USB: ehci: paranoia, reject large control transfers
Some EHCI fault paths with large control transfers aren't coded. Avoid
problems by rejecting transfers that may need two qTDs (16+ KB). This is
mostly paranoia; even 4 KB transfers are rare, and most HCDs use lower
limits (so it's unlikely anyone would ever try such a thing).
Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/host/ehci-hcd.c b/drivers/usb/host/ehci-hcd.c
index 8c3e860..a02dcff 100644
--- a/drivers/usb/host/ehci-hcd.c
+++ b/drivers/usb/host/ehci-hcd.c
@@ -764,8 +764,14 @@
INIT_LIST_HEAD (&qtd_list);
switch (usb_pipetype (urb->pipe)) {
- // case PIPE_CONTROL:
- // case PIPE_BULK:
+ case PIPE_CONTROL:
+ /* qh_completions() code doesn't handle all the fault cases
+ * in multi-TD control transfers. Even 1KB is rare anyway.
+ */
+ if (urb->transfer_buffer_length > (16 * 1024))
+ return -EMSGSIZE;
+ /* FALLTHROUGH */
+ /* case PIPE_BULK: */
default:
if (!qh_urb_transaction (ehci, urb, &qtd_list, mem_flags))
return -ENOMEM;