USB: g_file_storage: ignore bulk-out data after invalid CBW
This patch (as1061) makes g_file_storage more compliant with the
Bulk-Only Transport specification. After an invalid CBW is received,
the gadget must ignore any further bulk-OUT data until it is reset.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/gadget/file_storage.c b/drivers/usb/gadget/file_storage.c
index 017a196..0a726e1 100644
--- a/drivers/usb/gadget/file_storage.c
+++ b/drivers/usb/gadget/file_storage.c
@@ -644,7 +644,7 @@
unsigned long atomic_bitflags;
#define REGISTERED 0
-#define CLEAR_BULK_HALTS 1
+#define IGNORE_BULK_OUT 1
#define SUSPENDED 2
struct usb_ep *bulk_in;
@@ -2936,8 +2936,8 @@
struct usb_request *req = bh->outreq;
struct bulk_cb_wrap *cbw = req->buf;
- /* Was this a real packet? */
- if (req->status)
+ /* Was this a real packet? Should it be ignored? */
+ if (req->status || test_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
return -EINVAL;
/* Is the CBW valid? */
@@ -2948,13 +2948,17 @@
req->actual,
le32_to_cpu(cbw->Signature));
- /* The Bulk-only spec says we MUST stall the bulk pipes!
- * If we want to avoid stalls, set a flag so that we will
- * clear the endpoint halts at the next reset. */
- if (!mod_data.can_stall)
- set_bit(CLEAR_BULK_HALTS, &fsg->atomic_bitflags);
- fsg_set_halt(fsg, fsg->bulk_out);
+ /* The Bulk-only spec says we MUST stall the IN endpoint
+ * (6.6.1), so it's unavoidable. It also says we must
+ * retain this state until the next reset, but there's
+ * no way to tell the controller driver it should ignore
+ * Clear-Feature(HALT) requests.
+ *
+ * We aren't required to halt the OUT endpoint; instead
+ * we can simply accept and discard any data received
+ * until the next reset. */
halt_bulk_in_endpoint(fsg);
+ set_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
return -EINVAL;
}
@@ -3140,6 +3144,7 @@
goto reset;
fsg->bulk_out_enabled = 1;
fsg->bulk_out_maxpacket = le16_to_cpu(d->wMaxPacketSize);
+ clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags);
if (transport_is_cbi()) {
d = ep_desc(fsg->gadget, &fs_intr_in_desc, &hs_intr_in_desc);
@@ -3321,11 +3326,8 @@
/* In case we were forced against our will to halt a
* bulk endpoint, clear the halt now. (The SuperH UDC
* requires this.) */
- if (test_and_clear_bit(CLEAR_BULK_HALTS,
- &fsg->atomic_bitflags)) {
+ if (test_and_clear_bit(IGNORE_BULK_OUT, &fsg->atomic_bitflags))
usb_ep_clear_halt(fsg->bulk_in);
- usb_ep_clear_halt(fsg->bulk_out);
- }
if (transport_is_bbb()) {
if (fsg->ep0_req_tag == exception_req_tag)