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Wed, 25 Sep 2024 08:58:09 -0700 (PDT) Received: from p183 ([46.53.252.51]) by smtp.gmail.com with ESMTPSA id a640c23a62f3a-a93930f7860sm228237066b.149.2024.09.25.08.58.07 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 25 Sep 2024 08:58:08 -0700 (PDT) Date: Wed, 25 Sep 2024 18:58:05 +0300 From: Alexey Dobriyan To: Sasha Levin Cc: linux-kernel@vger.kernel.org, stable@vger.kernel.org, Adrian Ratiu , Doug Anderson , Jeff Xu , Jann Horn , Kees Cook , Ard Biesheuvel , Christian Brauner , Linus Torvalds , corbet@lwn.net, paul@paul-moore.com, jmorris@namei.org, serge@hallyn.com, thuth@redhat.com, bp@alien8.de, tglx@linutronix.de, jpoimboe@kernel.org, paulmck@kernel.org, tony@atomide.com, xiongwei.song@windriver.com, akpm@linux-foundation.org, oleg@redhat.com, casey@schaufler-ca.com, viro@zeniv.linux.org.uk, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-security-module@vger.kernel.org Subject: Re: [PATCH AUTOSEL 6.6 048/139] proc: add config & param to block forcing mem writes Message-ID: References: <20240925121137.1307574-1-sashal@kernel.org> <20240925121137.1307574-48-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-doc@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20240925121137.1307574-48-sashal@kernel.org> On Wed, Sep 25, 2024 at 08:07:48AM -0400, Sasha Levin wrote: > From: Adrian Ratiu > > [ Upstream commit 41e8149c8892ed1962bd15350b3c3e6e90cba7f4 ] > > This adds a Kconfig option and boot param to allow removing > the FOLL_FORCE flag from /proc/pid/mem write calls because > it can be abused. And this is not a mount option why? > The traditional forcing behavior is kept as default because > it can break GDB and some other use cases. > > Previously we tried a more sophisticated approach allowing > distributions to fine-tune /proc/pid/mem behavior, however > that got NAK-ed by Linus [1], who prefers this simpler > approach with semantics also easier to understand for users.