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[209.85.167.43]) by smtp.gmail.com with ESMTPSA id h13sm404349lfc.198.2021.07.02.17.15.58 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 02 Jul 2021 17:15:59 -0700 (PDT) Received: by mail-lf1-f43.google.com with SMTP id n14so21090648lfu.8 for ; Fri, 02 Jul 2021 17:15:58 -0700 (PDT) X-Received: by 2002:a19:7d04:: with SMTP id y4mr1557652lfc.201.1625271358691; Fri, 02 Jul 2021 17:15:58 -0700 (PDT) MIME-Version: 1.0 References: <20210630184624.9ca1937310b0dd5ce66b30e7@linux-foundation.org> <20210701015444.ZOZaFPX0b%akpm@linux-foundation.org> <202107021047.CC57ED634@keescook> <87pmw0ih4e.fsf@disp2133> <202107021626.913478E@keescook> In-Reply-To: <202107021626.913478E@keescook> From: Linus Torvalds Date: Fri, 2 Jul 2021 17:15:42 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [patch 142/192] procfs: allow reading fdinfo with PTRACE_MODE_READ To: Kees Cook Cc: "Eric W. Biederman" , Andrew Morton , Alexey Dobriyan , Andrei Vagin , Bernd Edlinger , Christian Brauner , Christian Koenig , Jonathan Corbet , Helge Deller , Alexey Gladkov , Hridya Valsaraju , jamorris@linux.microsoft.com, Jann Horn , Jeff Vander Stoep , Kalesh Singh , Linux-MM , Mauro Carvalho Chehab , Michal Hocko , Minchan Kim , mm-commits@vger.kernel.org, Randy Dunlap , Suren Baghdasaryan , Szabolcs Nagy , Al Viro , Michel Lespinasse , Matthew Wilcox Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: E0CF99000094 Authentication-Results: imf29.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=google header.b=cVhJPMc7; spf=pass (imf29.hostedemail.com: domain of torvalds@linuxfoundation.org designates 209.85.167.45 as permitted sender) smtp.mailfrom=torvalds@linuxfoundation.org; dmarc=none X-Stat-Signature: rpmzg4wygj16gpm8iz36adrutudyc8wm X-HE-Tag: 1625271361-346660 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 Fri, Jul 2, 2021 at 4:31 PM Kees Cook wrote: > > Right -- the info leak would be snooping on what a privileged process > was doing with a given fd? Similar stuff has been used to do typing > pattern analysis with login passwords, but that's a stretch here, I > think. Hmm. So I think you'd see the directory list, but generally that's just the file descriptor numbers. Which is information you shouldn't have access to, but it's probably not very *interesting* information. I think it would be worth fixing but possibly not a very high priority. Linus