Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers""

Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers""

This reverts commit 168508dc2278e7f9bfed0f3189d8d41bcb663e96.

As mentioned in https://lkml.org/lkml/2021/9/13/1819
5 years old commit 49587447b55d ("ipv4: fix memory leaks in ip_cmsg_send() callers")
was a correct fix.

  ip_cmsg_send() can loop over multiple cmsghdr()

  If IP_RETOPTS has been successful, but following cmsghdr generates an error,
  we do not free ipc.ok

  If IP_RETOPTS is not successful, we have freed the allocated temporary space,
  not the one currently in ipc.opt.

Sure, code could be refactored, but let's not bring back old bugs.

Fixes: 168508dc2278 ("Revert "ipv4: fix memory leaks in ip_cmsg_send() callers"")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Yajun Deng <yajun.deng@linux.dev>
Signed-off-by: David S. Miller <davem@davemloft.net>