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 5649D3F7ABC; Wed, 20 May 2026 18:27:11 +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=1779301632; cv=none; b=pqfEwbZMT7uyWSs/XnO/PmY6umJrCloPKUdqaKqZ1KtwgqqBvn7CEmgkYTuPNNJeD/WCbxy9IBC2zLANnILQ+w40KLnt0j23QW+Px4UfSFd5f0h0hii+NWzMY13uEg0jAY2WI6x8hiW/gJnUcQJeWagW3BBUC7b8kE6vWeJtclw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779301632; c=relaxed/simple; bh=I8QdBjtAoepKWs9hjaKPH2xkojK1/7Wi6vQqfHvEd2Y=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=JY1uOiXScKxnp04BqA2RWcvOhYv3GCt8R3ILSnEIfMVndPJU0AHQSCLIRQtjt4BzsAVsencMwuGM70vwiLSZKot+H962F+v8Rd3eiELjHrJjpO82FAVbg95WUk60fBaNAaox22c+u+JGRDiIU70//fjcdm3Bea8JJMNVgPuXQsU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=CgccpnNl; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="CgccpnNl" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 95B781F000E9; Wed, 20 May 2026 18:27:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1779301631; bh=gH/pTljXszOptj+XNdpAZe7VYU3SIdDO0A+Ldk9GgeM=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=CgccpnNlgiBRpAJqcfveyYoS6zKqhSugC+De+PkmubWbuGGg9mDrl0kaina7+pkVR RQORysjeWNli2K5EUdrHj26jHgKHpszCV27WCP3MzTkBVGdSKvk5qB0YEo4eKlCo55 /T6ZwNlKhs9WhZKQDdVXUpjTsNsn5C64+CwbM2Ik= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, =?UTF-8?q?C=C3=A1ssio=20Gabriel?= , Takashi Iwai Subject: [PATCH 6.12 628/666] ALSA: usb-audio: Bound MIDI 2.0 endpoint descriptor scans Date: Wed, 20 May 2026 18:23:59 +0200 Message-ID: <20260520162124.888420255@linuxfoundation.org> X-Mailer: git-send-email 2.54.0 In-Reply-To: <20260520162111.222830634@linuxfoundation.org> References: <20260520162111.222830634@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Cássio Gabriel commit 918be519c7876329e1b6e2ea1c59f0b75e792dca upstream. The USB MIDI 2.0 endpoint parser has the same descriptor walking pattern as the legacy MIDI parser. It validates bLength against bNumGrpTrmBlock before reading baAssoGrpTrmBlkID[], but not against the remaining bytes in the endpoint-extra scan. A malformed device can therefore make later baAssoGrpTrmBlkID[] reads consume bytes past the walked descriptor. Reject zero-length and overlong descriptors while walking endpoint extras. Fixes: ff49d1df79ae ("ALSA: usb-audio: USB MIDI 2.0 UMP support") Cc: stable@vger.kernel.org Signed-off-by: Cássio Gabriel Link: https://patch.msgid.link/20260507-usb-midi-endpoint-scan-bounds-v1-2-329d7348160e@gmail.com Signed-off-by: Takashi Iwai Signed-off-by: Greg Kroah-Hartman --- sound/usb/midi2.c | 12 +++++++----- 1 file changed, 7 insertions(+), 5 deletions(-) --- a/sound/usb/midi2.c +++ b/sound/usb/midi2.c @@ -504,15 +504,17 @@ static void *find_usb_ms_endpoint_descri while (extralen > 3) { struct usb_ms_endpoint_descriptor *ms_ep = (struct usb_ms_endpoint_descriptor *)extra; + int length = ms_ep->bLength; - if (ms_ep->bLength > 3 && + if (!length || length > extralen) + break; + + if (length > 3 && ms_ep->bDescriptorType == USB_DT_CS_ENDPOINT && ms_ep->bDescriptorSubtype == subtype) return ms_ep; - if (!extra[0]) - break; - extralen -= extra[0]; - extra += extra[0]; + extralen -= length; + extra += length; } return NULL; }