android/android_kernel_samsung_sm8650
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

BACKPORT: usb: typec: bus: verify partner exists in typec_altmode_attention

Browse Source 
Some usb hubs will negotiate DisplayPort Alt mode with the device
but will then negotiate a data role swap after entering the alt
mode. The data role swap causes the device to unregister all alt
modes, however the usb hub will still send Attention messages
even after failing to reregister the Alt Mode. type_altmode_attention
currently does not verify whether or not a device's altmode partner
exists, which results in a NULL pointer error when dereferencing
the typec_altmode and typec_altmode_ops belonging to the altmode
partner.

Verify the presence of a device's altmode partner before sending
the Attention message to the Alt Mode driver.

Fixes: 8a37d87d72 ("usb: typec: Bus type for alternate modes")
Cc: stable@vger.kernel.org
Signed-off-by: RD Babiera <rdbabiera@google.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20230814180559.923475-1-rdbabiera@google.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Bug: 288952921
(cherry picked from commit f23643306430f86e2f413ee2b986e0773e79da31)
[rd: changed return type of typec_altmode_attention to void to not break
 kmi, moved tcpm_log from error return to typec_altmode_attention as
 dev_warn]
Signed-off-by: RD Babiera <rdbabiera@google.com>
(cherry picked from https://android-review.googlesource.com/q/commit:e23c89c0b76305f9f264ba113d647710b956a540)
Merged-In: I054a6ef56b9b2d7c4e8167e8630a8c277910da88
Change-Id: I054a6ef56b9b2d7c4e8167e8630a8c277910da88
This commit is contained in:
RD Babiera 2023-09-05 22:07:07 +00:00 committed by Todd Kjos
parent 5cb3b26d79
commit f7e7874d9b
1 changed files with 14 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
drivers/usb/typec/bus.c
View File

@ -156,7 +156,20 @@ EXPORT_SYMBOL_GPL(typec_altmode_exit);
*/
void typec_altmode_attention(struct typec_altmode *adev, u32 vdo)
{
struct typec_altmode *pdev = &to_altmode(adev)->partner->adev;
struct altmode *partner = to_altmode(adev)->partner;
struct typec_altmode *pdev;
/*
* If partner is NULL then a NULL pointer error occurs when
* dereferencing pdev and its operations. The original upstream commit
* changes the return type so the tcpm can log when this occurs, but
* due to KMI restrictions we can only silently prevent the error for
* now.
*/
if (!partner)
return;
pdev = &partner->adev;
if (pdev->ops && pdev->ops->attention)
pdev->ops->attention(pdev, vdo);