From patchwork Sun Dec 27 11:46:44 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Defang Bo X-Patchwork-Id: 352579 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=-15.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,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 1A839C433E6 for ; Sun, 27 Dec 2020 12:23:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D061A207E8 for ; Sun, 27 Dec 2020 12:23:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726172AbgL0MXE (ORCPT ); Sun, 27 Dec 2020 07:23:04 -0500 Received: from m15111.mail.126.com ([220.181.15.111]:59500 "EHLO m15111.mail.126.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726039AbgL0MXD (ORCPT ); Sun, 27 Dec 2020 07:23:03 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=From:Subject:Date:Message-Id; bh=EeQ64OxSk6Lgpq0NYh 2skNXNACqermCASGbXx4NCP20=; b=X7ybtLWimHZ3JuDheqddp0wiFF8Z0SSmAR iUZ+JJ8R0rW7n/kYvDwyqKndnw+6BdUQEXA8St6EQfxegk9GHbwEYw3NQDQj+lo+ fPp32biGou67XoCOzYxSymhQm5iLw8KS+7byKE12kMhjHZYgRZ32r6ZVbtN6ASQP Mpl9sfCSg= Received: from localhost.localdomain (unknown [36.112.86.14]) by smtp1 (Coremail) with SMTP id C8mowADX3DwsdOhf1VsQNA--.25891S2; Sun, 27 Dec 2020 19:46:53 +0800 (CST) From: Defang Bo To: airlied@linux.ie, daniel@ffwll.ch, sumit.semwal@linaro.org Cc: alexander.deucher@amd.com, christian.koenig@amd.com, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linaro-mm-sig@lists.linaro.org, Defang Bo Subject: [PATCH] drm/amd:avoid null pointer dereference when dev is not bound Date: Sun, 27 Dec 2020 19:46:44 +0800 Message-Id: <1609069604-3949767-1-git-send-email-bodefang@126.com> X-Mailer: git-send-email 2.7.4 X-CM-TRANSID: C8mowADX3DwsdOhf1VsQNA--.25891S2 X-Coremail-Antispam: 1Uf129KBjvdXoW7Jw4rAryUuF1xKr1rtr1xAFb_yoWfurc_ur W5ZFykXr43AF1vqr1ayr4fZasrtFnY9FWkWrn3ta9ayry3Z3yUZrWqqF10g3WxWa1xCF1D Z3Wqgr4Sy3ZF9jkaLaAFLSUrUUUUUb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU1kR63UUUUU== X-Originating-IP: [36.112.86.14] X-CM-SenderInfo: pergvwxdqjqiyswou0bp/1tbiYw0I11x5bWrfHwAAsT Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org [Why] Similar to commit<0fa375e6>. If amdgpu_switcheroo_can_switch access the drm_device when dev is not bound, a null pointer dereference can happen. [How] Add sanity checks to prevent it. Signed-off-by: Defang Bo --- drivers/gpu/drm/amd/amdgpu/amdgpu_device.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c index 37da353..f70e528 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_device.c @@ -1439,6 +1439,9 @@ static void amdgpu_switcheroo_set_state(struct pci_dev *pdev, static bool amdgpu_switcheroo_can_switch(struct pci_dev *pdev) { struct drm_device *dev = pci_get_drvdata(pdev); + + if (!dev) + return false; /* * FIXME: open_count is protected by drm_global_mutex but that would lead to