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    Subject[PATCH 4.7 136/141] usb: usbip: vudc: fix left shift overflow
    Date
    4.7-stable review patch.  If anyone has any objections, please let me know.

    ------------------

    From: Nicolas Iooss <nicolas.iooss_linux@m4x.org>

    commit 238b7bd91b16d5a08326f858db42229b212e53d8 upstream.

    In v_recv_cmd_submit(), urb_p->urb->pipe has the type unsigned int
    (which is 32-bit long on x86_64) but 11<<30 results in a 34-bit integer.
    Therefore the 2 leading bits are truncated and

    urb_p->urb->pipe &= ~(11 << 30);

    has the same meaning as

    urb_p->urb->pipe &= ~(3 << 30);

    This second statement seems to be how the code was intended to be
    written, as PIPE_ constants have values between 0 and 3.

    The overflow has been detected with a clang warning:

    drivers/usb/usbip/vudc_rx.c:145:27: warning: signed shift result
    (0x2C0000000) requires 35 bits to represent, but 'int' only has 32
    bits [-Wshift-overflow]
    urb_p->urb->pipe &= ~(11 << 30);
    ~~ ^ ~~

    Fixes: 79c02cb1fd5c ("usbip: vudc: Add vudc_rx")
    Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
    Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

    ---
    drivers/usb/usbip/vudc_rx.c | 2 +-
    1 file changed, 1 insertion(+), 1 deletion(-)

    --- a/drivers/usb/usbip/vudc_rx.c
    +++ b/drivers/usb/usbip/vudc_rx.c
    @@ -142,7 +142,7 @@ static int v_recv_cmd_submit(struct vudc
    urb_p->urb->status = -EINPROGRESS;

    /* FIXME: more pipe setup to please usbip_common */
    - urb_p->urb->pipe &= ~(11 << 30);
    + urb_p->urb->pipe &= ~(3 << 30);
    switch (urb_p->ep->type) {
    case USB_ENDPOINT_XFER_BULK:
    urb_p->urb->pipe |= (PIPE_BULK << 30);

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