usb: typec: ucsi: displayport: NAK DP_CMD_CONFIGURE without a payload VDO

ucsi_displayport_vdm() handles a DP_CMD_CONFIGURE by copying the first
payload VDO from data[], but unlike the equivalent handler in
altmodes/displayport.c it does not check that count covers a VDO beyond
the header.  A header-only Configure VDM (count == 1) would read one u32
past the caller's array.

In the normal UCSI path the caller controls count, so this is hardening
for non-standard delivery paths.  NAK and bail when no configuration VDO
is present, matching the generic DP altmode driver's existing guard.

Assisted-by: gkh_clanker_t1000
Cc: Pooja Katiyar <pooja.katiyar@intel.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: stable <stable@kernel.org>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://patch.msgid.link/2026051351-vividly-flattered-eb3d@gregkh
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Greg Kroah-Hartman 2026-05-13 17:52:54 +02:00
parent 3389c149c6
commit 167dd8d122

View File

@ -240,6 +240,10 @@ static int ucsi_displayport_vdm(struct typec_altmode *alt,
dp->header |= VDO_CMDT(CMDT_RSP_ACK);
break;
case DP_CMD_CONFIGURE:
if (count < 2) {
dp->header |= VDO_CMDT(CMDT_RSP_NAK);
break;
}
dp->data.conf = *data;
if (ucsi_displayport_configure(dp)) {
dp->header |= VDO_CMDT(CMDT_RSP_NAK);