USB: usbfs: only copy the actual data received

We need to only copy the data received by the device to userspace, not
the whole kernel buffer, which can contain "stale" data.

Thanks to Marcus Meissner for pointing this out and testing the fix.

Reported-by: Marcus Meissner <meissner@suse.de>
Tested-by: Marcus Meissner <meissner@suse.de>
Cc: Alan Stern <stern@rowland.harvard.edu>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
This commit is contained in:
Greg KH 2010-02-15 09:37:46 -08:00 committed by Greg Kroah-Hartman
parent 0813e22d4e
commit d4a4683ca0
1 changed files with 4 additions and 4 deletions

View File

@ -1312,9 +1312,9 @@ static int processcompl(struct async *as, void __user * __user *arg)
void __user *addr = as->userurb;
unsigned int i;
if (as->userbuffer)
if (as->userbuffer && urb->actual_length)
if (copy_to_user(as->userbuffer, urb->transfer_buffer,
urb->transfer_buffer_length))
urb->actual_length))
goto err_out;
if (put_user(as->status, &userurb->status))
goto err_out;
@ -1475,9 +1475,9 @@ static int processcompl_compat(struct async *as, void __user * __user *arg)
void __user *addr = as->userurb;
unsigned int i;
if (as->userbuffer)
if (as->userbuffer && urb->actual_length)
if (copy_to_user(as->userbuffer, urb->transfer_buffer,
urb->transfer_buffer_length))
urb->actual_length))
return -EFAULT;
if (put_user(as->status, &userurb->status))
return -EFAULT;