Re: [PATCH v14] exec: Fix dead-lock in de_thread with ptrace_attach

On Tue, Jan 23, 2024 at 07:30:52PM +0100, Bernd Edlinger wrote:

• Currently a non-privileged program can potentially send such a privileged

tracer into a deadlock.

• With the alternative patch below that non-privileged can no longer send the

tracer into a deadlock, but it can still quickly escape out of the tracer's control.

• But with my latest patch a sufficiently privileged tracer can neither be

sent into a deadlock nor can the attached process escape. Mission completed.

Thanks for the details. And it would be pretty unfriendly to fail the execve() too (or, rather, it makes the execve failure unpredictable). I'll keep reading your patch...