diff mbox series

[v5,1/4] usb: typec: ucsi: Fix null pointer dereference in trace

Message ID 20240510201244.2968152-2-jthies@google.com (mailing list archive)
State Accepted
Commit 99516f76db48e1a9d54cdfed63c1babcee4e71a5
Headers show
Series usb: typec: ucsi: Update UCSI alternate mode | expand

Commit Message

Jameson Thies May 10, 2024, 8:12 p.m. UTC 
From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>

ucsi_register_altmode checks IS_ERR for the alt pointer and treats
NULL as valid. When CONFIG_TYPEC_DP_ALTMODE is not enabled,
ucsi_register_displayport returns NULL which causes a NULL pointer
dereference in trace. Rather than return NULL, call
typec_port_register_altmode to register DisplayPort alternate mode
as a non-controllable mode when CONFIG_TYPEC_DP_ALTMODE is not enabled.

Reviewed-by: Benson Leung <bleung@chromium.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
Signed-off-by: Jameson Thies <jthies@google.com>
---
Changes in V5:
- Fixed signed off by line order.

Changes in V4:
- Updated commit message.

Changes in V3:
- Returns typec_port_register_altmode call from
ucsi_register_displayport when CONFIG_TYPEC_DP_ALTMODE is not enabled.
Updated commit message.

Changes in V2:
- Checks for error response from ucsi_register_displayport when
registering DisplayPort alternate mode.

 drivers/usb/typec/ucsi/ucsi.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

Dmitry Baryshkov May 31, 2024, 7:40 p.m. UTC | #1 
On Fri, May 10, 2024 at 08:12:41PM +0000, Jameson Thies wrote:
> From: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> 
> ucsi_register_altmode checks IS_ERR for the alt pointer and treats
> NULL as valid. When CONFIG_TYPEC_DP_ALTMODE is not enabled,
> ucsi_register_displayport returns NULL which causes a NULL pointer
> dereference in trace. Rather than return NULL, call
> typec_port_register_altmode to register DisplayPort alternate mode
> as a non-controllable mode when CONFIG_TYPEC_DP_ALTMODE is not enabled.
> 
> Reviewed-by: Benson Leung <bleung@chromium.org>
> Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> Signed-off-by: Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
> Signed-off-by: Jameson Thies <jthies@google.com>

Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
diff mbox series

Patch

diff --git a/drivers/usb/typec/ucsi/ucsi.h b/drivers/usb/typec/ucsi/ucsi.h
index c4d103db9d0f8..f66224a270bc6 100644
--- a/drivers/usb/typec/ucsi/ucsi.h
+++ b/drivers/usb/typec/ucsi/ucsi.h
@@ -496,7 +496,7 @@  ucsi_register_displayport(struct ucsi_connector *con,
 			  bool override, int offset,
 			  struct typec_altmode_desc *desc)
 {
-	return NULL;
+	return typec_port_register_altmode(con->port, desc);
 }
 
 static inline void