From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org
Subject: Re: [PATCH v8 3/6] tracefs: Check file permission even if user has CAP_DAC_OVERRIDE
Date: Thu, 12 Feb 2026 15:15:15 +0900 [thread overview]
Message-ID: <20260212151515.b384ac24de9b736d10387d21@kernel.org> (raw)
In-Reply-To: <20260211104623.73fd4fc3@fedora>
On Wed, 11 Feb 2026 10:46:23 -0500
Steven Rostedt <rostedt@goodmis.org> wrote:
> On Tue, 10 Feb 2026 17:43:51 +0900
> "Masami Hiramatsu (Google)" <mhiramat@kernel.org> wrote:
>
> > From: Masami Hiramatsu (Google) <mhiramat@kernel.org>
> >
> > Strictly checking the file read/write permission even if the owner has
> > CAP_DAC_OVERRIDE on tracefs as same as sysfs.
> > Tracefs is a pseudo filesystem, just like sysfs, so any file that the
> > system defines as unwritable should actually be unwritable by anyone.
>
> This is getting too complex and still doesn't work. As I said in my
> other email, simply check for the trace_array being readonly on opens()
> and return -EACCES if it is and was opened for write or read-write.
yeah, I understand I confused "permission" and "possibility".
>
> With this still not working this late in the game, it will need to wait
> until the next merge window. I'll take the first two patches of this
> series now though.
OK. I will send the next version without the first 2 patches.
Thank you,
>
> -- Steve
>
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>
next prev parent reply other threads:[~2026-02-12 6:15 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-02-10 8:43 [PATCH v8 0/6] tracing: Remove backup instance after read all Masami Hiramatsu (Google)
2026-02-10 8:43 ` [PATCH v8 1/6] tracing: Fix to set write permission to per-cpu buffer_size_kb Masami Hiramatsu (Google)
2026-02-10 8:43 ` [PATCH v8 2/6] tracing: Reset last_boot_info if ring buffer is reset Masami Hiramatsu (Google)
2026-02-10 8:43 ` [PATCH v8 3/6] tracefs: Check file permission even if user has CAP_DAC_OVERRIDE Masami Hiramatsu (Google)
2026-02-11 15:46 ` Steven Rostedt
2026-02-12 6:15 ` Masami Hiramatsu [this message]
2026-03-05 17:33 ` Steven Rostedt
2026-03-24 16:43 ` Steven Rostedt
2026-02-10 8:43 ` [PATCH v8 4/6] tracing: Make the backup instance non-reusable Masami Hiramatsu (Google)
2026-02-10 8:44 ` [PATCH v8 5/6] tracing: Remove the backup instance automatically after read Masami Hiramatsu (Google)
2026-02-10 8:44 ` [PATCH v8 6/6] tracing/Documentation: Add a section about backup instance Masami Hiramatsu (Google)
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