diff mbox series

[3/5] usb: dwc3: gadget: Fix looping of queued SG entries

Message ID d07a7c4aa0fcf746cdca0515150dbe5c52000af7.1731545781.git.Thinh.Nguyen@synopsys.com (mailing list archive)
State Accepted
Commit b7fc65f5141c24785dc8c19249ca4efcf71b3524
Headers show
Series usb: dwc3: gadget: Misc fixes and cleanup | expand

Commit Message

Thinh Nguyen Nov. 14, 2024, 1:02 a.m. UTC 
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: c96e6725db9d ("usb: dwc3: gadget: Correct the logic for queuing sgs")
Signed-off-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
---
 drivers/usb/dwc3/gadget.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)
diff mbox series

Patch

diff --git a/drivers/usb/dwc3/gadget.c b/drivers/usb/dwc3/gadget.c
index 38c3769a6c48..3a5a0d8be33c 100644
--- a/drivers/usb/dwc3/gadget.c
+++ b/drivers/usb/dwc3/gadget.c
@@ -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) {