The driver must make sure there is an actual connection before checking details about the USB Power Delivery contract. Those details are not valid unless there is a connection. This fixes NULL pointer dereference that is caused by an attempt to register bogus partner alternate mode that the firmware on some platform may report before the actual connection. Reported-by: Chris Hixon <linux-kernel-bugs@xxxxxxxxxxxxx> Fixes: 6cbe4b2d5a3f ("usb: typec: ucsi: Check the partner alt modes always if there is PD contract") Link: https://bugzilla.kernel.org/show_bug.cgi?id=215117 Signed-off-by: Heikki Krogerus <heikki.krogerus@xxxxxxxxxxxxxxx> --- Hi, Instead of using the "BugLink" tag, I'm now using "Link" tag with the link to the bug as requested. There was a request to have also another Link tag pointing to some other discussion on the mailing list, but I failed to understand what was the point with that - I also didn't find any commits where something like that had been used before. I may be mistaken here, but I got the impression that you create the mailing list discussion just so you can have the extra Link tag pointing to it, and that Link tag you want only because you have made your scripts rely on it. The extra email thread in any case does not seem to contain any real additional information that the bug report does not have, so the extra Link tag pointing to it does not provide any real value on top of the link to bug itself. thanks, -- drivers/usb/typec/ucsi/ucsi.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/usb/typec/ucsi/ucsi.c b/drivers/usb/typec/ucsi/ucsi.c index 9d6b7e02d6efb..f0c2fa19f3e0f 100644 --- a/drivers/usb/typec/ucsi/ucsi.c +++ b/drivers/usb/typec/ucsi/ucsi.c @@ -1164,7 +1164,9 @@ static int ucsi_register_port(struct ucsi *ucsi, int index) ret = 0; } - if (UCSI_CONSTAT_PWR_OPMODE(con->status.flags) == UCSI_CONSTAT_PWR_OPMODE_PD) { + if (con->partner && + UCSI_CONSTAT_PWR_OPMODE(con->status.flags) == + UCSI_CONSTAT_PWR_OPMODE_PD) { ucsi_get_src_pdos(con); ucsi_check_altmodes(con); } -- 2.34.1