FAILED: patch "[PATCH] usb: typec: ucsi: validate connector number in" failed to apply to 6.6-stable tree

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x d2d8c17ac01a1b1f638ea5d340a884ccc5015186
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<[email protected]>' --in-reply-to '2026040841-wheat-refund-0488@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From d2d8c17ac01a1b1f638ea5d340a884ccc5015186 Mon Sep 17 00:00:00 2001
From: Nathan Rebello <[email protected]>
Date: Fri, 13 Mar 2026 18:24:53 -0400
Subject: [PATCH] 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.

index f38a4d7ebc42..8333bdaf5566 100644
@@ -43,8 +43,13 @@ void ucsi_notify_common(struct ucsi *ucsi, u32 cci)
 	if (cci & UCSI_CCI_BUSY)
 		return;
 
-	if (UCSI_CCI_CONNECTOR(cci))
-		ucsi_connector_change(ucsi, 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))