The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5d187c0454ef4c5e046a81af36882d4d515922ec Mon Sep 17 00:00:00 2001

From: Thinh Nguyen Thinh.Nguyen@synopsys.com Date: Thu, 6 Aug 2020 19:46:23 -0700 Subject: [PATCH] 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: a31e63b608ff ("usb: dwc3: gadget: Correct handling of scattergather lists") Signed-off-by: Thinh Nguyen thinhn@synopsys.com Signed-off-by: Felipe Balbi balbi@kernel.org

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c index e44bfc3b5096..f9231253cbed 100644 --- a/drivers/usb/dwc3/gadget.c +++ b/drivers/usb/dwc3/gadget.c @@ -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); } }