[PATCH AUTOSEL 6.2 05/30] HID: intel-ish-hid: ipc: Fix potential use-after-free in work function

Sasha Levin
2023-03-20T00:53:35Z

From: Reka Norman <rekanorman@chromium.org>

[ Upstream commit 8ae2f2b0a28416ed2f6d8478ac8b9f7862f36785 ]

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: Reka Norman <rekanorman@chromium.org>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/hid/intel-ish-hid/ipc/ipc.c | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-ish-hid/ipc/ipc.c
index 15e14239af829..a49c6affd7c4c 100644
--- a/drivers/hid/intel-ish-hid/ipc/ipc.c
+++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
@@ -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);
--
2.39.2