[PATCH] USB: usbfs: Don't leak uninitialized data

This patch fixes an information leak in the usbfs snoop facility:
uninitialized data from __get_free_page can be returned to userspace and
written to the system log.  It also improves the snoop output by printing
the wLength value.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This commit is contained in:
Alan Stern 2005-07-29 12:16:58 -07:00 committed by Linus Torvalds
parent 279e1545a1
commit fe0410c7f4

View File

@ -569,8 +569,11 @@ static int proc_control(struct dev_state *ps, void __user *arg)
free_page((unsigned long)tbuf);
return -EINVAL;
}
snoop(&dev->dev, "control read: bRequest=%02x bRrequestType=%02x wValue=%04x wIndex=%04x\n",
ctrl.bRequest, ctrl.bRequestType, ctrl.wValue, ctrl.wIndex);
snoop(&dev->dev, "control read: bRequest=%02x "
"bRrequestType=%02x wValue=%04x "
"wIndex=%04x wLength=%04x\n",
ctrl.bRequest, ctrl.bRequestType, ctrl.wValue,
ctrl.wIndex, ctrl.wLength);
usb_unlock_device(dev);
i = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0), ctrl.bRequest, ctrl.bRequestType,
@ -579,11 +582,11 @@ static int proc_control(struct dev_state *ps, void __user *arg)
if ((i > 0) && ctrl.wLength) {
if (usbfs_snoop) {
dev_info(&dev->dev, "control read: data ");
for (j = 0; j < ctrl.wLength; ++j)
for (j = 0; j < i; ++j)
printk ("%02x ", (unsigned char)(tbuf)[j]);
printk("\n");
}
if (copy_to_user(ctrl.data, tbuf, ctrl.wLength)) {
if (copy_to_user(ctrl.data, tbuf, i)) {
free_page((unsigned long)tbuf);
return -EFAULT;
}
@ -595,8 +598,11 @@ static int proc_control(struct dev_state *ps, void __user *arg)
return -EFAULT;
}
}
snoop(&dev->dev, "control write: bRequest=%02x bRrequestType=%02x wValue=%04x wIndex=%04x\n",
ctrl.bRequest, ctrl.bRequestType, ctrl.wValue, ctrl.wIndex);
snoop(&dev->dev, "control write: bRequest=%02x "
"bRrequestType=%02x wValue=%04x "
"wIndex=%04x wLength=%04x\n",
ctrl.bRequest, ctrl.bRequestType, ctrl.wValue,
ctrl.wIndex, ctrl.wLength);
if (usbfs_snoop) {
dev_info(&dev->dev, "control write: data: ");
for (j = 0; j < ctrl.wLength; ++j)