net/tun: fix ioctl() based info leaks
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>
diff --git a/drivers/net/tun.c b/drivers/net/tun.c
index c62163e..f55c462 100644
--- a/drivers/net/tun.c
+++ b/drivers/net/tun.c
@@ -1379,9 +1379,11 @@
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?".