From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:56654 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754751AbeDKSlB (ORCPT ); Wed, 11 Apr 2018 14:41:01 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pan Bian , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin Subject: [PATCH 3.18 072/121] [media] cx25840: fix unchecked return values Date: Wed, 11 Apr 2018 20:36:15 +0200 Message-Id: <20180411183500.538216736@linuxfoundation.org> In-Reply-To: <20180411183456.195010921@linuxfoundation.org> References: <20180411183456.195010921@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pan Bian [ Upstream commit 35378ce143071c2a6bad4b59a000e9b9f8f6ea67 ] In functions cx25840_initialize(), cx231xx_initialize(), and cx23885_initialize(), the return value of create_singlethread_workqueue() is used without validation. This may result in NULL dereference and cause kernel crash. This patch fixes it. Signed-off-by: Pan Bian Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/media/i2c/cx25840/cx25840-core.c | 36 ++++++++++++++++++------------- 1 file changed, 21 insertions(+), 15 deletions(-) --- a/drivers/media/i2c/cx25840/cx25840-core.c +++ b/drivers/media/i2c/cx25840/cx25840-core.c @@ -420,11 +420,13 @@ static void cx25840_initialize(struct i2 INIT_WORK(&state->fw_work, cx25840_work_handler); init_waitqueue_head(&state->fw_wait); q = create_singlethread_workqueue("cx25840_fw"); - prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); - queue_work(q, &state->fw_work); - schedule(); - finish_wait(&state->fw_wait, &wait); - destroy_workqueue(q); + if (q) { + prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); + queue_work(q, &state->fw_work); + schedule(); + finish_wait(&state->fw_wait, &wait); + destroy_workqueue(q); + } /* 6. */ cx25840_write(client, 0x115, 0x8c); @@ -631,11 +633,13 @@ static void cx23885_initialize(struct i2 INIT_WORK(&state->fw_work, cx25840_work_handler); init_waitqueue_head(&state->fw_wait); q = create_singlethread_workqueue("cx25840_fw"); - prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); - queue_work(q, &state->fw_work); - schedule(); - finish_wait(&state->fw_wait, &wait); - destroy_workqueue(q); + if (q) { + prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); + queue_work(q, &state->fw_work); + schedule(); + finish_wait(&state->fw_wait, &wait); + destroy_workqueue(q); + } /* Call the cx23888 specific std setup func, we no longer rely on * the generic cx24840 func. @@ -746,11 +750,13 @@ static void cx231xx_initialize(struct i2 INIT_WORK(&state->fw_work, cx25840_work_handler); init_waitqueue_head(&state->fw_wait); q = create_singlethread_workqueue("cx25840_fw"); - prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); - queue_work(q, &state->fw_work); - schedule(); - finish_wait(&state->fw_wait, &wait); - destroy_workqueue(q); + if (q) { + prepare_to_wait(&state->fw_wait, &wait, TASK_UNINTERRUPTIBLE); + queue_work(q, &state->fw_work); + schedule(); + finish_wait(&state->fw_wait, &wait); + destroy_workqueue(q); + } cx25840_std_setup(client);