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 B2394D116F3 for ; Wed, 3 Dec 2025 07:30:24 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 9754C6B000E; Wed, 3 Dec 2025 02:30:23 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 926176B0010; Wed, 3 Dec 2025 02:30:23 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 83BF16B0011; Wed, 3 Dec 2025 02:30:23 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 740656B000E for ; Wed, 3 Dec 2025 02:30:23 -0500 (EST) Received: from smtpin09.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay08.hostedemail.com (Postfix) with ESMTP id A119B1403F5 for ; Wed, 3 Dec 2025 07:30:20 +0000 (UTC) X-FDA: 84177336600.09.E32FD59 Received: from mail-24416.protonmail.ch (mail-24416.protonmail.ch [109.224.244.16]) by imf30.hostedemail.com (Postfix) with ESMTP id CC6F080002 for ; Wed, 3 Dec 2025 07:30:18 +0000 (UTC) Authentication-Results: imf30.hostedemail.com; dkim=pass header.d=pm.me header.s=protonmail3 header.b=OOAew4S9; spf=pass (imf30.hostedemail.com: domain of m.wieczorretman@pm.me designates 109.224.244.16 as permitted sender) smtp.mailfrom=m.wieczorretman@pm.me; dmarc=pass (policy=quarantine) header.from=pm.me ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1764747019; 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: references:dkim-signature; bh=CDRU707d2INpmwpTAfBR2VrUuDWM3CQSFKF4zJkZLpc=; b=AUgcbcK23E+SzAiJGtAXzshzaVmZzdGPMS5TonDp75M+/XXCARUClqtL/PvzTlqq7IB7gT rF8TMHS3Vgi4z5nx/QJN164e7C0VYaI0WR25LFGRF41W/FxSdbl3MMaiKB85rXV9ERcbuX pQILZkQmP7DBgIlNPingUcFLBSJhoa0= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1764747019; a=rsa-sha256; cv=none; b=FZD5Z65Uz3xMhOVM6DdlVfS5ebawvurg4k59MA2UMxTJWANWzCwWTN+p1w1vWs67MfLNtl WWi2GVLifIIFb05zodPjWzgS2aN2MgHtYtWhYJwG4cIET4xM1FnROdtOcOy8SIzyf3rPhX xkNGLNwXoZdZiZoZoZwVju2ojWDIadU= ARC-Authentication-Results: i=1; imf30.hostedemail.com; dkim=pass header.d=pm.me header.s=protonmail3 header.b=OOAew4S9; spf=pass (imf30.hostedemail.com: domain of m.wieczorretman@pm.me designates 109.224.244.16 as permitted sender) smtp.mailfrom=m.wieczorretman@pm.me; dmarc=pass (policy=quarantine) header.from=pm.me DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=pm.me; s=protonmail3; t=1764747016; x=1765006216; bh=CDRU707d2INpmwpTAfBR2VrUuDWM3CQSFKF4zJkZLpc=; h=Date:To:From:Cc:Subject:Message-ID:Feedback-ID:From:To:Cc:Date: Subject:Reply-To:Feedback-ID:Message-ID:BIMI-Selector; b=OOAew4S9QEHV8Cdmz22rEdkYi6SFNVv93POgRaL6Xe8I3qWoNThzBhj2VGF+PzAtj h383Dv2Zp0lnXpfCoZRGvAArwv+8JCkFemWkbq6yWDlm7KSnhG6h/DFxCARKJmBAuX qdV1V9sx5Bz+DF5UYeANcnxuM0p10lmqkKNRmj0r4o0a0EGUsShuBne3nR+zwhjv9j 1H/96A27lFI5H/k+KZvF9yfKzB6MLZ6qXaHl7OaDCzp3zHUEJk6/+nrN1FIRXoIqTV dVdJA1vv1hUs73U69CaY4RRGY7MlpyFGIu4iS6HWAOmDHko9yUzGvaxDKmztJ/wAiT MpRbBJZP7ld1w== Date: Wed, 03 Dec 2025 07:30:10 +0000 To: Jiayuan Chen From: =?utf-8?Q?Maciej_Wiecz=C3=B3r-Retman?