From patchwork Mon Oct 12 13:26:47 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 270219 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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 BD6CFC433E7 for ; Mon, 12 Oct 2020 14:03:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7FF10206F4 for ; Mon, 12 Oct 2020 14:03:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602511428; bh=Uqcssya3qJQURCLZ5TZcMKCc+eeib0YtWVFfrFHR1vk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=p9wpDwEZ2v4Oy0kFXUP/nzbLIwbeaevu/3ogskSsUMKv50Vn9dsPGPA/NZRxofLN9 Wrk4DlDPWSPCVQmJUj7oiIzt4LJY2440doF96nNi2fVEdRKG33nO4l8KuKdRVrgHR6 9tNMGLlPJDflutiiVB5372WZwls9iGxd2d/O6Pw4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390436AbgJLODr (ORCPT ); Mon, 12 Oct 2020 10:03:47 -0400 Received: from mail.kernel.org ([198.145.29.99]:39186 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730424AbgJLNgc (ORCPT ); Mon, 12 Oct 2020 09:36:32 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B46452076E; Mon, 12 Oct 2020 13:36:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1602509790; bh=Uqcssya3qJQURCLZ5TZcMKCc+eeib0YtWVFfrFHR1vk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cbjWU33o/WbW+8zviYWmpZjCXLeO+fOQWwOp69Jrs5I7TcLqoaaTI+F8tH2HnmJCq a7BuKqAPPGUK4h35sjPs6ImDT5h5m/poCYK+VIoLrNOA52pIMVn71Bok6/SEo6xfYJ by8Wcd36UDjUPP0kTJyCvMEjWcC7AyqdBNE8FCWs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Giuliano Procida Subject: [PATCH 4.14 31/70] drm/syncobj: Fix drm_syncobj_handle_to_fd refcount leak Date: Mon, 12 Oct 2020 15:26:47 +0200 Message-Id: <20201012132631.677832766@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201012132630.201442517@linuxfoundation.org> References: <20201012132630.201442517@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Giuliano Procida Commit 5fb252cad61f20ae5d5a8b199f6cc4faf6f418e1, a cherry-pick of upstream commit e7cdf5c82f1773c3386b93bbcf13b9bfff29fa31, introduced a refcount imbalance and thus a struct drm_syncobj object leak which can be triggered with DRM_IOCTL_SYNCOBJ_HANDLE_TO_FD. The function drm_syncobj_handle_to_fd first calls drm_syncobj_find which increments the refcount of the object on success. In all of the drm_syncobj_handle_to_fd error paths, the refcount is decremented, but in the success path the refcount should remain at +1 as the struct drm_syncobj now belongs to the newly opened file. Instead, the refcount was incremented again to +2. Fixes: 5fb252cad61f ("drm/syncobj: Stop reusing the same struct file for all syncobj -> fd") Signed-off-by: Giuliano Procida Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/drm_syncobj.c | 1 - 1 file changed, 1 deletion(-) --- a/drivers/gpu/drm/drm_syncobj.c +++ b/drivers/gpu/drm/drm_syncobj.c @@ -355,7 +355,6 @@ static int drm_syncobj_handle_to_fd(stru return PTR_ERR(file); } - drm_syncobj_get(syncobj); fd_install(fd, file); *p_fd = fd;