From b2fb5b1a0f50d3ebc12342c8d8dead245e9c9d4e Mon Sep 17 00:00:00 2001 From: Kishon Vijay Abraham I Date: Mon, 27 Jul 2015 12:25:27 +0530 Subject: [PATCH] usb: dwc3: ep0: Fix mem corruption on OUT transfers of more than 512 bytes 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. Cc: # 3.4+ Signed-off-by: Kishon Vijay Abraham I Signed-off-by: Felipe Balbi --- drivers/usb/dwc3/ep0.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/drivers/usb/dwc3/ep0.c b/drivers/usb/dwc3/ep0.c index 69e769c..06ecd1e 100644 --- a/drivers/usb/dwc3/ep0.c +++ b/drivers/usb/dwc3/ep0.c @@ -820,6 +820,11 @@ static void dwc3_ep0_complete_data(struct dwc3 *dwc, 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(struct dwc3 *dwc, 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; /* -- 2.7.4