[PATCH 6.6 010/175] HID: asus: avoid memory leak in asus_report_fixup()

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.6-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Günther Noack <gnoack@google.com>

[ Upstream commit 2bad24c17742fc88973d6aea526ce1353f5334a3 ]

The asus_report_fixup() function was returning a newly allocated
kmemdup()-allocated buffer, but never freeing it.  Switch to
devm_kzalloc() to ensure the memory is managed and freed automatically
when the device is removed.

The caller of report_fixup() does not take ownership of the returned
pointer, but it is permitted to return a pointer whose lifetime is at
least that of the input buffer.

Also fix a harmless out-of-bounds read by copying only the original
descriptor size.

Assisted-by: Gemini-CLI:Google Gemini 3
Signed-off-by: Günther Noack <gnoack@google.com>
Signed-off-by: Benjamin Tissoires <bentiss@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hid/hid-asus.c | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/hid/hid-asus.c b/drivers/hid/hid-asus.c
index d971e339b5eac..529b23b67ec4b 100644
--- a/drivers/hid/hid-asus.c
+++ b/drivers/hid/hid-asus.c
@@ -1200,14 +1200,21 @@ static __u8 *asus_report_fixup(struct hid_device *hdev, __u8 *rdesc,
 		 */
 		if (*rsize == rsize_orig &&
 			rdesc[offs] == 0x09 && rdesc[offs + 1] == 0x76) {
-			*rsize = rsize_orig + 1;
-			rdesc = kmemdup(rdesc, *rsize, GFP_KERNEL);
-			if (!rdesc)
-				return NULL;
+			__u8 *new_rdesc;
+
+			new_rdesc = devm_kzalloc(&hdev->dev, rsize_orig + 1,
+						 GFP_KERNEL);
+			if (!new_rdesc)
+				return rdesc;
 
 			hid_info(hdev, "Fixing up %s keyb report descriptor\n",
 				drvdata->quirks & QUIRK_T100CHI ?
 				"T100CHI" : "T90CHI");
+
+			memcpy(new_rdesc, rdesc, rsize_orig);
+			*rsize = rsize_orig + 1;
+			rdesc = new_rdesc;
+
 			memmove(rdesc + offs + 4, rdesc + offs + 2, 12);
 			rdesc[offs] = 0x19;
 			rdesc[offs + 1] = 0x00;
-- 
2.51.0