On Fri, Oct 20, 2023 at 01:21:32AM +0000, Jimmy Hu wrote:

It is possible that typec_register_partner() returns ERR_PTR on failure. When port->partner is an error, a NULL pointer dereference may occur as shown below.

[91222.095236][ T319] typec port0: failed to register partner (-17) ... [91225.061491][ T319] Unable to handle kernel NULL pointer dereference at virtual address 000000000000039f [91225.274642][ T319] pc : tcpm_pd_data_request+0x310/0x13fc [91225.274646][ T319] lr : tcpm_pd_data_request+0x298/0x13fc [91225.308067][ T319] Call trace: [91225.308070][ T319] tcpm_pd_data_request+0x310/0x13fc [91225.308073][ T319] tcpm_pd_rx_handler+0x100/0x9e8 [91225.355900][ T319] kthread_worker_fn+0x178/0x58c [91225.355902][ T319] kthread+0x150/0x200 [91225.355905][ T319] ret_from_fork+0x10/0x30

Add a check for port->partner to avoid dereferencing a NULL pointer.

Fixes: 5e1d4c49fbc8 ("usb: typec: tcpm: Determine common SVDM Version") Cc: stable@vger.kernel.org Signed-off-by: Jimmy Hu hhhuuu@google.com

Acked-by: Heikki Krogerus heikki.krogerus@linux.intel.com

---

drivers/usb/typec/tcpm/tcpm.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/usb/typec/tcpm/tcpm.c b/drivers/usb/typec/tcpm/tcpm.c index 6e843c511b85..792ec4ac7d8d 100644 --- a/drivers/usb/typec/tcpm/tcpm.c +++ b/drivers/usb/typec/tcpm/tcpm.c @@ -1625,6 +1625,9 @@ static int tcpm_pd_svdm(struct tcpm_port *port, struct typec_altmode *adev, if (PD_VDO_VID(p[0]) != USB_SID_PD) break;

• 	if (IS_ERR_OR_NULL(port->partner))
  

• 		break;
  

• if (PD_VDO_SVDM_VER(p[0]) < svdm_version) {
  	typec_partner_set_svdm_version(port->partner,
  				       PD_VDO_SVDM_VER(p[0]));