usb: typec: ucsi: displayport: Fix potential deadlock

commit b791a67 upstream. The function ucsi_displayport_work() does not access the connector, so it also must not acquire the connector lock. This fixes a potential deadlock scenario: ucsi_displayport_work() -> lock(&con->lock) typec_altmode_vdm() dp_altmode_vdm() dp_altmode_work() typec_altmode_enter() ucsi_displayport_enter() -> lock(&con->lock) Reported-by: Mathias Nyman <[email protected]> Fixes: af8622f ("usb: typec: ucsi: Support for DisplayPort alt mode") Cc: [email protected] Signed-off-by: Heikki Krogerus <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
frank-w · May 25, 2024 · 1768f29 · 1768f29
1 parent ddbcd7d
commit 1768f29
Showing 1 changed file with 0 additions and 4 deletions.
diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c
@@ -275,8 +275,6 @@ static void ucsi_displayport_work(struct work_struct *work)
 	struct ucsi_dp *dp = container_of(work, struct ucsi_dp, work);
 	int ret;
 
-	mutex_lock(&dp->con->lock);
-
 	ret = typec_altmode_vdm(dp->alt, dp->header,
 				dp->vdo_data, dp->vdo_size);
 	if (ret)
@@ -285,8 +283,6 @@ static void ucsi_displayport_work(struct work_struct *work)
 	dp->vdo_data = NULL;
 	dp->vdo_size = 0;
 	dp->header = 0;
-
-	mutex_unlock(&dp->con->lock);
 }
 
 void ucsi_displayport_remove_partner(struct typec_altmode *alt)