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b=Z2yl4AG+DDuiNKAIq00L1ydlT+ob+tHWu6IoW8eaCQNKBU446v5PU5RoTdVkL7pK7 BCsXha16oPM4GNQghIHtRxWSYIPW+rCKuVWArSy1vJLUCq15l7JaeG63krPAp19JU8 A1ukokpCAVnGgGymDNhBIgDBUz1vb0wkH64MXvTp4R3gFwpJOHewtjyh+qhIcX3zEf 3QbhoUH+5uk9ADUrqlOh7kADfeoDvYK+Ve+9OSoVh8mq8HCmz5HYUAx5Ny8SLADEox FU87babFFzF9nLmkQ+1Zik1QI2vjMDN6CrHQOk3Tza0sNj/qPwvcSr8Oxp2NRKPJSO TMnjxC/5R6Nlg== From: SeongJae Park To: Joshua Hahn Cc: SeongJae Park , Andrew Morton , Vlastimil Babka , Jonathan Corbet , Mike Rapoport , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, kernel-team@meta.com Subject: Re: [PATCH v2 1/2] mm/mm_init: Introduce a boot parameter for check_pages Date: Mon, 24 Nov 2025 17:10:57 -0800 Message-ID: <20251125011058.74734-1-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20251124225408.2243564-1-joshua.hahnjy@gmail.com> References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 88C6220006 X-Stat-Signature: ae58dkxgqqc8xcb71mqia3g9idb7ije5 X-Rspam-User: X-HE-Tag: 1764033067-196141 X-HE-Meta: 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 If1c3tyi gO0QWR4vvtqz/IKpYcklO33I4kGfq9Qc5OTG30aG4aMndpvEnSwNe6cyce4Ujvur89ExQnpnRu3+um8pWO2jQ3+vy64dU7sCsDDcaGj7TgQAutAIIrXJlqJmYf0heE1XHL0dkNFePFFgsjYBZs7SoYe3Z5TYEuN53pbNNSw5Ygje1l0gveXiJB5mRoiGzdJjd0PvtDT3oZRdQOFY9bE+NLEqMr9bmFpvkefjpJePJZdtAOjGuum68NtH7es//BqiZ1SBo3QY2R8KIcBavbL/V2R1AFnDywlC+4g5n55pwdfYToXuOShDGZHqx3dAcOg2pnMoQvKAudbyDs7A= 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 Mon, 24 Nov 2025 14:54:06 -0800 Joshua Hahn wrote: > Use-after-free and double-free bugs can be very difficult to track down. > The kernel is good at tracking these and preventing bad pages from being > used/created through simple checks gated behind "check_pages_enabled". > > Currently, the only ways to enable this flag is by building with > CONFIG_DEBUG_VM, or as a side effect of other checks such as > init_on_{alloc, free}, page_poisoning, or debug_pagealloc among others. > These solutions are powerful, but may often be too coarse in balancing > the performance vs. safety that a user may want, particularly in > latency-sensitive production environments. > > Introduce a new boot parameter "check_pages", which enables page checking > with no other side effects. It takes kstrbool-able inputs as an argument > (i.e. 0/1, true/false, on/off, ...). This patch is backwards-compatible; > setting CONFIG_DEBUG_VM still enables page checking. > > Signed-off-by: Joshua Hahn Acked-by: SeongJae Park Thanks, SJ [...]