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 2548288b4fb0 ("USB: Fix: Don't skip endpoint descriptors with maxpacket=0")).

Fixes: 63978ab3e3e9 ("sound: add Edirol UA-101 support") Cc: stable@vger.kernel.org # 2.6.34 Signed-off-by: Johan Hovold johan@kernel.org --- sound/usb/misc/ua101.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/sound/usb/misc/ua101.c b/sound/usb/misc/ua101.c index 5834d1dc317e..4f6b20ed29dd 100644 --- a/sound/usb/misc/ua101.c +++ b/sound/usb/misc/ua101.c @@ -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; }