Commit 5d3ba3aa authored by Heikki Krogerus's avatar Heikki Krogerus Committed by ZhangPeng
Browse files

usb: typec: ucsi: displayport: Fix potential deadlock 

stable inclusion
from stable-v6.6.32
commit 2f95dfb647a8f7789b1d8a806ac89bab1cf1f543
bugzilla: https://gitee.com/openeuler/kernel/issues/IA4MGD

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=2f95dfb647a8f7789b1d8a806ac89bab1cf1f543



--------------------------------

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: default avatarMathias Nyman <mathias.nyman@linux.intel.com>
Fixes: af8622f6 ("usb: typec: ucsi: Support for DisplayPort alt mode")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20240507134316.161999-1-heikki.krogerus@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: default avatarZhangPeng <zhangpeng362@huawei.com>
parent b03000ef

drivers/usb/typec/ucsi/displayport.c

+0 −4
Original line number Diff line number Diff line
@@ -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)