From: Kees Cook <keescook@chromium.org>
To: Suren Baghdasaryan <surenb@google.com>
Cc: akpm@linux-foundation.org, jannh@google.com, jeffv@google.com,
minchan@kernel.org, mhocko@suse.com, shakeelb@google.com,
rientjes@google.com, edgararriaga@google.com,
timmurray@google.com, linux-mm@kvack.org,
selinux@vger.kernel.org, linux-api@vger.kernel.org,
linux-kernel@vger.kernel.org, kernel-team@android.com
Subject: Re: [PATCH v2 1/1] mm/madvise: replace ptrace attach requirement for process_madvise
Date: Mon, 11 Jan 2021 10:33:38 -0800 [thread overview]
Message-ID: <202101111033.2D03EA97@keescook> (raw)
In-Reply-To: <20210111170622.2613577-1-surenb@google.com>
On Mon, Jan 11, 2021 at 09:06:22AM -0800, Suren Baghdasaryan wrote:
> process_madvise currently requires ptrace attach capability.
> PTRACE_MODE_ATTACH gives one process complete control over another
> process. It effectively removes the security boundary between the
> two processes (in one direction). Granting ptrace attach capability
> even to a system process is considered dangerous since it creates an
> attack surface. This severely limits the usage of this API.
> The operations process_madvise can perform do not affect the correctness
> of the operation of the target process; they only affect where the data
> is physically located (and therefore, how fast it can be accessed).
> What we want is the ability for one process to influence another process
> in order to optimize performance across the entire system while leaving
> the security boundary intact.
> Replace PTRACE_MODE_ATTACH with a combination of PTRACE_MODE_READ
> and CAP_SYS_NICE. PTRACE_MODE_READ to prevent leaking ASLR metadata
> and CAP_SYS_NICE for influencing process performance.
>
> Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
--
Kees Cook
next prev parent reply other threads:[~2021-01-11 18:33 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-11 17:06 [PATCH v2 1/1] mm/madvise: replace ptrace attach requirement for process_madvise Suren Baghdasaryan
2021-01-11 18:33 ` Kees Cook [this message]
2021-01-12 1:22 ` Andrew Morton
2021-01-12 17:36 ` Suren Baghdasaryan
2021-01-12 7:46 ` Michal Hocko
2021-01-12 17:45 ` Oleg Nesterov
2021-01-12 17:51 ` Suren Baghdasaryan
2021-01-13 14:22 ` Michal Hocko
2021-01-13 18:08 ` Suren Baghdasaryan
2021-01-20 13:17 ` Jann Horn
2021-01-20 16:57 ` Suren Baghdasaryan
2021-01-20 20:46 ` Suren Baghdasaryan
2021-01-26 13:52 ` Michal Hocko
2021-01-28 19:51 ` Suren Baghdasaryan
2021-01-29 7:08 ` Suren Baghdasaryan
2021-02-02 5:34 ` Suren Baghdasaryan
[not found] ` <CAJuCfpEOE8=L1fT4FSauy65cS82M_kW3EzTgH89ewE9HudL=VA@mail.gmail.com>
2021-03-03 0:17 ` Andrew Morton
2021-03-03 0:19 ` Suren Baghdasaryan
2021-03-03 19:00 ` Suren Baghdasaryan
2021-01-12 18:12 ` Suren Baghdasaryan
2021-01-13 14:19 ` Michal Hocko
2021-01-20 5:01 ` James Morris
2021-01-20 16:49 ` Suren Baghdasaryan
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=202101111033.2D03EA97@keescook \
--to=keescook@chromium.org \
--cc=akpm@linux-foundation.org \
--cc=edgararriaga@google.com \
--cc=jannh@google.com \
--cc=jeffv@google.com \
--cc=kernel-team@android.com \
--cc=linux-api@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=mhocko@suse.com \
--cc=minchan@kernel.org \
--cc=rientjes@google.com \
--cc=selinux@vger.kernel.org \
--cc=shakeelb@google.com \
--cc=surenb@google.com \
--cc=timmurray@google.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).