On Tue, Jul 23, 2024 at 10:13:44PM GMT, Ma Ke wrote:

When dp->con->partner is an error, a NULL pointer dereference may occur. Add a check for dp->con->partner to avoid dereferencing a NULL pointer.

Cc: stable@vger.kernel.org Fixes: 372adf075a43 ("usb: typec: ucsi: Determine common SVDM Version") Signed-off-by: Ma Ke make24@iscas.ac.cn

---

Changes in v2:

• added Cc stable line;
• fixed a typo.

---

drivers/usb/typec/ucsi/displayport.c | 2 ++ 1 file changed, 2 insertions(+)

diff --git a/drivers/usb/typec/ucsi/displayport.c b/drivers/usb/typec/ucsi/displayport.c index 420af5139c70..ecc706e0800d 100644 --- a/drivers/usb/typec/ucsi/displayport.c +++ b/drivers/usb/typec/ucsi/displayport.c @@ -222,6 +222,8 @@ static int ucsi_displayport_vdm(struct typec_altmode *alt, switch (cmd_type) { case CMDT_INIT: if (PD_VDO_SVDM_VER(header) < svdm_version) {

• 	if (IS_ERR_OR_NULL(dp->con->partner))
  

Usually IS_ERR_OR_NULL is one of the red flags. It is either IS_ERR or NULL, but not both.

Also could you please describe the path how we can end up here without a proper dp->con->partner.

• 		break;
  typec_partner_set_svdm_version(dp->con->partner, PD_VDO_SVDM_VER(header));
  svdm_version = PD_VDO_SVDM_VER(header);
  

  }

-- 2.25.1