Feeding 32-bit length cast down to 'u16' to min() to calculate the FIFO count
in musb_host_tx() risks sending a short packet prematurely for transfer sizes
over 64 KB. And although data transfer size shouldn't exceed 65535 bytes for
the control endpoint, making musb_h_ep0_continue() more robust WRT URBs with
possibly oversized buffer will not hurt either...
Signed-off-by: Sergei Shtylyov <sshtylyov@xxxxxxxxxxxxx>
---
The patch is against the recent Linus' kernel.
drivers/usb/musb/musb_host.c | 13 +++++++------
1 files changed, 7 insertions(+), 6 deletions(-)
Index: linux-2.6/drivers/usb/musb/musb_host.c
===================================================================
--- linux-2.6.orig/drivers/usb/musb/musb_host.c
+++ linux-2.6/drivers/usb/musb/musb_host.c
@@ -936,8 +936,8 @@ static bool musb_h_ep0_continue(struct m
switch (musb->ep0_stage) {
case MUSB_EP0_IN:
fifo_dest = urb->transfer_buffer + urb->actual_length;
- fifo_count = min(len, ((u16) (urb->transfer_buffer_length
- - urb->actual_length)));
+ fifo_count = min_t(size_t, len, urb->transfer_buffer_length -
+ urb->actual_length);
if (fifo_count < len)
urb->status = -EOVERFLOW;
@@ -970,9 +970,9 @@ static bool musb_h_ep0_continue(struct m
}
/* FALLTHROUGH */
case MUSB_EP0_OUT:
- fifo_count = min(qh->maxpacket, ((u16)
- (urb->transfer_buffer_length
- - urb->actual_length)));
+ fifo_count = min_t(size_t, qh->maxpacket,
+ urb->transfer_buffer_length -
+ urb->actual_length);
if (fifo_count) {
fifo_dest = (u8 *) (urb->transfer_buffer
@@ -1303,7 +1303,8 @@ void musb_host_tx(struct musb *musb, u8
* packets before updating TXCSR ... other docs disagree ...
*/
/* PIO: start next packet in this URB */
- wLength = min(qh->maxpacket, (u16) wLength);
+ if (wLength > qh->maxpacket)
+ wLength = qh->maxpacket;
musb_write_fifo(hw_ep, wLength, buf);
qh->segsize = wLength;
--
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