From: Kees Cook <kees@kernel.org>
To: Jeff Layton <jlayton@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>,
"David S. Miller" <davem@davemloft.net>,
Eric Dumazet <edumazet@google.com>,
Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
Simon Horman <horms@kernel.org>,
Maarten Lankhorst <maarten.lankhorst@linux.intel.com>,
Maxime Ripard <mripard@kernel.org>,
Thomas Zimmermann <tzimmermann@suse.de>,
David Airlie <airlied@gmail.com>, Simona Vetter <simona@ffwll.ch>,
Jani Nikula <jani.nikula@linux.intel.com>,
Joonas Lahtinen <joonas.lahtinen@linux.intel.com>,
Rodrigo Vivi <rodrigo.vivi@intel.com>,
Tvrtko Ursulin <tursulin@ursulin.net>,
Krzysztof Karas <krzysztof.karas@intel.com>,
Kuniyuki Iwashima <kuniyu@amazon.com>,
Qasim Ijaz <qasdev00@gmail.com>,
Nathan Chancellor <nathan@kernel.org>,
Andrew Lunn <andrew@lunn.ch>,
linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH v15 6/9] ref_tracker: automatically register a file in debugfs for a ref_tracker_dir
Date: Thu, 31 Jul 2025 09:54:21 -0700 [thread overview]
Message-ID: <202507310952.7255AA30@keescook> (raw)
In-Reply-To: <6270c853cdf90172d4794e2b601ebc88590b774f.camel@kernel.org>
On Thu, Jul 31, 2025 at 06:29:00AM -0400, Jeff Layton wrote:
> "If you think you can justify it (in comments and commit log) well
> enough to stand up to Linus’s scrutiny, maybe you can use “%px”, along
> with making sure you have sensible permissions."
>
> Is making it only accessible by root not sensible enough? What are
> "sensible permissions" in this instance?
Yes, I should have been more clear (or probably should update the
document), but root (uid==0) isn't a sufficient permission check, as
address exposure is supposed to be bounded by capabilities. Putting a
filename into the tree exposes the address to anything that can get a
file listing, and DAC access control isn't granular enough.
(Thank you again for the fix patch I saw in the other thread!)
--
Kees Cook
next prev parent reply other threads:[~2025-07-31 16:54 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-18 14:24 [PATCH v15 0/9] ref_tracker: add ability to register a debugfs file for a ref_tracker_dir Jeff Layton
2025-06-18 14:24 ` [PATCH v15 1/9] ref_tracker: don't use %pK in pr_ostream() output Jeff Layton
2025-06-18 14:24 ` [PATCH v15 2/9] ref_tracker: add a top level debugfs directory for ref_tracker Jeff Layton
2025-06-18 14:24 ` [PATCH v15 3/9] ref_tracker: have callers pass output function to pr_ostream() Jeff Layton
2025-06-23 12:57 ` Krzysztof Karas
2025-06-18 14:24 ` [PATCH v15 4/9] ref_tracker: add a static classname string to each ref_tracker_dir Jeff Layton
2025-06-23 13:21 ` Krzysztof Karas
2025-06-18 14:24 ` [PATCH v15 5/9] ref_tracker: allow pr_ostream() to print directly to a seq_file Jeff Layton
2025-06-23 14:01 ` Krzysztof Karas
2025-06-23 17:28 ` Jeff Layton
2025-06-27 12:32 ` Krzysztof Karas
2025-06-18 14:24 ` [PATCH v15 6/9] ref_tracker: automatically register a file in debugfs for a ref_tracker_dir Jeff Layton
2025-07-30 23:07 ` Kees Cook
2025-07-31 10:29 ` Jeff Layton
2025-07-31 16:54 ` Kees Cook [this message]
2025-06-18 14:24 ` [PATCH v15 7/9] ref_tracker: add a way to create a symlink to the ref_tracker_dir debugfs file Jeff Layton
2025-06-18 14:24 ` [PATCH v15 8/9] net: add symlinks to ref_tracker_dir for netns Jeff Layton
2025-06-18 14:24 ` [PATCH v15 9/9] ref_tracker: eliminate the ref_tracker_dir name field Jeff Layton
2025-06-20 0:13 ` [PATCH v15 0/9] ref_tracker: add ability to register a debugfs file for a ref_tracker_dir Jakub Kicinski
2025-06-21 6:58 ` Eric Dumazet
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