From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sasha Levin Subject: [PATCH AUTOSEL 4.14 063/123] HID: intel-ish-hid: avoid binding wrong ishtp_cl_device Date: Wed, 27 Mar 2019 14:15:27 -0400 Message-ID: <20190327181628.15899-63-sashal@kernel.org> References: <20190327181628.15899-1-sashal@kernel.org> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <20190327181628.15899-1-sashal@kernel.org> Sender: linux-kernel-owner@vger.kernel.org To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Hong Liu , Jiri Kosina , Sasha Levin , linux-input@vger.kernel.org List-Id: linux-input@vger.kernel.org From: Hong Liu [ Upstream commit 0d28f49412405d87d3aae83da255070a46e67627 ] When performing a warm reset in ishtp bus driver, the ishtp_cl_device will not be removed, its fw_client still points to the already freed ishtp_device.fw_clients array. Later after driver finishing ishtp client enumeration, this dangling pointer may cause driver to bind the wrong ishtp_cl_device to the new client, causing wrong callback to be called for messages intended for the new client. This helps in development of firmware where frequent switching of firmwares is required without Linux reboot. Signed-off-by: Hong Liu Tested-by: Hongyan Song Acked-by: Srinivas Pandruvada Signed-off-by: Jiri Kosina Signed-off-by: Sasha Levin --- drivers/hid/intel-ish-hid/ishtp/bus.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/hid/intel-ish-hid/ishtp/bus.c b/drivers/hid/intel-ish-hid/ishtp/bus.c index 2623a567ffba..f546635e9ac9 100644 --- a/drivers/hid/intel-ish-hid/ishtp/bus.c +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c @@ -623,7 +623,8 @@ int ishtp_cl_device_bind(struct ishtp_cl *cl) spin_lock_irqsave(&cl->dev->device_list_lock, flags); list_for_each_entry(cl_device, &cl->dev->device_list, device_link) { - if (cl_device->fw_client->client_id == cl->fw_client_id) { + if (cl_device->fw_client && + cl_device->fw_client->client_id == cl->fw_client_id) { cl->device = cl_device; rv = 0; break; @@ -683,6 +684,7 @@ void ishtp_bus_remove_all_clients(struct ishtp_device *ishtp_dev, spin_lock_irqsave(&ishtp_dev->device_list_lock, flags); list_for_each_entry_safe(cl_device, n, &ishtp_dev->device_list, device_link) { + cl_device->fw_client = NULL; if (warm_reset && cl_device->reference_count) continue; -- 2.19.1