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From: Oleg Nesterov <oleg@redhat.com>
To: Jann Horn <jannh@google.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>,
	Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Arjan van de Ven <arjan@linux.intel.com>,
	"Eric W. Biederman" <ebiederm@xmission.com>,
	Jake Edge <jake@lwn.net>,
	linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org,
	stable@vger.kernel.org, Kees Cook <keescook@chromium.org>
Subject: Re: [PATCH 1/2] proc: protect ptrace_may_access() with exec_update_lock (part 1)
Date: Tue, 26 May 2026 20:22:10 +0200	[thread overview]
Message-ID: <ahXk0lBmeewqINHh@redhat.com> (raw)
In-Reply-To: <CAG48ez0RXFp6nFfOOz0MeQMPknnCPeBj9j1ndR6kL9oE=ZSc=A@mail.gmail.com>

On 05/26, Jann Horn wrote:
>
> On Tue, May 26, 2026 at 10:48 AM Oleg Nesterov <oleg@redhat.com> wrote:
> > On 05/18, Jann Horn wrote:
> > >
> > > Fix the easy cases where procfs currently calls ptrace_may_access() without
> > > exec_update_lock protection, where the fix is to simply add the extra lock
> > > or use mm_access():
> >
> > I thought about this too, but I do not know if it is fine performance wise...
> >
> > And what about proc_coredump_filter_write() which doesn't use ptrace_may_access() ?
>
> Yeah, this series doesn't fix everything,

Aah... Of course, I understand. I wasn't clear. Sorry if it looked as
"you missed proc_coredump_filter_write" from my side.

What I actually tried to ask:

	- Do you think it makes sense to fix proc_coredump_filter_write()
	  as well?

	- If yes. Do you think we should add another down_read(exec_update_lock) +
	  ptrace_may_access() into proc_coredump_filter_write() ? Or perhaps we
	  should discuss other approaches (exec_id/seqcount/etc) from the very
	  beginning?

Oleg.


  reply	other threads:[~2026-05-26 18:22 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-05-18 16:35 [PATCH 0/2] proc: protect ptrace_may_access() with exec_update_lock Jann Horn
2026-05-18 16:35 ` [PATCH 1/2] proc: protect ptrace_may_access() with exec_update_lock (part 1) Jann Horn
2026-05-26  8:48   ` Oleg Nesterov
2026-05-26  9:44     ` Oleg Nesterov
2026-05-26 14:19       ` Jann Horn
2026-05-26 14:16     ` Jann Horn
2026-05-26 18:22       ` Oleg Nesterov [this message]
2026-05-26 18:30         ` Jann Horn
2026-05-18 16:35 ` [PATCH 2/2] proc: protect ptrace_may_access() with exec_update_lock (FD links) Jann Horn
2026-05-22 11:47 ` [PATCH 0/2] proc: protect ptrace_may_access() with exec_update_lock Christian Brauner
2026-05-25 19:56 ` Eric W. Biederman
2026-05-26 11:10   ` Oleg Nesterov
2026-05-26 18:22   ` Jann Horn

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