From: Greg KH <gre...@linuxfoundation.org>

3.5-stable review patch.  If anyone has any objections, please let me know.

------------------


From: Mathias Krause <mini...@googlemail.com>

[ Upstream commits a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc
  and 8bbb181308bc348e02bfdbebdedd4e4ec9d452ce ]

The tun module leaks up to 36 bytes of memory by not fully initializing
a structure located on the stack that gets copied to user memory by the
TUNGETIFF and SIOCGIFHWADDR ioctl()s.

Signed-off-by: Mathias Krause <mini...@googlemail.com>
Signed-off-by: David S. Miller <da...@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
---
 drivers/net/tun.c |    6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1255,10 +1255,12 @@ static long __tun_chr_ioctl(struct file
        int vnet_hdr_sz;
        int ret;
 
-       if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89)
+       if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) {
                if (copy_from_user(&ifr, argp, ifreq_len))
                        return -EFAULT;
-
+       } else {
+               memset(&ifr, 0, sizeof(ifr));
+       }
        if (cmd == TUNGETFEATURES) {
                /* Currently this just means: "what IFF flags are valid?".
                 * This is needed because we never checked for invalid flags on


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