===================================================================
@@ -348,6 +348,11 @@ static int usb_parse_endpoint(struct dev
/* Validate the wMaxPacketSize field */
maxp = usb_endpoint_maxp(&endpoint->desc);
+ if (maxp == 0) {
+ dev_warn(ddev, "config %d interface %d altsetting %d endpoint 0x%X has wMaxPacketSize 0, skipping\n",
+ cfgno, inum, asnum, d->bEndpointAddress);
+ goto skip_to_next_endpoint_or_interface_descriptor;
+ }
/* Find the highest legal maxpacket size for this endpoint */
i = 0; /* additional transactions per microframe */
Endpoints with a maxpacket length of 0 are probably useless. They can't transfer any data, and it's not at all unlikely that an HCD will crash or hang when trying to handle an URB for such an endpoint. Currently the USB core does not check for endpoints having a maxpacket value of 0. This patch adds a check, printing a warning and skipping over any endpoints it catches. Now, the USB spec does not rule out endpoints having maxpacket = 0. But since they wouldn't have any practical use, there doesn't seem to be any good reason for us to accept them. Signed-off-by: Alan Stern <stern@rowland.harvard.edu> --- [as1924] drivers/usb/core/config.c | 5 +++++ 1 file changed, 5 insertions(+)