FAILED: patch "[PATCH] HID: prodikeys: validate fixed-format MIDI reports" failed to apply to 6.1-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.1-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 <stable@vger.kernel.org>.

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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 0ff37294c41bd925258893310398bc2b45fcd4a7
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026110446-amnesty-outsmart-92b6@gregkh' --subject-prefix 'PATCH 6.1.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From 0ff37294c41bd925258893310398bc2b45fcd4a7 Mon Sep 17 00:00:00 2001
From: Jiale Yao <yaojiale02@163.com>
Date: Thu, 24 Sep 2026 22:44:11 +0800
Subject: [PATCH] HID: prodikeys: validate fixed-format MIDI reports

The HID core invokes raw_event callbacks before validating the report
length.  Prodikeys reports 0x01 and 0x04 are passed to handlers that always
read bytes one through three, regardless of the supplied size.  A truncated
report can therefore cause an out-of-bounds read.

Require four bytes for the two fixed-format reports.  Keep report 0x03 on
its existing variable-length path, which derives the number of note pairs
from size and only accesses complete pairs.

Commit 47669bec44fe ("HID: asus: refactor the two workqueues and init
sequence") added the same kind of raw_event length validation to hid-asus.

Fixes: 3a370ca1dcf8 ("HID: Prodikeys PC-MIDI HID Driver")
Cc: stable@vger.kernel.org
Signed-off-by: Jiale Yao <yaojiale02@163.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>

diff --git a/drivers/hid/hid-prodikeys.c b/drivers/hid/hid-prodikeys.c
index fba01e4fcab1..bf5add40d3e1 100644
--- a/drivers/hid/hid-prodikeys.c
+++ b/drivers/hid/hid-prodikeys.c
@@ -772,8 +772,13 @@ static int pk_raw_event(struct hid_device *hdev, struct hid_report *report,
 		if (report->id == data[0])
 			switch (report->id) {
 			case 0x01: /* midi keys (qwerty)*/
-			case 0x03: /* midi keyboard (musical)*/
 			case 0x04: /* extra/midi keys (qwerty)*/
+				if (size < 4)
+					break;
+				ret = pcmidi_handle_report(pm, report->id,
+							   data, size);
+				break;
+			case 0x03: /* midi keyboard (musical)*/
 				ret = pcmidi_handle_report(pm,
 						report->id, data, size);
 				break;