Re: [PATCH]: SCTP length validation.

From: Vlad Yasevich <redacted>
Date: Mon, 23 Jun 2008 11:59:43 -0400

David Miller wrote:

quoted

From: Vlad Yasevich <redacted>
Date: Sat, 21 Jun 2008 11:55:19 -0400

quoted

The same vulnerability also exists in sctp_getsockopt_peer_addrs_old().
It's a bit more difficult to trigger since there is a dependency on
the peer being multihomed as well, but it's still possible to cause the
overwrite.

I can't see how that's possible.  This case looks harmless to
me.

The kernel side accesses are perfectly protected.  The kernel
will only access the actual address list stored via:

 ...

You are right.  I didn't look far enough.  Since there is no kmalloc(),
the overflow of kernel memory is not possible, and copy_to_user should
take care of any overflows of the user memory.

Thanks for double-checking my analysis Vlad.