The function handle_control_request() casts the urb buffer to a char *,
and then treats it like a unsigned char buffer when assigning data to
it. On some architectures, "char" is really signed, so let's just
properly set this pointer to a u8 to take away any potential problems as
that's what is really wanted here.
Use put_unaligned_le16() to copy the full 16bits into the buffer,
it's not a problem just yet as only 7 bits are being used here, but this
protects us when/if the USB spec changes in the future to define more of
these bits.
Cc: Felipe Balbi <balbi@xxxxxxxxxx>
Cc: Jakob Koschel <jakobkoschel@xxxxxxxxx>
Cc: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Ira Weiny <ira.weiny@xxxxxxxxx>
Cc: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
v2: - use put_unaligned_le16() on Linus's recommendation as a simpler and
more obvious way to describe the data being copied here.
- update device: comment based on Alan's review
drivers/usb/gadget/udc/dummy_hcd.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
index 899ac9f9c279..7c59c20c8623 100644
--- a/drivers/usb/gadget/udc/dummy_hcd.c
+++ b/drivers/usb/gadget/udc/dummy_hcd.c
@@ -1740,13 +1740,13 @@ static int handle_control_request(struct dummy_hcd *dum_hcd, struct urb *urb,
if (setup->bRequestType == Dev_InRequest
|| setup->bRequestType == Intf_InRequest
|| setup->bRequestType == Ep_InRequest) {
- char *buf;
+ u8 *buf;
/*
- * device: remote wakeup, selfpowered
+ * device: remote wakeup, selfpowered, LTM, U1, or U2
* interface: nothing
* endpoint: halt
*/
- buf = (char *)urb->transfer_buffer;
+ buf = urb->transfer_buffer;
if (urb->transfer_buffer_length > 0) {
if (setup->bRequestType == Ep_InRequest) {
ep2 = find_endpoint(dum, w_index);
@@ -1755,10 +1755,9 @@ static int handle_control_request(struct dummy_hcd *dum_hcd, struct urb *urb,
break;
}
buf[0] = ep2->halted;
- } else if (setup->bRequestType ==
- Dev_InRequest) {
- buf[0] = (u8)dum->devstatus;
- } else
+ } else if (setup->bRequestType == Dev_InRequest)
+ put_unaligned_le16(dum->devstatus, buf);
+ else
buf[0] = 0;
}
if (urb->transfer_buffer_length > 1)
--
2.38.1
