From: Mayank Rana mrana@codeaurora.org
If ucsi_init() fails for some reason (e.g. ucsi_register_port() fails or general communication failure to the PPM), particularly at any point after the GET_CAPABILITY command had been issued, this results in unwinding the initialization and returning an error. However the ucsi structure's ucsi_capability member retains its current value, including likely a non-zero num_connectors. And because ucsi_init() itself is done in a workqueue a UCSI interface driver will be unaware that it failed and may think the ucsi_register() call was completely successful. Later, if ucsi_unregister() is called, due to this stale ucsi->cap value it would try to access the items in the ucsi->connector array which might not be in a proper state or not even allocated at all and results in NULL or invalid pointer dereference.
Fix this by clearing the ucsi->cap value to 0 during the error path of ucsi_init() in order to prevent a later ucsi_unregister() from entering the connector cleanup loop.
Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface") Cc: stable@vger.kernel.org Signed-off-by: Mayank Rana mrana@codeaurora.org Signed-off-by: Jack Pham jackp@codeaurora.org --- drivers/usb/typec/ucsi/ucsi.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index b433169ef6fa..b7d104c80d85 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1253,6 +1253,7 @@ static int ucsi_init(struct ucsi *ucsi) }
err_reset: + memset(&ucsi->cap, 0, sizeof(ucsi->cap)); ucsi_reset_ppm(ucsi); err: return ret;
On Wed, Jun 09, 2021 at 12:35:35AM -0700, Jack Pham wrote:
From: Mayank Rana mrana@codeaurora.org
If ucsi_init() fails for some reason (e.g. ucsi_register_port() fails or general communication failure to the PPM), particularly at any point after the GET_CAPABILITY command had been issued, this results in unwinding the initialization and returning an error. However the ucsi structure's ucsi_capability member retains its current value, including likely a non-zero num_connectors. And because ucsi_init() itself is done in a workqueue a UCSI interface driver will be unaware that it failed and may think the ucsi_register() call was completely successful. Later, if ucsi_unregister() is called, due to this stale ucsi->cap value it would try to access the items in the ucsi->connector array which might not be in a proper state or not even allocated at all and results in NULL or invalid pointer dereference.
Fix this by clearing the ucsi->cap value to 0 during the error path of ucsi_init() in order to prevent a later ucsi_unregister() from entering the connector cleanup loop.
Fixes: c1b0bc2dabfa ("usb: typec: Add support for UCSI interface") Cc: stable@vger.kernel.org Signed-off-by: Mayank Rana mrana@codeaurora.org Signed-off-by: Jack Pham jackp@codeaurora.org
Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com
drivers/usb/typec/ucsi/ucsi.c | 1 + 1 file changed, 1 insertion(+)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index b433169ef6fa..b7d104c80d85 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1253,6 +1253,7 @@ static int ucsi_init(struct ucsi *ucsi) } err_reset:
- memset(&ucsi->cap, 0, sizeof(ucsi->cap)); ucsi_reset_ppm(ucsi);
err: return ret; -- 2.24.0
linux-stable-mirror@lists.linaro.org
-
Heikki Krogerus -
Jack Pham