Commit 7e90057f authored Aug 09, 2020 by Hans de Goede Committed by Greg Kroah-Hartman Aug 18, 2020

usb: typec: ucsi: Fix 2 unlocked ucsi_run_command calls



Fix 2 unlocked ucsi_run_command calls:

1. ucsi_handle_connector_change() contains one ucsi_send_command() call,
which takes the ppm_lock for it; and one ucsi_run_command() call which
relies on the caller have taking the ppm_lock.
ucsi_handle_connector_change() does not take the lock, so the
second (ucsi_run_command) calls should also be ucsi_send_command().

2. ucsi_get_pdos() gets called from ucsi_handle_connector_change() which
does not hold the ppm_lock, so it also must use ucsi_send_command().

This commit also adds a WARN_ON(!mutex_is_locked(&ucsi->ppm_lock)); to
ucsi_run_command() to avoid similar problems getting re-introduced in
the future.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20200809141904.4317-3-hdegoede@redhat.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

parent 0ff0705a

drivers/usb/typec/ucsi/ucsi.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -152,6 +152,8 @@ static int ucsi_run_command(struct ucsi *ucsi, u64 command,
		u8 length;
		int ret;

		WARN_ON(!mutex_is_locked(&ucsi->ppm_lock));

		ret = ucsi_exec_command(ucsi, command);
		if (ret < 0)
		return ret;
		@@ -502,7 +504,7 @@ static void ucsi_get_pdos(struct ucsi_connector *con, int is_partner)
		command \|= UCSI_GET_PDOS_PARTNER_PDO(is_partner);
		command \|= UCSI_GET_PDOS_NUM_PDOS(UCSI_MAX_PDOS - 1);
		command \|= UCSI_GET_PDOS_SRC_PDOS;
		ret = ucsi_run_command(ucsi, command, con->src_pdos,
		ret = ucsi_send_command(ucsi, command, con->src_pdos,
		sizeof(con->src_pdos));
		if (ret < 0) {
		dev_err(ucsi->dev, "UCSI_GET_PDOS failed (%d)\n", ret);
		@@ -681,7 +683,7 @@ static void ucsi_handle_connector_change(struct work_struct *work)
		*/
		command = UCSI_GET_CAM_SUPPORTED;
		command \|= UCSI_CONNECTOR_NUMBER(con->num);
		ucsi_run_command(con->ucsi, command, NULL, 0);
		ucsi_send_command(con->ucsi, command, NULL, 0);
		}

		if (con->status.change & UCSI_CONSTAT_PARTNER_CHANGE)

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