ipv4: check optlen for IP_MULTICAST_IF option
authorShan Wei <shanwei@cn.fujitsu.com>
Tue, 22 Sep 2009 15:41:10 +0000 (15:41 +0000)
committerDavid S. Miller <davem@davemloft.net>
Thu, 24 Sep 2009 22:38:44 +0000 (15:38 -0700)
commit0915921bde4eb5d943b17c175febac58a254d7b6
treecd6a6845d0a340f4aa06a3b5f28118ae8d7e66bb
parent8b3f6af86378d0a10ca2f1ded1da124aef13b62c
ipv4: check optlen for IP_MULTICAST_IF option

Due to man page of setsockopt, if optlen is not valid, kernel should return
-EINVAL. But a simple testcase as following, errno is 0, which means setsockopt
is successful.
addr.s_addr = inet_addr("192.1.2.3");
setsockopt(s, IPPROTO_IP, IP_MULTICAST_IF, &addr, 1);
printf("errno is %d\n", errno);

Xiaotian Feng(dfeng@redhat.com) caught the bug. We fix it firstly checking
the availability of optlen and then dealing with the logic like other options.

Reported-by: Xiaotian Feng <dfeng@redhat.com>
Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Acked-by: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/ipv4/ip_sockglue.c