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Sat, 29 Nov 2025 10:16:33 +0800 (CST) Received: from kwepemj100009.china.huawei.com (unknown [7.202.194.3]) by mail.maildlp.com (Postfix) with ESMTPS id 18451180B58; Sat, 29 Nov 2025 10:18:20 +0800 (CST) Received: from DESKTOP-A37P9LK.huawei.com (10.67.109.17) by kwepemj100009.china.huawei.com (7.202.194.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Sat, 29 Nov 2025 10:18:19 +0800 From: Xie Yuanbin To: , , , , , CC: , , , , , , , , , , , , , , , Subject: Re: [Bug report] hash_name() may cross page boundary and trigger Date: Sat, 29 Nov 2025 10:18:15 +0800 Message-ID: <20251129021815.9679-1-xieyuanbin1@huawei.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: References: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-Originating-IP: [10.67.109.17] X-ClientProxiedBy: kwepems100001.china.huawei.com (7.221.188.238) To kwepemj100009.china.huawei.com (7.202.194.3) X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 0062240012 X-Stat-Signature: zyx44pimpt1s97347mgzhozi99qebu6x X-HE-Tag: 1764382704-527059 X-HE-Meta: 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 4GQX9x+o ZfdgXGT2911zc7rlVRoKve9ABW9+fzXBllaGs/gLi5G4X48E2HJUMNVLuAk3fKdTAACvuHBxhbpleg/DMSW11D2LFsX3JVzUiefQWKpLBA8rIze43tg/X7XB4swPwqmnszYL+qcnj+UAQ53PrP5efMYJUJB+32426CTkDWLiRVMkiWfUnjcCb1cHbH7VQLui2/k6WuC48Tj9dh87Oz7vMdMxxr8RL6lMxAHzLVKaJYGWHNA8WAC2sYDGw004/gAlHWzzUaehKykmECt8ETqMdeEvLcE8yzFwN/fpBI0BgDbdmrgzghoNvijA3ej0zhgnuLduuw0hBgTjHtgClELkxa/W3wTTLI240ql/pym97Yf/7WHS4tqpkYpnHwi0oF97gYtxgwRxsqdWdZxBVqig5R0y3mO3onBB6vYUzkMipV12BSuDghvql8EYK5N4iDeTzNUKsj38Cbxh/U7ZmFa0JG/IroA== 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: Hi, Linus Torvalds and Will Deacon! We have some discussion and solutions on other threads, and it seems that there are somthing missing on this discussion thread. Therefore, I think it is necessary to synchronize some information here. 1. There is a test case that can consistently reproduce the bug, which might be helpful for us to do the test. The test case is located after the '---' maker line in the following patch: Link: https://lore.kernel.org/20251126101952.174467-1-xieyuanbin1@huawei.com 2. Al Viro give a suggest on 2025-11-26 19:26: Link: https://lore.kernel.org/20251126192640.GD3538@ZenIV This patch is similar to one I submitted long time ago, which was intended fix another bug: missing branch predictor mitigation: Link: https://lore.kernel.org/20250925025744.6807-1-xieyuanbin1@huawei.com My patch was not accepted, Sebastian's patch: Link: https://lore.kernel.org/20251110145555.2555055-2-bigeasy@linutronix.de fixed this bug, but Sebastian's patch has not yet been merged into the linux-next branch, so this bug still exists in the current linux-next branch. I hope there is a simple solution to fix both bugs, so I submitted this patch on 2025-11-27 14:49: Link: https://lore.kernel.org/20251127140109.191657-1-xieyuanbin1@huawei.com This patch is based on the linux-next branch, therefore it does not contain Sebastian's patch. 3. On 2025-11-28 17:06, Linus Torvalds provided a solution similar to Al Viro's suggestion and my patch: Link: https://lore.kernel.org/CAHk-=wh+cFLLi2x6u61pvL07phSyHPVBTo9Lac2uuqK4eRG_=w@mail.gmail.com Currently, all solutions have been tested that can fix this one bug. I still hold the view that perhaps there is a simpler way to fix another bug at the same time, because the solutions of these two bugs are very similar. Thanks very much! Xie Yuanbin