= Cc: Maciej Wieczor-Retman , linux-mm@kvack.org, syzbot+997752115a851cb0cf36@syzkaller.appspotmail.com, Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , Uladzislau Rezki , Danilo Krummrich , Kees Cook , kasan-dev@googlegroups.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] mm/kasan: Fix incorrect unpoisoning in vrealloc for KASAN Message-ID: Feedback-ID: 164464600:user:proton X-Pm-Message-ID: 4c6696efba181766eb8a1fc4beeaf0a6b1777034 MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Rspamd-Server: rspam08 X-Rspamd-Queue-Id: CC6F080002 X-Stat-Signature: uy86f9rzx54deahrky4xca19hhogo4ya X-Rspam-User: X-HE-Tag: 1764747018-412296 X-HE-Meta: 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 xEYs4v9f XPSUYvYnAxn45jAXZiou+iQx9kkpfvRIu9I0q44rfVYTWR22U9M+Fl/8jq/e3yyrR5kcsv2BTujCn/WOTw7BWjfRVSBCdYXzkeEILi07m5VW6TbFYWPv3Hgy9bPKTGc/YxRO2BENvDMtNqpCYJdsIOiDGqCfy6A7OPrC6PFocj3iEueTVDlEs+sp/Oy9+6O4v70+Yq3h7wrrELt4o++3TFKfrVu7gMQWtJGB3fYDrio9w3jX6DKvmzUxqwpXhi0DLJ8Ejjt4fpUPy6sb6RLccR39Cjiee8x9KFT6tdR4Yk0gaar3arv/d/e+aCZnqKhowOiA2JCJMBOIb/FaktKgyHczC9lOhN09aIlTqqfeXE5e9O2BMMU/CWSSaqus8KfUtnU/pfw6GO2SabPBOEha5VAN2xp3phyS1eaVm 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 2025-12-03 at 02:05:11 +0000, Jiayuan Chen wrote: >December 3, 2025 at 04:48, "Maciej Wieczor-Retman" >mailto:maciej.wieczor-retman@intel.com?to=3D%22Maciej%20Wieczor-Retman%22%= 20%3Cmaciej.wieczor-retman%40intel.com%3E >> wrote: >>=20 >> Hi, I'm working on [1]. As Andrew pointed out to me the patches are quit= e >> similar. I was wondering if you mind if the reuse_tag was an actual tag = value? >> Instead of just bool toggling the usage of kasan_random_tag()? >>=20 >> I tested the problem I'm seeing, with your patch and the tags end up bei= ng reset. >> That's because the vms[area] pointers that I want to unpoison don't have= a tag >> set, but generating a different random tag for each vms[] pointer crashe= s the >> kernel down the line. So __kasan_unpoison_vmalloc() needs to be called o= n each >> one but with the same tag. >>=20 >> Arguably I noticed my series also just resets the tags right now, but I'= m >> working to correct it at the moment. I can send a fixed version tomorrow= . Just >> wanted to ask if having __kasan_unpoison_vmalloc() set an actual predefi= ned tag >> is a problem from your point of view? >>=20 >> [1] https://lore.kernel.org/all/cover.1764685296.git.m.wieczorretman@pm.= me/ >>=20 > > >Hi Maciej, > >It seems we're focusing on different issues, but feel free to reuse or mod= ify the 'reuse_tag'. >It's intended to preserve the tag in one 'vma'. > >I'd also be happy to help reproduce and test your changes to ensure the is= sue I encountered >isn't regressed once you send a patch based on mine.=20 > >Thanks. Yes, the final issues are different, just we both want to use __kasan_unpoison_vmalloc slightly differently. Okay, then I'll rebase my patches onto your patch, restest on my end and resubmit my series. I'll add you to CC and reply in this thread too. Thanks :) kind regards Maciej Wiecz=C3=B3r-Retman