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 42B67C4332F for ; Wed, 23 Nov 2022 09:23:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237502AbiKWJXr (ORCPT ); Wed, 23 Nov 2022 04:23:47 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36496 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S237503AbiKWJXJ (ORCPT ); Wed, 23 Nov 2022 04:23:09 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DE03210CEAD for ; Wed, 23 Nov 2022 01:22:16 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 7A95661B44 for ; Wed, 23 Nov 2022 09:22:16 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 179EEC433D7; Wed, 23 Nov 2022 09:22:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669195335; bh=ljU7IhwUlLHS09gVDokkGLxdk/mB7kUBubcpowL28jM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=tr1bCfmpRt/VqNpmXuK52LPjqe2wI/vd17ESyx6ueYakkFLw8gIZleQb3MWW4n/7t iSQNsGXvoi/8E6ihy8Jddvqvvf1y1rTrmZ7XTnqQJEc2jMnWUb7mGPT5n7ImuZgcbo n8MwuNYRaBbnNJ4pDyaGqXyVmSS36h4FyyLqFcsQ= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Shang XiaoJing , Lyude Paul , Sasha Levin Subject: [PATCH 5.10 054/149] drm: Fix potential null-ptr-deref in drm_vblank_destroy_worker() Date: Wed, 23 Nov 2022 09:50:37 +0100 Message-Id: <20221123084559.866757491@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221123084557.945845710@linuxfoundation.org> References: <20221123084557.945845710@linuxfoundation.org> User-Agent: quilt/0.67 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Shang XiaoJing [ Upstream commit 4979524f5a2a8210e87fde2f642b0dc060860821 ] drm_vblank_init() call drmm_add_action_or_reset() with drm_vblank_init_release() as action. If __drmm_add_action() failed, will directly call drm_vblank_init_release() with the vblank whose worker is NULL. As the resule, a null-ptr-deref will happen in kthread_destroy_worker(). Add the NULL check before calling drm_vblank_destroy_worker(). BUG: null-ptr-deref KASAN: null-ptr-deref in range [0x0000000000000068-0x000000000000006f] CPU: 5 PID: 961 Comm: modprobe Not tainted 6.0.0-11331-gd465bff130bf-dirty RIP: 0010:kthread_destroy_worker+0x25/0xb0 Call Trace: drm_vblank_init_release+0x124/0x220 [drm] ? drm_crtc_vblank_restore+0x8b0/0x8b0 [drm] __drmm_add_action_or_reset+0x41/0x50 [drm] drm_vblank_init+0x282/0x310 [drm] vkms_init+0x35f/0x1000 [vkms] ? 0xffffffffc4508000 ? lock_is_held_type+0xd7/0x130 ? __kmem_cache_alloc_node+0x1c2/0x2b0 ? lock_is_held_type+0xd7/0x130 ? 0xffffffffc4508000 do_one_initcall+0xd0/0x4f0 ... do_syscall_64+0x35/0x80 entry_SYSCALL_64_after_hwframe+0x46/0xb0 Fixes: 5e6c2b4f9161 ("drm/vblank: Add vblank works") Signed-off-by: Shang XiaoJing Reviewed-by: Lyude Paul Signed-off-by: Lyude Paul Link: https://patchwork.freedesktop.org/patch/msgid/20221101070716.9189-3-shangxiaojing@huawei.com Signed-off-by: Sasha Levin --- drivers/gpu/drm/drm_internal.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h index f80e0f28087d..41efe40bc70f 100644 --- a/drivers/gpu/drm/drm_internal.h +++ b/drivers/gpu/drm/drm_internal.h @@ -116,7 +116,8 @@ static inline void drm_vblank_flush_worker(struct drm_vblank_crtc *vblank) static inline void drm_vblank_destroy_worker(struct drm_vblank_crtc *vblank) { - kthread_destroy_worker(vblank->worker); + if (vblank->worker) + kthread_destroy_worker(vblank->worker); } int drm_vblank_worker_init(struct drm_vblank_crtc *vblank); -- 2.35.1