Commit b7fc65f5 authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Greg Kroah-Hartman
Browse files

usb: dwc3: gadget: Fix looping of queued SG entries 



The dwc3_request->num_queued_sgs is decremented on completion. If a
partially completed request is handled, then the
dwc3_request->num_queued_sgs no longer reflects the total number of
num_queued_sgs (it would be cleared).

Correctly check the number of request SG entries remained to be prepare
and queued. Failure to do this may cause null pointer dereference when
accessing non-existent SG entry.

Cc: stable@vger.kernel.org
Fixes: c96e6725 ("usb: dwc3: gadget: Correct the logic for queuing sgs")
Signed-off-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Link: https://lore.kernel.org/r/d07a7c4aa0fcf746cdca0515150dbe5c52000af7.1731545781.git.Thinh.Nguyen@synopsys.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 02a6982b

drivers/usb/dwc3/gadget.c

+3 −3
Original line number Diff line number Diff line
@@ -1470,8 +1470,8 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
	struct scatterlist *s;

	int		i;

	unsigned int length = req->request.length;

	unsigned int remaining = req->request.num_mapped_sgs

		- req->num_queued_sgs;

	unsigned int remaining = req->num_pending_sgs;

	unsigned int num_queued_sgs = req->request.num_mapped_sgs - remaining;

	unsigned int num_trbs = req->num_trbs;

	bool needs_extra_trb = dwc3_needs_extra_trb(dep, req);
@@ -1479,7 +1479,7 @@ static int dwc3_prepare_trbs_sg(struct dwc3_ep *dep, 
	 * If we resume preparing the request, then get the remaining length of

	 * the request and resume where we left off.

	 */

	for_each_sg(req->request.sg, s, req->num_queued_sgs, i)

	for_each_sg(req->request.sg, s, num_queued_sgs, i)

		length -= sg_dma_len(s);



	for_each_sg(sg, s, remaining, i) {