From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E3B83D116EA for ; Sat, 29 Nov 2025 02:18:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type: Content-Transfer-Encoding:MIME-Version:References:In-Reply-To:Message-ID:Date :Subject:CC:To:From:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=kn01DPqEWVsRKnyDlfL02PwCBxz8cu2USXRLYTQgCgM=; b=qVrv2tWK8jfK9PYYe/sIdjg9Th WpBZoroNb9lfqaSW3ckF5QNa2WSmOrgXGW2Q4Nw9NWPn3Z6xhJ1HfrmRKO1TeN7sIknY2oqDYrKgK 723gT5S+Sg6wnMuXp4GE4ZrwABfof66dDQhjqqSlk8ubPxyZnw1ds23m8Y/29KMnSpJ/H3qhPc/1v sgMBZNE06iA3mrxl1IHdxgMln5mSy9sq7ymdAoENvWJ7EAhNEzxSSIN+7gl2lza0c1xiN274+aw87 9meeOc5c7ap3Vcnj5qP2w0ZaDEIvizt99xfky/7PM2ukc3/TdXkyrAMCsaMflonRskXC8xKHdwYED Z/sboarw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vPAXl-00000001AZe-1qM4; Sat, 29 Nov 2025 02:18:37 +0000 Received: from canpmsgout01.his.huawei.com ([113.46.200.216]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vPAXh-00000001AYs-3HMh for linux-arm-kernel@lists.infradead.org; Sat, 29 Nov 2025 02:18:35 +0000 dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=kn01DPqEWVsRKnyDlfL02PwCBxz8cu2USXRLYTQgCgM=; b=rDScHZVCx+yxOePYn8Wcv7pT5EneAyhEXpKgyfyNlZdFO+SZjIfif2JCM3YYpKX2AogeDsnam /17hK+QDSVVTcvAMpeNH1ZD5mzB3UTmEMrJEwauBJgQWVmdxVILASAgXYxRyzaIgfUZb+JMrv57 oTVqNBOiz4Z5xvjvvJvwaQw= Received: from mail.maildlp.com (unknown [172.19.163.252]) by canpmsgout01.his.huawei.com (SkyGuard) with ESMTPS id 4dJDLT42p1z1T4Fk; 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-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251128_181834_310491_0377B35D X-CRM114-Status: GOOD ( 12.62 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org 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