Re: [PATCH v11 07/12] seccomp: add SECCOMP_RET_ERRNO
From: Oleg Nesterov <oleg@redhat.com>
Date: 2012-02-27 18:22:08
Also in:
linux-arch, lkml
On 02/27, Kees Cook wrote:
On Mon, Feb 27, 2012 at 9:11 AM, Oleg Nesterov [off-list ref] wrote:quoted
On 02/24, Will Drewry wrote:quoted
static u32 seccomp_run_filters(int syscall) { struct seccomp_filter *f; - u32 ret = SECCOMP_RET_KILL; static const struct bpf_load_fn fns = { bpf_load, sizeof(struct seccomp_data), }; + u32 ret = SECCOMP_RET_ALLOW; const void *sc_ptr = (const void *)(uintptr_t)syscall; + /* Ensure unexpected behavior doesn't result in failing open. */ + if (unlikely(current->seccomp.filter == NULL)) + ret = SECCOMP_RET_KILL;Is "seccomp.filter == NULL" really possible?It should not be, but I'm much more comfortable with this failing closed. I think it's important to be as defensive as possible with this code given its intended use.
Can't resists... Sorry, I know I am troll but personally I think in this case the most defensive code is BUG_ON(->filter == NULL) or at least WARN_ON(). Nevermind, I won't pretend I really understand the intended use, please ignore. Oleg.