From d4a4683ca054ed9917dfc9e3ff0f7ecf74ad90d6 Mon Sep 17 00:00:00 2001 From: Greg KH Date: Mon, 15 Feb 2010 09:37:46 -0800 Subject: [PATCH] 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 Tested-by: Marcus Meissner Cc: Alan Stern Cc: Linus Torvalds Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 6e8bcdfd23b4..ca948bbc388f 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -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; -- 2.20.1