4.19-stable review patch. If anyone has any objections, please let me know.
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From: Chris Wulff Chris.Wulff@biamp.com
commit 0aea736ddb877b93f6d2dd8cf439840d6b4970a9 upstream.
If the USB driver passes a pointer into the TRB buffer for creq, this buffer can be overwritten with the status response as soon as the event is queued. This can make the final check return USB_GADGET_DELAYED_STATUS when it shouldn't. Instead use the stored wLength.
Fixes: 4d644abf2569 ("usb: gadget: f_fs: Only return delayed status when len is 0") Cc: stable stable@kernel.org Signed-off-by: Chris Wulff chris.wulff@biamp.com Link: https://lore.kernel.org/r/CO1PR17MB5419BD664264A558B2395E28E1112@CO1PR17MB54... Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/gadget/function/f_fs.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/drivers/usb/gadget/function/f_fs.c +++ b/drivers/usb/gadget/function/f_fs.c @@ -3304,7 +3304,7 @@ static int ffs_func_setup(struct usb_fun __ffs_event_add(ffs, FUNCTIONFS_SETUP); spin_unlock_irqrestore(&ffs->ev.waitq.lock, flags);
- return creq->wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; + return ffs->ev.setup.wLength == 0 ? USB_GADGET_DELAYED_STATUS : 0; }
static bool ffs_func_req_match(struct usb_function *f,