4.9-stable review patch. If anyone has any objections, please let me know.
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[ 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 hong.liu@intel.com Tested-by: Hongyan Song hongyan.song@intel.com 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/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 256521509d20..0de18c76f8d4 100644 --- a/drivers/hid/intel-ish-hid/ishtp/bus.c +++ b/drivers/hid/intel-ish-hid/ishtp/bus.c @@ -628,7 +628,8 @@ 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; @@ -688,6 +689,7 @@ 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;