Commit d2d8c17a authored by Nathan Rebello's avatar Nathan Rebello Committed by Greg Kroah-Hartman
Browse files

usb: typec: ucsi: validate connector number in ucsi_notify_common() 



The connector number extracted from CCI via UCSI_CCI_CONNECTOR() is a
7-bit field (0-127) that is used to index into the connector array in
ucsi_connector_change(). However, the array is only allocated for the
number of connectors reported by the device (typically 2-4 entries).

A malicious or malfunctioning device could report an out-of-range
connector number in the CCI, causing an out-of-bounds array access in
ucsi_connector_change().

Add a bounds check in ucsi_notify_common(), the central point where CCI
is parsed after arriving from hardware, so that bogus connector numbers
are rejected before they propagate further.

Fixes: bdc62f2b ("usb: typec: ucsi: Simplified registration and I/O API")
Cc: stable <stable@kernel.org>
Reviewed-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: default avatarNathan Rebello <nathan.c.rebello@gmail.com>
Link: https://patch.msgid.link/20260313222453.123-1-nathan.c.rebello@gmail.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 8a768552

drivers/usb/typec/ucsi/ucsi.c

+7 −2
Original line number Diff line number Diff line
@@ -43,8 +43,13 @@ void ucsi_notify_common(struct ucsi *ucsi, u32 cci) 
	if (cci & UCSI_CCI_BUSY)

		return;



	if (UCSI_CCI_CONNECTOR(cci))

	if (UCSI_CCI_CONNECTOR(cci)) {

		if (UCSI_CCI_CONNECTOR(cci) <= ucsi->cap.num_connectors)

			ucsi_connector_change(ucsi, UCSI_CCI_CONNECTOR(cci));

		else

			dev_err(ucsi->dev, "bogus connector number in CCI: %lu\n",

				UCSI_CCI_CONNECTOR(cci));

	}



	if (cci & UCSI_CCI_ACK_COMPLETE &&

	    test_and_clear_bit(ACK_PENDING, &ucsi->flags))