Patch "usb: dwc3: ep0: Fix mem corruption on OUT transfers of more than 512 bytes" has been added to the 4.1-stable tree

This is a note to let you know that I've just added the patch titled

usb: dwc3: ep0: Fix mem corruption on OUT transfers of more than 512 bytes

to the 4.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
usb-dwc3-ep0-fix-mem-corruption-on-out-transfers-of-more-than-512-bytes.patch
and it can be found in the queue-4.1 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Kishon Vijay Abraham I <[email protected]>
Date: Mon, 27 Jul 2015 12:25:27 +0530
Subject: usb: dwc3: ep0: Fix mem corruption on OUT transfers of more than 512 bytes

From: Kishon Vijay Abraham I <[email protected]>

commit b2fb5b1a0f50d3ebc12342c8d8dead245e9c9d4e upstream.

DWC3 uses bounce buffer to handle non max packet aligned OUT transfers and the size of bounce buffer is 512 bytes. However if the host initiates OUT transfers of size more than 512 bytes (and non max packet aligned), the driver throws a WARN dump but still programs the TRB to receive more than 512 bytes. This will cause bounce buffer to overflow and corrupt the adjacent memory locations which can be fatal.

Fix it by programming the TRB to receive a maximum of DWC3_EP0_BOUNCE_SIZE
(512) bytes.

---
 drivers/usb/dwc3/ep0.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

@@ -820,6 +820,11 @@ static void dwc3_ep0_complete_data(struc
 		unsigned maxp = ep0->endpoint.maxpacket;
 
 		transfer_size += (maxp - (transfer_size % maxp));
+
+		/* Maximum of DWC3_EP0_BOUNCE_SIZE can only be received */
+		if (transfer_size > DWC3_EP0_BOUNCE_SIZE)
+			transfer_size = DWC3_EP0_BOUNCE_SIZE;
+
 		transferred = min_t(u32, ur->length,
 				transfer_size - length);
 		memcpy(ur->buf, dwc->ep0_bounce, transferred);

@@ -941,11 +946,14 @@ static void __dwc3_ep0_do_control_data(s
 			return;
 		}
 
-		WARN_ON(req->request.length > DWC3_EP0_BOUNCE_SIZE);
-
 		maxpacket = dep->endpoint.maxpacket;
 		transfer_size = roundup(req->request.length, maxpacket);
 
+		if (transfer_size > DWC3_EP0_BOUNCE_SIZE) {
+			dev_WARN(dwc->dev, "bounce buf can't handle req len\n");
+			transfer_size = DWC3_EP0_BOUNCE_SIZE;
+		}
+
 		dwc->ep0_bounced = true;
 
 		/*

Patches currently in stable-queue which might be from [email protected] are

queue-4.1/usb-dwc3-ep0-fix-mem-corruption-on-out-transfers-of-more-than-512-bytes.patch