Hi On Tue, Jun 9, 2015 at 3:44 PM, Kishon Vijay Abraham I <kishon@xxxxxx> wrote: > Hi, > > On Tuesday 09 June 2015 08:09 PM, Michael Trimarchi wrote: >> >> Hi >> >> On Jun 9, 2015 4:36 PM, "Kishon Vijay Abraham I" <kishon@xxxxxx >> <mailto:kishon@xxxxxx>> wrote: >> > >> > 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. >> > >> > Signed-off-by: Kishon Vijay Abraham I <kishon@xxxxxx >> <mailto:kishon@xxxxxx>> >> >> > --- >> > Steps to see the issue (before this patch) >> > 1) Insert g_zero in DUT >> > 2) run './testusb -t 14 -c 1 -s 520 -v 1' in host (size should be > >> 512) >> > >> > The test should FAIL since bounce buffer can handle only 512 bytes, but >> the >> > test PASS. There is a WARN dump in DUT but still there will be memory >> > corruption since the bounce buffer overflows. >> > >> > Tested this patch using USB3 Gen X CV (ch9 tests: usb2 and usb3, link >> layer >> > testing and MSC tests) and using USB2 X CV (ch9 tests, MSC tests). >> > >> > After the patch, the tests timeout! >> > ./testusb -t 14 -c 1 -s 514 -v 1 >> > unknown speed /dev/bus/usb/001/018 0 >> > /dev/bus/usb/001/018 test 14 --> 110 (Connection timed out) >> > >> > IMO a patch to fix this is required for stable releases too. So If this >> > patch is alright, I can post the patch cc'ing stable. While the actual >> fix >> > would be to have chained TRB, I'm not sure if it can go to stable >> > releases. >> > 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 2ef3c8d..8858c60 100644 >> > --- a/drivers/usb/dwc3/ep0.c >> > +++ b/drivers/usb/dwc3/ep0.c >> > @@ -816,6 +816,11 @@ 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; >> > + >> >> Can you just use maxp in the correct way? > > > what do you mean by correct way? Using roundup() to calculate transfer_size? > just a max Michael > Thanks > Kishon -- | Michael Nazzareno Trimarchi Amarula Solutions BV | | COO - Founder Cruquiuskade 47 | | +31(0)851119172 Amsterdam 1018 AM NL | | [`as] http://www.amarulasolutions.com | -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
