From mboxrd@z Thu Jan 1 00:00:00 1970 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 80E8AC83F26 for ; Sun, 27 Aug 2023 17:57:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230050AbjH0R42 (ORCPT ); Sun, 27 Aug 2023 13:56:28 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37586 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229881AbjH0Rzz (ORCPT ); Sun, 27 Aug 2023 13:55:55 -0400 Received: from madras.collabora.co.uk (madras.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e5ab]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6A2F312E for ; Sun, 27 Aug 2023 10:55:53 -0700 (PDT) Received: from workpc.. (109-252-153-31.dynamic.spd-mgts.ru [109.252.153.31]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: dmitry.osipenko) by madras.collabora.co.uk (Postfix) with ESMTPSA id 5CC4E6601F5E; Sun, 27 Aug 2023 18:55:50 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=collabora.com; s=mail; t=1693158952; bh=gy3uY3hU4b+eh09ptffZWw3oZWkfKZfl7NLeYKVx5Jk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NlxF6k3TIR0ANfnT1O22Rl0rf3oPZv1weESs2Xw2/PCHO1BIIEGilAghh23PVab9g yUzsPIJ4UgqraCOf2hFv5n5GU9HDhH9pu4ar/JY8JOuX+azdt2qVHZiHrU5avMAfia 6tIEZlJie1qXJdIUMK4dCzImzgdkAfWqGUyAoDYEn+VIcbStfa15X/TFQD3zPsLE49 2zE3Vx8gv/4lsz0/GVdpeBq4ySaXqZzUT9z/BUmeIIfC/aW1Lke+FWYAuuC6D/EpTu WmdB0wttRAjfK/huSn7IT+dKaDX4K0q4xs5cQJvwy7HWnCSqPbi/83REQfHNFOP0/Q l+sd/EkJo4Gwg== From: Dmitry Osipenko To: David Airlie , Gerd Hoffmann , Gurchetan Singh , Chia-I Wu , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , =?UTF-8?q?Christian=20K=C3=B6nig?= , Qiang Yu , Steven Price , Boris Brezillon , Emma Anholt , Melissa Wen , Will Deacon , Peter Zijlstra , Boqun Feng , Mark Rutland Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, kernel@collabora.com, virtualization@lists.linux-foundation.org, intel-gfx@lists.freedesktop.org Subject: [PATCH v15 01/23] drm/shmem-helper: Fix UAF in error path when freeing SGT of imported GEM Date: Sun, 27 Aug 2023 20:54:27 +0300 Message-ID: <20230827175449.1766701-2-dmitry.osipenko@collabora.com> X-Mailer: git-send-email 2.41.0 In-Reply-To: <20230827175449.1766701-1-dmitry.osipenko@collabora.com> References: <20230827175449.1766701-1-dmitry.osipenko@collabora.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Freeing drm-shmem GEM right after creating it using drm_gem_shmem_prime_import_sg_table() frees SGT of the imported dma-buf and then dma-buf frees this SGT second time. The v3d_prime_import_sg_table() is example of a error code path where dma-buf's SGT is freed by drm-shmem and then it's freed second time by dma_buf_unmap_attachment() in drm_gem_prime_import_dev(). Add drm-shmem GEM flag telling that this is imported SGT shall not be treated as own SGT, fixing the use-after-free bug. Cc: stable@vger.kernel.org Fixes: 2194a63a818d ("drm: Add library for shmem backed GEM objects") Signed-off-by: Dmitry Osipenko --- drivers/gpu/drm/drm_gem_shmem_helper.c | 3 ++- include/drm/drm_gem_shmem_helper.h | 7 +++++++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c index a783d2245599..78d9cf2355a5 100644 --- a/drivers/gpu/drm/drm_gem_shmem_helper.c +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c @@ -141,7 +141,7 @@ void drm_gem_shmem_free(struct drm_gem_shmem_object *shmem) if (obj->import_attach) { drm_prime_gem_destroy(obj, shmem->sgt); - } else { + } else if (!shmem->imported_sgt) { dma_resv_lock(shmem->base.resv, NULL); drm_WARN_ON(obj->dev, shmem->vmap_use_count); @@ -758,6 +758,7 @@ drm_gem_shmem_prime_import_sg_table(struct drm_device *dev, return ERR_CAST(shmem); shmem->sgt = sgt; + shmem->imported_sgt = true; drm_dbg_prime(dev, "size = %zu\n", size); diff --git a/include/drm/drm_gem_shmem_helper.h b/include/drm/drm_gem_shmem_helper.h index bf0c31aa8fbe..ec70a98a8fe1 100644 --- a/include/drm/drm_gem_shmem_helper.h +++ b/include/drm/drm_gem_shmem_helper.h @@ -73,6 +73,13 @@ struct drm_gem_shmem_object { */ unsigned int vmap_use_count; + /** + * @imported_sgt: + * + * True if SG table belongs to imported dma-buf. + */ + bool imported_sgt : 1; + /** * @pages_mark_dirty_on_put: * -- 2.41.0