From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3299C3FFAB6; Fri, 22 May 2026 14:20:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779459606; cv=none; b=j4Fj3/SQhmf8or6hnUGcc9KG7Qz3m+3rt21gXqdHItCVdGC3lbNTyjDll/M86NWLW8lIhng1AfwZU2yIrsg4vSnA7PIma3IS6iWxaDRKSxneV3yhz047NvwhqVcaNCsta5H91EeZMYicovNv4Ea2Gq3IAa3Tq/4BNA3QZShbieE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779459606; c=relaxed/simple; bh=11gouIwUW0jRrXK7IAlQZnvsti6SZR840f5szgMu3Ak=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=UM8mRBvwkWYtq77Dj33idRGVfzsnw+QiTWoW1hU2X3VPqfrC9BHXgWZH/Ng6/J4uJ5OCG5m44KfnqWrs36lM7V6Wl4NxC4OAlr8s+OpOwdKxJC/uTqhe6gka2OPSwsL3Ez3pN80ydiBEQSq0LF9SyqgswZ66NjgF8mJAN2EqtU0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Yy8NefCb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="Yy8NefCb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 686911F000E9; Fri, 22 May 2026 14:20:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1779459600; bh=L5ixqrYNlm/ZTh7tH9x0MeVLArrx0bUSChftgqmU4yU=; h=From:To:Cc:Subject:Date; b=Yy8NefCbNa8+tU2WTrkWByL7eCNMK3d/6HFIq6vvsP/6lhO7SuluF2GOLiPlcT+OM 5rKgSoa88GJjtnEm97J4EdWQV2NMIvc8t6FKk2KLQn1zRKgSDJM22zJAOjDIfzAWjr 64NM7F0khnaOgui/t2spFheg75t+57RtYn8WFfiGGsRkySo0rIjzu7SITbapm52TiS pIQ11BJpKqQ0VsNOkU4GXqlKTQYkG1rCBw7JR9aNaK81AJY73WWpXBCU2IoJEjvsRC 6f7gKzn7/R/296ocGcCvoE1rYmkgpXZhQ0vpAahhl+7x47HBxSiHyTQiXBtdEMASMc 6DG2p33cqhsUQ== Received: from johan by xi.lan with local (Exim 4.98.2) (envelope-from ) id 1wQQjF-00000003yTx-3xLf; Fri, 22 May 2026 16:19:57 +0200 From: Johan Hovold To: Johan Hovold Cc: Greg Kroah-Hartman , linux-usb@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Andrew Lunn Subject: [PATCH] USB: serial: mxuport: fix memory corruption with small endpoint Date: Fri, 22 May 2026 16:19:50 +0200 Message-ID: <20260522141950.947466-1-johan@kernel.org> X-Mailer: git-send-email 2.53.0 Precedence: bulk X-Mailing-List: linux-usb@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Make sure that the bulk-out endpoint max packet size is at least eight bytes to avoid user-controlled slab corruption should a malicious device report a smaller size. Fixes: ee467a1f2066 ("USB: serial: add Moxa UPORT 12XX/14XX/16XX driver") Cc: stable@vger.kernel.org # 3.14 Cc: Andrew Lunn Signed-off-by: Johan Hovold --- drivers/usb/serial/mxuport.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/usb/serial/mxuport.c b/drivers/usb/serial/mxuport.c index ad5fdf55a02e..c9b9928c473a 100644 --- a/drivers/usb/serial/mxuport.c +++ b/drivers/usb/serial/mxuport.c @@ -962,6 +962,14 @@ static int mxuport_calc_num_ports(struct usb_serial *serial, */ BUILD_BUG_ON(ARRAY_SIZE(epds->bulk_out) < 16); + /* + * The bulk-out buffers must be large enough for the four-byte header + * (and following data), but assume anything smaller than eight bytes + * is broken. + */ + if (usb_endpoint_maxp(epds->bulk_out[0]) < 8) + return -EINVAL; + for (i = 1; i < num_ports; ++i) epds->bulk_out[i] = epds->bulk_out[0]; -- 2.53.0