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[209.85.208.171]) by smtp.gmail.com with ESMTPSA id w16sm262963lfn.83.2021.09.09.10.35.09 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 09 Sep 2021 10:35:10 -0700 (PDT) Received: by mail-lj1-f171.google.com with SMTP id h1so4197626ljl.9 for ; Thu, 09 Sep 2021 10:35:09 -0700 (PDT) X-Received: by 2002:a05:651c:94:: with SMTP id 20mr846463ljq.164.1631208909475; Thu, 09 Sep 2021 10:35:09 -0700 (PDT) MIME-Version: 1.0 References: <20210907195226.14b1d22a07c085b22968b933@linux-foundation.org> <20210908025730.S88ylmikU%akpm@linux-foundation.org> In-Reply-To: From: Linus Torvalds Date: Thu, 9 Sep 2021 10:34:53 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [External] Re: [patch 079/147] fs/proc/kcore.c: add mmap interface To: Feng Zhou Cc: Andrew Morton , Alexey Dobriyan , chenying.kernel@bytedance.com, Linux-MM , mm-commits@vger.kernel.org, Mike Rapoport , Muchun Song , zhouchengming@bytedance.com, zhengqi.arch@bytedance.com Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: CB7266001980 Authentication-Results: imf14.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=google header.b=T7vayAUm; dmarc=none; spf=pass (imf14.hostedemail.com: domain of torvalds@linuxfoundation.org designates 209.85.167.48 as permitted sender) smtp.mailfrom=torvalds@linuxfoundation.org X-Stat-Signature: 6bsoda4gangawxasg3kcuusye56w6p9e X-HE-Tag: 1631208912-309179 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Sep 9, 2021 at 10:32 AM Linus Torvalds wrote: > > This is basically a very dangerous interface. The fact that it is > read-only doesn't change that at all. Just to clarify - we've done dangerous interfaces in the past. We probably have tons of them still that I haven't even thought about, and I think I can hear somebody sniggering from miles away about various bugs that cause much more obvious security holes that I didn't think of. But the fact that we might have other holes that can be misused, doesn't mean we have to add new ones that seem to be almost designed for misuse. Linus