Commit 8ae2f2b0 authored by Reka Norman's avatar Reka Norman Committed by Jiri Kosina
Browse files

HID: intel-ish-hid: ipc: Fix potential use-after-free in work function 



When a reset notify IPC message is received, the ISR schedules a work
function and passes the ISHTP device to it via a global pointer
ishtp_dev. If ish_probe() fails, the devm-managed device resources
including ishtp_dev are freed, but the work is not cancelled, causing a
use-after-free when the work function tries to access ishtp_dev. Use
devm_work_autocancel() instead, so that the work is automatically
cancelled if probe fails.

Signed-off-by: default avatarReka Norman <rekanorman@chromium.org>
Acked-by: default avatarSrinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: default avatarJiri Kosina <jkosina@suse.cz>
parent db50f7a3

drivers/hid/intel-ish-hid/ipc/ipc.c

+8 −1
Original line number Diff line number Diff line
@@ -5,6 +5,7 @@ 
 * Copyright (c) 2014-2016, Intel Corporation.

 */



#include <linux/devm-helpers.h>

#include <linux/sched.h>

#include <linux/spinlock.h>

#include <linux/delay.h>
@@ -621,7 +622,6 @@ static void recv_ipc(struct ishtp_device *dev, uint32_t doorbell_val) 
	case MNG_RESET_NOTIFY:

		if (!ishtp_dev) {

			ishtp_dev = dev;

			INIT_WORK(&fw_reset_work, fw_reset_work_fn);

		}

		schedule_work(&fw_reset_work);

		break;
@@ -940,6 +940,7 @@ struct ishtp_device *ish_dev_init(struct pci_dev *pdev) 
{

	struct ishtp_device *dev;

	int	i;

	int	ret;



	dev = devm_kzalloc(&pdev->dev,

			   sizeof(struct ishtp_device) + sizeof(struct ish_hw),
@@ -975,6 +976,12 @@ struct ishtp_device *ish_dev_init(struct pci_dev *pdev) 
		list_add_tail(&tx_buf->link, &dev->wr_free_list);

	}



	ret = devm_work_autocancel(&pdev->dev, &fw_reset_work, fw_reset_work_fn);

	if (ret) {

		dev_err(dev->devc, "Failed to initialise FW reset work\n");

		return NULL;

	}



	dev->ops = &ish_hw_ops;

	dev->devc = &pdev->dev;

	dev->mtu = IPC_PAYLOAD_SIZE - sizeof(struct ishtp_msg_hdr);