, security@kernel.org, daniel@ffwll.ch, dri-devel@lists.freedesktop.org, nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, Zheng Wang Subject: [PATCH] drm/nouveau/mmu: fix Use after Free bug in nvkm_vmm_node_split Date: Fri, 30 Dec 2022 15:27:58 +0800 Message-Id: <20221230072758.443644-1-zyytlz.wz@163.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-CM-TRANSID: MNxpCgCnzzsVk65jw+eMDQ--.25047S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7GF15Gr48ur17XrW5WryxGrg_yoW8JF4rpF 45uryYvryxuF4Ut340vFy8ur90kan2yFWIk34YvasIvwnxZ3y0vFW5AryUGryrZw4xWw1a qr4DGr1fWry5ArJanT9S1TB71UUUUUUqnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0ziaZXrUUUUU= X-Originating-IP: [111.206.145.21] X-CM-SenderInfo: h2113zf2oz6qqrwthudrp/xtbCbxTnU2BbEN8pBAAAsW Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Here is a function call chain. nvkm_vmm_pfn_map->nvkm_vmm_pfn_split_merge->nvkm_vmm_node_split If nvkm_vma_tail return NULL in nvkm_vmm_node_split, it will finally invoke nvkm_vmm_node_merge->nvkm_vmm_node_delete, which will free the vma. However, nvkm_vmm_pfn_map didn't notice that. It goes into next label and UAF happens. Fix it by returning the return-value of nvkm_vmm_node_merge instead of NULL. Signed-off-by: Zheng Wang --- drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c b/drivers/gpu/dr= m/nouveau/nvkm/subdev/mmu/vmm.c index ae793f400ba1..84d6fc87b2e8 100644 --- a/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/mmu/vmm.c @@ -937,8 +937,8 @@ nvkm_vmm_node_split(struct nvkm_vmm *vmm, if (vma->size !=3D size) { struct nvkm_vma *tmp; if (!(tmp =3D nvkm_vma_tail(vma, vma->size - size))) { - nvkm_vmm_node_merge(vmm, prev, vma, NULL, vma->size); - return NULL; + tmp =3D nvkm_vmm_node_merge(vmm, prev, vma, NULL, vma->size); + return tmp; } tmp->part =3D true; nvkm_vmm_node_insert(vmm, tmp); --=20 2.25.1