Re: CVE-2026-89603: entry: Fix seccomp bypass after ptrace with TSYNC

[Oleg Nesterov]

On 10/15, Kees Cook wrote:
>
> On Fri, Sep 11, 2026 at 09:44:52PM +0200, Greg Kroah-Hartman wrote:
> > This race condition could allow an unprivileged process to execute
> > a prohibited system call (e.g., execve) that the newly installed filter
> > was intended to block, especially since the tracer might have modified
> > the system call number during the ptrace stop.
>
> I'm disputing this one: please reject CVE-2026-89603. The fix is a fine
> consistency change, but the flaw gave neither the tracer nor the tracee
> anything they didn't already have.

Thanks Kees!

I fully agree with both points. The patch is fine, but it doesn't fix
any security problem.

Oleg.