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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2F0C6C433DF for ; Mon, 8 Jun 2020 23:11:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 10D0E20C09 for ; Mon, 8 Jun 2020 23:11:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591657885; bh=kntZHaADtqmXEkROzUlLhxaIDHYMV/qGZ2kMk2G8Nlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=aqPfkyqVVUkeho0chFWNnyyXYt86iG7NapCzYo83zmRPywqvgQAPv9ihuoZ12GY3v CpUGaYUSSLKnwbg6H10sFKCGrgE3DWHtqADNzkM9nnYXfg4OiSY04V2WRXNnGpncIW XLGAhXOHqPdXXKKqJoYSQ4NqCUAnp1rDvyl6hxEE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728044AbgFHXLW (ORCPT ); Mon, 8 Jun 2020 19:11:22 -0400 Received: from mail.kernel.org ([198.145.29.99]:55632 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728516AbgFHXJt (ORCPT ); Mon, 8 Jun 2020 19:09:49 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B89B020B80; Mon, 8 Jun 2020 23:09:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1591657788; bh=kntZHaADtqmXEkROzUlLhxaIDHYMV/qGZ2kMk2G8Nlk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Eli+0q8+23VI6xuqdkBZEVpE/REEAaazVpMc7EqhQ5oI98Y8jlA4l71ACC46kRyW2 uTSlTiRkgJTrC/h9OeQMg2q3WxbfTeJoAaKb3ulQ8LZDJSot0NO8Hyqa6DublVQDig cwyyLWQE+ueArq82nz2Ept/0QKDo+ZgweM6XjpLU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Ezequiel Garcia , syzbot+e3372a2afe1e7ef04bc7@syzkaller.appspotmail.com, Rodrigo Siqueira , Rodrigo Siqueira , Sasha Levin , dri-devel@lists.freedesktop.org Subject: [PATCH AUTOSEL 5.7 169/274] drm/vkms: Hold gem object while still in-use Date: Mon, 8 Jun 2020 19:04:22 -0400 Message-Id: <20200608230607.3361041-169-sashal@kernel.org> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20200608230607.3361041-1-sashal@kernel.org> References: <20200608230607.3361041-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Ezequiel Garcia [ Upstream commit 0ea2ea42b31abc1141f2fd3911f952a97d401fcb ] We need to keep the reference to the drm_gem_object until the last access by vkms_dumb_create. Therefore, the put the object after it is used. This fixes a use-after-free issue reported by syzbot. While here, change vkms_gem_create() symbol to static. Reported-and-tested-by: syzbot+e3372a2afe1e7ef04bc7@syzkaller.appspotmail.com Signed-off-by: Ezequiel Garcia Reviewed-by: Rodrigo Siqueira Signed-off-by: Rodrigo Siqueira Link: https://patchwork.freedesktop.org/patch/msgid/20200427214405.13069-1-ezequiel@collabora.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/vkms/vkms_drv.h | 5 ----- drivers/gpu/drm/vkms/vkms_gem.c | 11 ++++++----- 2 files changed, 6 insertions(+), 10 deletions(-) diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index eda04ffba7b1..f4036bb0b9a8 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -117,11 +117,6 @@ struct drm_plane *vkms_plane_init(struct vkms_device *vkmsdev, enum drm_plane_type type, int index); /* Gem stuff */ -struct drm_gem_object *vkms_gem_create(struct drm_device *dev, - struct drm_file *file, - u32 *handle, - u64 size); - vm_fault_t vkms_gem_fault(struct vm_fault *vmf); int vkms_dumb_create(struct drm_file *file, struct drm_device *dev, diff --git a/drivers/gpu/drm/vkms/vkms_gem.c b/drivers/gpu/drm/vkms/vkms_gem.c index 2e01186fb943..c541fec57566 100644 --- a/drivers/gpu/drm/vkms/vkms_gem.c +++ b/drivers/gpu/drm/vkms/vkms_gem.c @@ -97,10 +97,10 @@ vm_fault_t vkms_gem_fault(struct vm_fault *vmf) return ret; } -struct drm_gem_object *vkms_gem_create(struct drm_device *dev, - struct drm_file *file, - u32 *handle, - u64 size) +static struct drm_gem_object *vkms_gem_create(struct drm_device *dev, + struct drm_file *file, + u32 *handle, + u64 size) { struct vkms_gem_object *obj; int ret; @@ -113,7 +113,6 @@ struct drm_gem_object *vkms_gem_create(struct drm_device *dev, return ERR_CAST(obj); ret = drm_gem_handle_create(file, &obj->gem, handle); - drm_gem_object_put_unlocked(&obj->gem); if (ret) return ERR_PTR(ret); @@ -142,6 +141,8 @@ int vkms_dumb_create(struct drm_file *file, struct drm_device *dev, args->size = gem_obj->size; args->pitch = pitch; + drm_gem_object_put_unlocked(gem_obj); + DRM_DEBUG_DRIVER("Created object of size %lld\n", size); return 0; -- 2.25.1