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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 0053ECCF9E3 for ; Mon, 10 Nov 2025 17:33:52 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 440BA8E0034; Mon, 10 Nov 2025 12:33:52 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 3F1298E0003; Mon, 10 Nov 2025 12:33:52 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2E0EF8E0034; Mon, 10 Nov 2025 12:33:52 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 183848E0003 for ; Mon, 10 Nov 2025 12:33:52 -0500 (EST) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay10.hostedemail.com (Postfix) with ESMTP id B548BC01F6 for ; Mon, 10 Nov 2025 17:33:51 +0000 (UTC) X-FDA: 84095395062.03.FB02010 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) by imf13.hostedemail.com (Postfix) with ESMTP id DD11320005 for ; Mon, 10 Nov 2025 17:33:48 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=hDu5eaBS; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=pass (policy=none) header.from=infradead.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1762796030; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=ag6LW6hemevws8YrksBMYRPO4jlV1oMVj+5QJ4bp/14=; b=RWd4Up85nJvdp4bueDAXHdsJJOubQ6TpJEVqDuhZ7FtUcScn8VRu3swkMTWmpIXM4beOLb 5KIxjWPbVx518DxGUyjgOSNapSvKRx40bLMV/PcsmYgKImw5ItEQILvtg1Mlv8geHTmx9E pI9KaTLmsZ8j+dNDGc9Uwg8wDbVzlS4= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=infradead.org header.s=casper.20170209 header.b=hDu5eaBS; spf=none (imf13.hostedemail.com: domain of willy@infradead.org has no SPF policy when checking 90.155.50.34) smtp.mailfrom=willy@infradead.org; dmarc=pass (policy=none) header.from=infradead.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1762796030; a=rsa-sha256; cv=none; b=YYcGPnbyxtNQ3o5ndsKWn7r/SO6qpb1oXxqzqRHprkryoIcivlUnuIwdRkg/5X2rwr7sCB BUjdbo2TYxQJD9gQ7hbfIgj/m2wDJ4ZkzEHMzNkbP4vhiEf92C3HigiZYIlWIrUo3S1Kvf lLIitS/YNgNFWo1oxnqeCZ5/spvQa70= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=In-Reply-To:Content-Transfer-Encoding: Content-Type:MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: Sender:Reply-To:Content-ID:Content-Description; bh=ag6LW6hemevws8YrksBMYRPO4jlV1oMVj+5QJ4bp/14=; b=hDu5eaBS1pVnzx5mZNWnb8VpqO VFIdXUQKfLY8jwIzevEr+VfCN/w6HRq94VSeLELvL0tCdMRmTaKp+OoyCquDJ1YKftqgTXnGuXivN e7G1fRZ4akwXOIQlabKzKhURAD4V49v5AvJZjhK7oI11kCGjD6M+HDEdDojgdSauv5/UUlrCYfnMm VAEBeFyDxGQHEYv+LH8xct0W4ckP/Ijd7RaaLXzyI8yN0V8JTcE+DuFgiFbC9Kj8GA4O/wX2rCojR GDrtV0Zx8uqP60OizixU9gPweGirxQv8fXvN0WQKr4ad6yRB5QhoGbajemapDE6BEyY/3ih/ECIDt Ia90NZoA==; Received: from willy by casper.infradead.org with local (Exim 4.98.2 #2 (Red Hat Linux)) id 1vIVla-00000002xxn-1bOm; Mon, 10 Nov 2025 17:33:22 +0000 Date: Mon, 10 Nov 2025 17:33:22 +0000 From: Matthew Wilcox To: Jinchao Wang Cc: Andrew Morton , "Masami Hiramatsu (Google)" , Peter Zijlstra , Randy Dunlap , Marco Elver , Mike Rapoport , Alexander Potapenko , Adrian Hunter , Alexander Shishkin , Alice Ryhl , Andrey Konovalov , Andrey Ryabinin , Andrii Nakryiko , Ard Biesheuvel , Arnaldo Carvalho de Melo , Ben Segall , Bill Wendling , Borislav Petkov , Catalin Marinas , Dave Hansen , David Hildenbrand , David Kaplan , "David S. Miller" , Dietmar Eggemann , Dmitry Vyukov , "H. Peter Anvin" , Ian Rogers , Ingo Molnar , James Clark , Jinjie Ruan , Jiri Olsa , Jonathan Corbet , Juri Lelli , Justin Stitt , kasan-dev@googlegroups.com, Kees Cook , "Liam R. Howlett" , Liang Kan , Linus Walleij , linux-arm-kernel@lists.infradead.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-trace-kernel@vger.kernel.org, llvm@lists.linux.dev, Lorenzo Stoakes , Mark Rutland , Masahiro Yamada , Mathieu Desnoyers , Mel Gorman , Michal Hocko , Miguel Ojeda , Nam Cao , Namhyung Kim , Nathan Chancellor , Naveen N Rao , Nick Desaulniers , Rong Xu , Sami Tolvanen , Steven Rostedt , Suren Baghdasaryan , Thomas Gleixner , Thomas =?iso-8859-1?Q?Wei=DFschuh?= , Valentin Schneider , Vincent Guittot , Vincenzo Frascino , Vlastimil Babka , Will Deacon , workflows@vger.kernel.org, x86@kernel.org Subject: Re: [PATCH v8 00/27] mm/ksw: Introduce KStackWatch debugging tool Message-ID: References: <20251110163634.3686676-1-wangjinchao600@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20251110163634.3686676-1-wangjinchao600@gmail.com> X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: DD11320005 X-Stat-Signature: zch1rq4s8ebb7h8akcz7uwgsp55ny45n X-Rspam-User: X-HE-Tag: 1762796028-156864 X-HE-Meta: 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 +EgevBrC /K9VcDPJ3dougoWYvOiRFr7fZ4c5xBchgErbvuUVmy1/UAsxVFAom99lD+pdc9MrrXzeD7AMtXEsiBa1Ywx9IK4BvI+SQ1zoZ77JzB5EPCsmbvps07vrUjm9HfPkB89Rg8GX0ZkicEN5/H+Hh19+Y6BzsfkLILAe9+OrqkD7Obcmem2A8mLA7P4Zy/uXXx7EFYa02/pK8jv/qnDYZ8VV6h8o0baqLHZMAGdVKrJ9eYAUB356naVszlLWpX+rNyNk4dlJKQSRke/Yv0G7h/MFDxGiEM3XmtORm37UuELBbQzsJm397Nn35Y5hewPBtXgMF3T7lpWjiHNk3MKmhtCkwyINApQX/RgkghHDy 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 Tue, Nov 11, 2025 at 12:35:55AM +0800, Jinchao Wang wrote: > Earlier this year, I debugged a stack corruption panic that revealed the > limitations of existing debugging tools. The bug persisted for 739 days > before being fixed (CVE-2025-22036), and my reproduction scenario > differed from the CVE report—highlighting how unpredictably these bugs > manifest. Well, this demonstrates the dangers of keeping this problem siloed within your own exfat group. The fix made in 1bb7ff4204b6 is wrong! It was fixed properly in 7375f22495e7 which lists its Fixes: as Linux-2.6.12-rc2, but that's simply the beginning of git history. It's actually been there since v2.4.6.4 where it's documented as simply: - some subtle fs/buffer.c race conditions (Andrew Morton, me) As far as I can tell the changes made in 1bb7ff4204b6 should be reverted. > Initially, I enabled KASAN, but the bug did not reproduce. Reviewing the > code in __blk_flush_plug(), I found it difficult to trace all logic > paths due to indirect function calls through function pointers. So why is the solution here not simply to fix KASAN instead of this giant patch series?