Messages in this thread Patch in this message | | | Date | Tue, 30 Mar 2010 15:55:41 -0700 | From | Greg KH <> | Subject | [063/116] USB: fix usbfs regression |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Alan Stern <stern@rowland.harvard.edu>
commit 7152b592593b9d48b33f8997b1dfd6df9143f7ec upstream.
This patch (as1352) fixes a bug in the way isochronous input data is returned to userspace for usbfs transfers. The entire buffer must be copied, not just the first actual_length bytes, because the individual packets will be discontiguous if any of them are short.
Reported-by: Markus Rechberger <mrechberger@gmail.com> Signed-off-by: Alan Stern <stern@rowland.harvard.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- drivers/usb/core/devio.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)
--- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -1176,6 +1176,13 @@ static int proc_do_submiturb(struct dev_ free_async(as); return -ENOMEM; } + /* Isochronous input data may end up being discontiguous + * if some of the packets are short. Clear the buffer so + * that the gaps don't leak kernel data to userspace. + */ + if (is_in && uurb->type == USBDEVFS_URB_TYPE_ISO) + memset(as->urb->transfer_buffer, 0, + uurb->buffer_length); } as->urb->dev = ps->dev; as->urb->pipe = (uurb->type << 30) | @@ -1312,10 +1319,14 @@ static int processcompl(struct async *as void __user *addr = as->userurb; unsigned int i; - if (as->userbuffer && urb->actual_length) - if (copy_to_user(as->userbuffer, urb->transfer_buffer, - urb->actual_length)) + if (as->userbuffer && urb->actual_length) { + if (urb->number_of_packets > 0) /* Isochronous */ + i = urb->transfer_buffer_length; + else /* Non-Isoc */ + i = urb->actual_length; + if (copy_to_user(as->userbuffer, urb->transfer_buffer, i)) goto err_out; + } if (put_user(as->status, &userurb->status)) goto err_out; if (put_user(urb->actual_length, &userurb->actual_length))
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