cvs commit: src/sys/kern uipc_syscalls.c

[Jacques A. Vidrine]

On Sat, Jan 10, 2004 at 12:28:54AM -0800, Don Lewis wrote:
> truckman    2004/01/10 00:28:54 PST
> 
>   FreeBSD src repository
> 
>   Modified files:
>     sys/kern             uipc_syscalls.c 
>   Log:
>   Add a somewhat redundant check on the len arguement to getsockaddr() to
>   avoid relying on the minimum memory allocation size to avoid problems.
>   The check is somewhat redundant because the consumers of the returned
>   structure will check that sa_len is a protocol-specific larger size.
>   
>   Submitted by:   Matthew Dillon <dillon at apollo.backplane.com>
>   Reviewed by:    nectar
>   MFC after:      30 days

But the check *is not* redundant.  The consumers cannot safely check
sa_len if the allocation were to be less than `offsetof(struct
sa_sockaddr, data[0])'--- which it never is, by chance, due to the
minimum memory allocation size, as you noted.  But we shall all feel
better that this is made explicit.  FWIW, I think the check should
have been for `sizeof(*sa)' technically, but what has been committed
is safe, too, I believe.

Cheers,
-- 
Jacques Vidrine   NTT/Verio SME      FreeBSD UNIX       Heimdal
nectar at celabo.org jvidrine at verio.net nectar at freebsd.org nectar at kth.se