ALSA: ua101: fix division by zero at probe

Add the missing endpoint max-packet sanity check to probe() to avoid
division by zero in alloc_stream_buffers() in case a malicious device
has broken descriptors (or when doing descriptor fuzz testing).

Note that USB core will reject URBs submitted for endpoints with zero
wMaxPacketSize but that drivers doing packet-size calculations still
need to handle this (cf. commit 2548288b4f ("USB: Fix: Don't skip
endpoint descriptors with maxpacket=0")).

Fixes: 63978ab3e3 ("sound: add Edirol UA-101 support")
Cc: stable@vger.kernel.org      # 2.6.34
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20211026095401.26522-1-johan@kernel.org
Signed-off-by: Takashi Iwai <tiwai@suse.de>
This commit is contained in:
Johan Hovold 2021-10-26 11:54:01 +02:00 committed by Takashi Iwai
parent f4000b58b6
commit 55f261b73a
1 changed files with 2 additions and 2 deletions

View File

@ -1000,7 +1000,7 @@ static int detect_usb_format(struct ua101 *ua)
fmt_playback->bSubframeSize * ua->playback.channels;
epd = &ua->intf[INTF_CAPTURE]->altsetting[1].endpoint[0].desc;
if (!usb_endpoint_is_isoc_in(epd)) {
if (!usb_endpoint_is_isoc_in(epd) || usb_endpoint_maxp(epd) == 0) {
dev_err(&ua->dev->dev, "invalid capture endpoint\n");
return -ENXIO;
}
@ -1008,7 +1008,7 @@ static int detect_usb_format(struct ua101 *ua)
ua->capture.max_packet_bytes = usb_endpoint_maxp(epd);
epd = &ua->intf[INTF_PLAYBACK]->altsetting[1].endpoint[0].desc;
if (!usb_endpoint_is_isoc_out(epd)) {
if (!usb_endpoint_is_isoc_out(epd) || usb_endpoint_maxp(epd) == 0) {
dev_err(&ua->dev->dev, "invalid playback endpoint\n");
return -ENXIO;
}