From fe0410c7f43e133e156e54e3156392e800bedc21 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Fri, 29 Jul 2005 12:16:58 -0700 Subject: [PATCH] [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 Signed-off-by: Greg Kroah-Hartman Signed-off-by: Linus Torvalds --- drivers/usb/core/devio.c | 18 ++++++++++++------ 1 file changed, 12 insertions(+), 6 deletions(-) diff --git a/drivers/usb/core/devio.c b/drivers/usb/core/devio.c index 787c27a63c51..f86bf1454e21 100644 --- a/drivers/usb/core/devio.c +++ b/drivers/usb/core/devio.c @@ -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) -- GitLab