On Tue, Jun 11, 2019 at 10:19:27PM +1000, Vladimir Yerilov wrote:
> Hi Heikki,
>
> > What do you have connected to the USB Type-C connectors on the
> machine when that happens?
>
> Now, on 5.2-rc4, it happens only during boot and when power cord is
> connected to laptop's type-c charging port. Another port, which does
> not support charging, does not cause this problem, I mean I can have
> something connected to it or not, no issue is observed if charger is
> disconnected. I even tried to connect my hub to the guilty charging
> port, everything works fine until hub is powered from the charger, in
> that case the bug happens again. This differs from my previous tests
> when whatever I had connected to the charging port, caused failures,
> even type C to A OTG cable. To summarize: now it happens when power
> cord from the charger is connected during the boot, but if I connect
> it after boot (e.g. after logging in to my X session), no crash
> occurs.
>
> > Can you use the machine normally when nothing is connected to the USB Type-C connectors
>
> Yeah, everything is great when nothing is connected to the faulty
> charging port during the boot, and charger may be connected later, but
> it's kinda... wrong.
>
> > Is it possible to send complete dmesg output after that happened?
>
> You can find everything attached (done with journalctl -k -xb)
Thanks. I don't see anything the driver is doing wrong. I'm attaching
a patch. Can you test if it fixes the issue?
Br,
--
heikki
>From d6979950ee911194dab9ae7513fe36dc3730f7a9 Mon Sep 17 00:00:00 2001
From: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
Date: Tue, 11 Jun 2019 11:10:25 +0300
Subject: [PATCH] usb: typec: Make sure an alt mode exist before getting its
partner
Interim. For testing only!
Adding check to typec_altmode_get_partner() to prevent
potential NULL pointer dereference.
Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx>
---
drivers/usb/typec/bus.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/usb/typec/bus.c b/drivers/usb/typec/bus.c
index 76299b6ff06d..74cb3c2ecb34 100644
--- a/drivers/usb/typec/bus.c
+++ b/drivers/usb/typec/bus.c
@@ -192,7 +192,7 @@ EXPORT_SYMBOL_GPL(typec_altmode_vdm);
const struct typec_altmode *
typec_altmode_get_partner(struct typec_altmode *adev)
{
- return &to_altmode(adev)->partner->adev;
+ return adev ? &to_altmode(adev)->partner->adev : NULL;
}
EXPORT_SYMBOL_GPL(typec_altmode_get_partner);
--
2.20.1
