usb: misc: sisusbvga: fix information leak to userland

commit 5dc92cf1d0b4b0debbd2e333b83f9746c103533d upstream.

Structure sisusb_info is copied to userland with "sisusb_reserved" field
uninitialized.  It leads to leaking of contents of kernel stack memory.

Signed-off-by: Vasiliy Kulikov <segooon@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/drivers/usb/misc/sisusbvga/sisusb.c b/drivers/usb/misc/sisusbvga/sisusb.c
index cf13923ef5e162ac003af8b78f0a378aa5b6c77e..ba0a0bb46701cf648a0036a6645a4b382a9fa65a 100644 (file)
--- a/drivers/usb/misc/sisusbvga/sisusb.c
+++ b/drivers/usb/misc/sisusbvga/sisusb.c
@@ -3018,6 +3018,7 @@ sisusb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 #else
                        x.sisusb_conactive  = 0;
 #endif
+                       memset(x.sisusb_reserved, 0, sizeof(x.sisusb_reserved));
 
                        if (copy_to_user((void __user *)arg, &x, sizeof(x)))
                                retval = -EFAULT;