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USB: fix usbfs regression

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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>
CC: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Alan Stern 2010-03-06 15:04:03 -05:00 committed by Greg Kroah-Hartman
parent a3d3203e4b
commit 7152b59259
1 changed files with 14 additions and 3 deletions
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17
drivers/usb/core/devio.c
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@ -1207,6 +1207,13 @@ static int proc_do_submiturb(struct dev_state *ps, struct usbdevfs_urb *uurb,
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) |
@ -1345,10 +1352,14 @@ static int processcompl(struct async *as, void __user * __user *arg)
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))