On Wed, 2023-03-29 at 10:03 +0200, Joakim Tjernlund wrote:
From: Hans de Goede hdegoede@redhat.com
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 Link: https://lore.kernel.org/r/20230308154244.722337-3-hdegoede@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org (cherry picked from commit 0482c34ec6f8557e06cd0f8e2d0e20e8ede6a22c) Signed-off-by: Joakim Tjernlund joakim.tjernlund@infinera.com
- This is a dry port to 6.1.x, will be some time before it will be tested.
Tested OK now on 6.1.22 Jocke
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 8cbbb002fefe..086b50968983 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1039,9 +1039,8 @@ 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 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;
@@ -1062,7 +1061,6 @@ 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); @@ -1204,7 +1202,7 @@ 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;
@@ -1235,16 +1233,16 @@ 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]);@@ -1256,11 +1254,12 @@ 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);
@@ -1269,10 +1268,7 @@ 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);