net/tun: fix ioctl() based info leaks
[ 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 <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index a06ad55..8f13420 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1255,10 +1255,12 @@
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