6.6-stable review patch. If anyone has any objections, please let me know.
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From: Heikki Krogerus heikki.krogerus@linux.intel.com
commit b791a67f68121d69108640d4a3e591d210ffe850 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 mathias.nyman@linux.intel.com Fixes: af8622f6a585 ("usb: typec: ucsi: Support for DisplayPort alt mode") Cc: stable@vger.kernel.org Signed-off-by: Heikki Krogerus heikki.krogerus@linux.intel.com Link: https://lore.kernel.org/r/20240507134316.161999-1-heikki.krogerus@linux.inte... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/typec/ucsi/displayport.c | 4 ---- 1 file changed, 4 deletions(-)
--- a/drivers/usb/typec/ucsi/displayport.c +++ b/drivers/usb/typec/ucsi/displayport.c @@ -275,8 +275,6 @@ static void ucsi_displayport_work(struct 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 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)