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[209.85.208.52]) by smtp.gmail.com with ESMTPSA id 4fb4d7f45d1cf-5d097e8db19sm3175263a12.61.2024.11.30.13.33.21 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 30 Nov 2024 13:33:23 -0800 (PST) Received: by mail-ed1-f52.google.com with SMTP id 4fb4d7f45d1cf-5d071f70b51so3875982a12.3 for ; Sat, 30 Nov 2024 13:33:21 -0800 (PST) X-Forwarded-Encrypted: i=1; AJvYcCUaaoby9KjsBguF8TbsebHTPOFzjPNaxTiI6Pf50WXdOCCUWxtcYi5Wg1FfnJyHOxZ9enkI79r/sQ==@kvack.org X-Received: by 2002:a17:906:3090:b0:aa5:1585:ef33 with SMTP id a640c23a62f3a-aa580f1ae0emr1355585766b.23.1733002401515; Sat, 30 Nov 2024 13:33:21 -0800 (PST) MIME-Version: 1.0 References: <20241130044909.work.541-kees@kernel.org> <202411301244.381F2B8D17@keescook> In-Reply-To: <202411301244.381F2B8D17@keescook> From: Linus Torvalds Date: Sat, 30 Nov 2024 13:33:05 -0800 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [PATCH] exec: Make sure task->comm is always NUL-terminated To: Kees Cook Cc: Eric Biederman , Alexander Viro , Christian Brauner , Jan Kara , linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Valentin Schneider , Jens Axboe , Pavel Begunkov , Andrew Morton , Chen Yu , Shuah Khan , =?UTF-8?B?TWlja2HDq2wgU2FsYcO8bg==?= , linux-kernel@vger.kernel.org, io-uring@vger.kernel.org, linux-hardening@vger.kernel.org Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: 24D1AC0007 X-Stat-Signature: yqr69eokjs7z8r9cjhi84g8rtyj34ixh X-Rspam-User: X-HE-Tag: 1733002392-781807 X-HE-Meta: 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 djEaPDc1 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 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: List-Subscribe: List-Unsubscribe: On Sat, 30 Nov 2024 at 13:05, Kees Cook wrote: > > Yeah, this just means it has greater potential to be garbled. Garbled is fine. Id' just rather it be "consistently padded". > This is fine, but it doesn't solve either an unstable source nor > concurrent writers to dest. Yeah, I guess concurrent writers will also cause possibly inconsistent padding. Maybe we just don't care. As long as it's NUL-terminated, it's a string. If somebody is messing with the kernel, they get to the garbled string parts. Linus