From: Chris Wulff Date: Thu, 25 Jul 2024 01:04:20 +0000 (-0400) Subject: usb: gadget: core: Check for unset descriptor X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=973a57891608a98e894db2887f278777f564de18;p=linux.git usb: gadget: core: Check for unset descriptor Make sure the descriptor has been set before looking at maxpacket. This fixes a null pointer panic in this case. This may happen if the gadget doesn't properly set up the endpoint for the current speed, or the gadget descriptors are malformed and the descriptor for the speed/endpoint are not found. No current gadget driver is known to have this problem, but this may cause a hard-to-find bug during development of new gadgets. Fixes: 54f83b8c8ea9 ("USB: gadget: Reject endpoints with 0 maxpacket value") Cc: stable@vger.kernel.org Signed-off-by: Chris Wulff Link: https://lore.kernel.org/r/20240725010419.314430-2-crwulff@gmail.com Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/usb/gadget/udc/core.c b/drivers/usb/gadget/udc/core.c index b0a613758414..cf6478f97f4a 100644 --- a/drivers/usb/gadget/udc/core.c +++ b/drivers/usb/gadget/udc/core.c @@ -118,12 +118,10 @@ int usb_ep_enable(struct usb_ep *ep) goto out; /* UDC drivers can't handle endpoints with maxpacket size 0 */ - if (usb_endpoint_maxp(ep->desc) == 0) { - /* - * We should log an error message here, but we can't call - * dev_err() because there's no way to find the gadget - * given only ep. - */ + if (!ep->desc || usb_endpoint_maxp(ep->desc) == 0) { + WARN_ONCE(1, "%s: ep%d (%s) has %s\n", __func__, ep->address, ep->name, + (!ep->desc) ? "NULL descriptor" : "maxpacket 0"); + ret = -EINVAL; goto out; }