The calculation of in_cables and out_cables bitmaps are done with the
bit shift by the value from the descriptor, which is an arbitrary
value, and can lead to UBSAN shift-out-of-bounds warnings.
Fix it by filtering the bad descriptor values with the check of the
upper bound 0x10 (the cable bitmaps are 16 bits).
Reported-by: syzbot+92e45ae45543f89e8c88@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
---
sound/usb/midi.c | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/sound/usb/midi.c b/sound/usb/midi.c
index c8213652470c..0c23fa6d8525 100644
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -1889,6 +1889,8 @@ static int snd_usbmidi_get_ms_info(struct snd_usb_midi *umidi,
ms_ep = find_usb_ms_endpoint_descriptor(hostep);
if (!ms_ep)
continue;
+ if (ms_ep->bNumEmbMIDIJack > 0x10)
+ continue;
if (usb_endpoint_dir_out(ep)) {
if (endpoints[epidx].out_ep) {
if (++epidx >= MIDI_MAX_ENDPOINTS) {
@@ -2141,6 +2143,8 @@ static int snd_usbmidi_detect_roland(struct snd_usb_midi *umidi,
cs_desc[1] == USB_DT_CS_INTERFACE &&
cs_desc[2] == 0xf1 &&
cs_desc[3] == 0x02) {
+ if (cs_desc[4] > 0x10 || cs_desc[5] > 0x10)
+ continue;
endpoint->in_cables = (1 << cs_desc[4]) - 1;
endpoint->out_cables = (1 << cs_desc[5]) - 1;
return snd_usbmidi_detect_endpoints(umidi, endpoint, 1);
--
2.26.2
