Messages in this thread | | | Date | Tue, 27 Apr 2021 08:26:20 +0200 | From | Oleg Nesterov <> | Subject | Re: [PATCH RESEND] ptrace: make ptrace() fail if the tracee changed its pid unexpectedly |
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Hi Mathieu,
On 04/26, Mathieu Desnoyers wrote: > > > The patch doesn't add the new PTRACE_ option to not complicate the API, > > and I _hope_ this won't cause any noticeable regression: > > > > - If debugger uses PTRACE_O_TRACEEXEC and the thread did an exec > > and the tracer does a ptrace request without having consumed > > the exec event, it's 100% sure that the thread the ptracer > > thinks it is targeting does not exist anymore, or isn't the > > same as the one it thinks it is targeting. > > > > - To some degree this patch adds nothing new. In the scenario > > above ptrace(L) can fail with -ESRCH if it is called after the > > execing sub-thread wakes the leader up and before it "steals" > > the leader's pid. > > Hi Oleg, > > Is this something that should also target stable kernels ? AFAIU this change > won't break debuggers more that they are already in this scenario. Or maybe > it makes them fail in more obvious ways ?
Well, I am not sure this is stable material...
To me the problem is minor, and the patch adds the user-visible change. I think it would be safer to not add stable tag.
Oleg.
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