From stern@rowland.harvard.edu Mon Jul 4 10:10:36 2005 Date: Mon, 4 Jul 2005 10:08:24 -0400 (EDT) From: Alan Stern To: Greg KH Subject: USB: usbfs: Don't leak uninitialized data Message-ID: 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/core/devio.c | 18 ++++++++++++------ 1 files changed, 12 insertions(+), 6 deletions(-) --- gregkh-2.6.orig/drivers/usb/core/devio.c 2005-07-27 15:20:56.000000000 -0700 +++ gregkh-2.6/drivers/usb/core/devio.c 2005-07-27 15:25:47.000000000 -0700 @@ -569,8 +569,11 @@ 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 @@ 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 @@ 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)