Commit 5d187c04 authored by Thinh Nguyen's avatar Thinh Nguyen Committed by Felipe Balbi
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usb: dwc3: gadget: Don't setup more than requested 



The SG list may be set up with entry size more than the requested
length. Check the usb_request->length and make sure that we don't setup
the TRBs to send/receive more than requested. This case may occur when
the SG entry is allocated up to a certain minimum size, but the request
length is less than that. It can also occur when the request is reused
for a different request length.

Cc: <stable@vger.kernel.org> # v4.18+
Fixes: a31e63b6 ("usb: dwc3: gadget: Correct handling of scattergather lists")
Signed-off-by: default avatarThinh Nguyen <thinhn@synopsys.com>
Signed-off-by: default avatarFelipe Balbi <balbi@kernel.org>
parent 07c84341

drivers/usb/dwc3/gadget.c

+35 −16
Original line number Diff line number Diff line
@@ -1054,27 +1054,25 @@ static void __dwc3_prepare_one_trb(struct dwc3_ep *dep, struct dwc3_trb *trb, 
 * dwc3_prepare_one_trb - setup one TRB from one request

 * @dep: endpoint for which this request is prepared

 * @req: dwc3_request pointer

 * @trb_length: buffer size of the TRB

 * @chain: should this TRB be chained to the next?

 * @node: only for isochronous endpoints. First TRB needs different type.

 */

static void dwc3_prepare_one_trb(struct dwc3_ep *dep,

		struct dwc3_request *req, unsigned chain, unsigned node)

		struct dwc3_request *req, unsigned int trb_length,

		unsigned chain, unsigned node)

{

	struct dwc3_trb		*trb;

	unsigned int		length;

	dma_addr_t		dma;

	unsigned		stream_id = req->request.stream_id;

	unsigned		short_not_ok = req->request.short_not_ok;

	unsigned		no_interrupt = req->request.no_interrupt;

	unsigned		is_last = req->request.is_last;



	if (req->request.num_sgs > 0) {

		length = sg_dma_len(req->start_sg);

	if (req->request.num_sgs > 0)

		dma = sg_dma_address(req->start_sg);

	} else {

		length = req->request.length;

	else

		dma = req->request.dma;

	}



	trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1086,7 +1084,7 @@ static void dwc3_prepare_one_trb(struct dwc3_ep *dep, 


	req->num_trbs++;



	__dwc3_prepare_one_trb(dep, trb, dma, length, chain, node,

	__dwc3_prepare_one_trb(dep, trb, dma, trb_length, chain, node,

			stream_id, short_not_ok, no_interrupt, is_last);

}
@@ -1096,16 +1094,27 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 
	struct scatterlist *sg = req->start_sg;

	struct scatterlist *s;

	int		i;



	unsigned int length = req->request.length;

	unsigned int remaining = req->request.num_mapped_sgs

		- req->num_queued_sgs;



	/*

	 * 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)

		length -= sg_dma_len(s);



	for_each_sg(sg, s, remaining, i) {

		unsigned int length = req->request.length;

		unsigned int maxp = usb_endpoint_maxp(dep->endpoint.desc);

		unsigned int rem = length % maxp;

		unsigned int trb_length;

		unsigned chain = true;



		trb_length = min_t(unsigned int, length, sg_dma_len(s));



		length -= trb_length;



		/*

		 * IOMMU driver is coalescing the list of sgs which shares a

		 * page boundary into one and giving it to USB driver. With
@@ -1113,7 +1122,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 
		 * sgs passed. So mark the chain bit to false if it isthe last

		 * mapped sg.

		 */

		if (i == remaining - 1)

		if ((i == remaining - 1) || !length)

			chain = false;



		if (rem && usb_endpoint_dir_out(dep->endpoint.desc) && !chain) {
@@ -1123,7 +1132,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 
			req->needs_extra_trb = true;



			/* prepare normal TRB */

			dwc3_prepare_one_trb(dep, req, true, i);

			dwc3_prepare_one_trb(dep, req, trb_length, true, i);



			/* Now prepare one extra TRB to align transfer size */

			trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1135,7 +1144,7 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 
					req->request.no_interrupt,

					req->request.is_last);

		} else {

			dwc3_prepare_one_trb(dep, req, chain, i);

			dwc3_prepare_one_trb(dep, req, trb_length, chain, i);

		}



		/*
@@ -1150,6 +1159,16 @@ static void dwc3_prepare_one_trb_sg(struct dwc3_ep *dep, 


		req->num_queued_sgs++;



		/*

		 * The number of pending SG entries may not correspond to the

		 * number of mapped SG entries. If all the data are queued, then

		 * don't include unused SG entries.

		 */

		if (length == 0) {

			req->num_pending_sgs -= req->request.num_mapped_sgs - req->num_queued_sgs;

			break;

		}



		if (!dwc3_calc_trbs_left(dep))

			break;

	}
@@ -1169,7 +1188,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, 
		req->needs_extra_trb = true;



		/* prepare normal TRB */

		dwc3_prepare_one_trb(dep, req, true, 0);

		dwc3_prepare_one_trb(dep, req, length, true, 0);



		/* Now prepare one extra TRB to align transfer size */

		trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1187,7 +1206,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, 
		req->needs_extra_trb = true;



		/* prepare normal TRB */

		dwc3_prepare_one_trb(dep, req, true, 0);

		dwc3_prepare_one_trb(dep, req, length, true, 0);



		/* Now prepare one extra TRB to handle ZLP */

		trb = &dep->trb_pool[dep->trb_enqueue];
@@ -1198,7 +1217,7 @@ static void dwc3_prepare_one_trb_linear(struct dwc3_ep *dep, 
				req->request.no_interrupt,

				req->request.is_last);

	} else {

		dwc3_prepare_one_trb(dep, req, false, 0);

		dwc3_prepare_one_trb(dep, req, length, false, 0);

	}

}

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