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[209.85.167.50]) by smtp.gmail.com with ESMTPSA id n23sm332080lji.36.2021.01.20.11.40.06 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 20 Jan 2021 11:40:06 -0800 (PST) Received: by mail-lf1-f50.google.com with SMTP id u25so35738109lfc.2 for ; Wed, 20 Jan 2021 11:40:06 -0800 (PST) X-Received: by 2002:a19:f014:: with SMTP id p20mr4714519lfc.421.1611171605824; Wed, 20 Jan 2021 11:40:05 -0800 (PST) MIME-Version: 1.0 References: <20210116220950.47078-1-timur@kernel.org> <20210118182635.GD2260413@casper.infradead.org> <20210119014725.GH2260413@casper.infradead.org> <202101191135.A78A570@keescook> <29122c86-bfea-2f25-d111-00641cc660ba@kernel.org> In-Reply-To: From: Linus Torvalds Date: Wed, 20 Jan 2021 11:39:49 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH 0/2] introduce DUMP_PREFIX_UNHASHED for hex dumps To: Petr Mladek Cc: Timur Tabi , Kees Cook , Matthew Wilcox , Sergey Senozhatsky , Andrew Morton , Linux Kernel Mailing List , roman.fietze@magna.com, Steven Rostedt , John Ogness , Linux-MM , Akinobu Mita Content-Type: text/plain; charset="UTF-8" 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 Wed, Jan 20, 2021 at 1:19 AM Petr Mladek wrote: > > And we should definitely add Linus into CC when sending v2. > His expected opinion has been mentioned several times in this > thread. It would be better to avoid these speculations > and get his real opinion. IMHO, it is too late to add > him in this long thread. I've seen it, I've just not cared deeply. I suspect the main issue is if you can cause debug dumps as a normal user and find kernel addresses that way, but I'm not sure how much we care. Somebody _actively_ debugging things might need the address, and KASRL etc be damned. I also suspect that everybody has already accepted that KASLR isn't really working locally anyway (due to all the hw leak models with cache and TLB timing), so anybody who can look at kernel messages already probably could figure most of those things out. So as long as the dumping isn't doing something actively stupid, and as long as hex dumping isn't something that is easily triggered, this probably falls under "nobody cares". Linus