| Message ID | 1554820632-13782-1-git-send-email-zhuyan34@huawei.com (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | usb:host: fix divide-by-zero in function fhci_queue_urb | expand |
On Tue, Apr 09, 2019 at 10:37:12PM +0800, zhuyan wrote: > In function fhci_queue_urb, the divisor of expression > (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe, > usb_pipeout(urb->pipe))) may be zero. How can you hit that? > When it is zero, unexpected results may occur, so it is necessary to > ensure that the divisor is not zero. > > Signed-off-by: zhuyan <zhuyan34@huawei.com> I need a "Full" name here, not just a single name. Whatever you use to sign documents is good. thanks, greg k-h
diff --git a/drivers/usb/host/fhci-sched.c b/drivers/usb/host/fhci-sched.c index 3d12cdd..27ed63c 100644 --- a/drivers/usb/host/fhci-sched.c +++ b/drivers/usb/host/fhci-sched.c @@ -704,6 +704,7 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb) struct td *td; u8 *data; u16 cnt = 0; + u16 max_pkt_size = 0; if (ed == NULL) { ed = fhci_get_empty_ed(fhci); @@ -765,11 +766,13 @@ void fhci_queue_urb(struct fhci_hcd *fhci, struct urb *urb) switch (ed->mode) { case FHCI_TF_BULK: + max_pkt_size = usb_maxpacket(urb->dev, urb->pipe, + usb_pipeout(urb->pipe)); if (urb->transfer_flags & URB_ZERO_PACKET && urb->transfer_buffer_length > 0 && + (max_pkt_size != 0) && ((urb->transfer_buffer_length % - usb_maxpacket(urb->dev, urb->pipe, - usb_pipeout(urb->pipe))) == 0)) + max_pkt_size) == 0)) urb_state = US_BULK0; while (data_len > 4096) { td = fhci_td_fill(fhci, urb, urb_priv, ed, cnt,
In function fhci_queue_urb, the divisor of expression (urb->transfer_buffer_length % usb_maxpacket(urb->dev, urb->pipe, usb_pipeout(urb->pipe))) may be zero. When it is zero, unexpected results may occur, so it is necessary to ensure that the divisor is not zero. Signed-off-by: zhuyan <zhuyan34@huawei.com> --- drivers/usb/host/fhci-sched.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-)