netrom: fix info leak via msg_name in nr_recvmsg()
authorMathias Krause <minipli@googlemail.com>
Sun, 7 Apr 2013 01:51:57 +0000 (01:51 +0000)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Wed, 1 May 2013 16:41:05 +0000 (09:41 -0700)
commitcd5e3d9ff117b6cff7a82b076be20dc91eec3f4f
tree2a86cd6125faf1ae2d4436bbca4163e8af24940a
parent40aea043862dd46aa865587223e084da2e3e37cf
netrom: fix info leak via msg_name in nr_recvmsg()

[ Upstream commits 3ce5efad47b62c57a4f5c54248347085a750ce0e and
  c802d759623acbd6e1ee9fbdabae89159a513913 ]

In case msg_name is set the sockaddr info gets filled out, as
requested, but the code fails to initialize the padding bytes of
struct sockaddr_ax25 inserted by the compiler for alignment. Also
the sax25_ndigis member does not get assigned, leaking four more
bytes.

Both issues lead to the fact that the code will leak uninitialized
kernel stack bytes in net/socket.c.

Fix both issues by initializing the memory with memset(0).

Signed-off-by: Mathias Krause <minipli@googlemail.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/netrom/af_netrom.c