ucsi_init() which runs from a workqueue sets ucsi->connector and on an error will clear it again.
ucsi->connector gets dereferenced by ucsi_resume(), this checks for ucsi->connector being NULL in case ucsi_init() has not finished yet; or in case ucsi_init() has failed.
ucsi_init() setting ucsi->connector and then clearing it again on an error creates a race where the check in ucsi_resume() may pass, only to have ucsi->connector free-ed underneath it when ucsi_init() hits an error.
Fix this race by making ucsi_init() store the connector array in a local variable and only assign it to ucsi->connector on success.
Fixes: bdc62f2bae8f ("usb: typec: ucsi: Simplified registration and I/O API") Cc: stable@vger.kernel.org Reviewed-by: Heikki Krogerus heikki.krogerus@linux.intel.com Signed-off-by: Hans de Goede hdegoede@redhat.com --- Changes in v4: - Rebase on top of v6.3-rc1
Changes in v3: - Assign connector[i].index before calling ucsi_register_port() instead of passing i to ucsi_register_port() --- drivers/usb/typec/ucsi/ucsi.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)
diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 0623861c597b..8d1baf28df55 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1125,12 +1125,11 @@ static struct fwnode_handle *ucsi_find_fwnode(struct ucsi_connector *con) return NULL; }
-static int ucsi_register_port(struct ucsi *ucsi, int index) +static int ucsi_register_port(struct ucsi *ucsi, struct ucsi_connector *con) { struct usb_power_delivery_desc desc = { ucsi->cap.pd_version}; struct usb_power_delivery_capabilities_desc pd_caps; struct usb_power_delivery_capabilities *pd_cap; - struct ucsi_connector *con = &ucsi->connector[index]; struct typec_capability *cap = &con->typec_cap; enum typec_accessory *accessory = cap->accessory; enum usb_role u_role = USB_ROLE_NONE; @@ -1151,7 +1150,6 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) init_completion(&con->complete); mutex_init(&con->lock); INIT_LIST_HEAD(&con->partner_tasks); - con->num = index + 1; con->ucsi = ucsi;
cap->fwnode = ucsi_find_fwnode(con); @@ -1328,7 +1326,7 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) */ static int ucsi_init(struct ucsi *ucsi) { - struct ucsi_connector *con; + struct ucsi_connector *con, *connector; u64 command, ntfy; int ret; int i; @@ -1359,16 +1357,16 @@ static int ucsi_init(struct ucsi *ucsi) }
/* Allocate the connectors. Released in ucsi_unregister() */ - ucsi->connector = kcalloc(ucsi->cap.num_connectors + 1, - sizeof(*ucsi->connector), GFP_KERNEL); - if (!ucsi->connector) { + connector = kcalloc(ucsi->cap.num_connectors + 1, sizeof(*connector), GFP_KERNEL); + if (!connector) { ret = -ENOMEM; goto err_reset; }
/* Register all connectors */ for (i = 0; i < ucsi->cap.num_connectors; i++) { - ret = ucsi_register_port(ucsi, i); + connector[i].num = i + 1; + ret = ucsi_register_port(ucsi, &connector[i]); if (ret) goto err_unregister; } @@ -1380,11 +1378,12 @@ static int ucsi_init(struct ucsi *ucsi) if (ret < 0) goto err_unregister;
+ ucsi->connector = connector; ucsi->ntfy = ntfy; return 0;
err_unregister: - for (con = ucsi->connector; con->port; con++) { + for (con = connector; con->port; con++) { ucsi_unregister_partner(con); ucsi_unregister_altmodes(con, UCSI_RECIPIENT_CON); ucsi_unregister_port_psy(con); @@ -1400,10 +1399,7 @@ static int ucsi_init(struct ucsi *ucsi) typec_unregister_port(con->port); con->port = NULL; } - - kfree(ucsi->connector); - ucsi->connector = NULL; - + kfree(connector); err_reset: memset(&ucsi->cap, 0, sizeof(ucsi->cap)); ucsi_reset_ppm(ucsi);