From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.subspace.kernel.org (Postfix) with ESMTP id D0E1560A3803 for ; Thu, 29 Oct 2026 13:53:49 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=M3HmIYHz Received: by kanga.kvack.org (Postfix) id F0B1C6B05B4; Thu, 29 Oct 2026 09:53:48 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id EBB3D6B05B5; Thu, 29 Oct 2026 09:53:48 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id DD1666B05B6; Thu, 29 Oct 2026 09:53:48 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0016.hostedemail.com [216.40.44.16]) by kanga.kvack.org (Postfix) with ESMTP id BB1616B05B4 for ; Thu, 29 Oct 2026 09:53:48 -0400 (EDT) Received: from smtpin27.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 4C137A7DE0 for ; Thu, 29 Oct 2026 13:53:48 +0000 (UTC) X-FDA: 85375806936.27.789510C Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf27.hostedemail.com (Postfix) with ESMTP id 9A99040004 for ; Thu, 29 Oct 2026 13:53:46 +0000 (UTC) Authentication-Results: imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=M3HmIYHz; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of harry@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=harry@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793282026; 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=Gdoc5Am/YBseDTfgXtnisv+FjHXqKxuoLVpJqBPFPlY=; b=KmEeZJVfyOC6P45E1b6G5hK2C17EgUxcK7OB1O3IHCt6GTAmrT7wyp7UnJ/S8s/DNjILF8 ao/BlBEO4cDURW1wpT+dOJz8iIz3Go0RVlHNXjhD1ysbeYuxttuwJ0Xt7S67J8bJyyBlzP ViSDABWOdrnU6pON2/XvRIhCk6lnDRE= ARC-Authentication-Results: i=1; imf27.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=M3HmIYHz; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf27.hostedemail.com: domain of harry@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=harry@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793282026; b=e9LuCeTMREuPPVcLKNu1R8++TklCG6Is993vLm6qQtF3ieIWPwaiWDQBRln6m4g9kdVvrF pHHABUqTlvL1Rt+/hqfBhM3ddBiGAdpqtUaZhT4MZtXWlz2xELHnYfe5BwyRMGRv54Kktr LAivXJYr8paKpRvrls+f+uDfB6Lc9zk= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 0EA53419EF; Thu, 29 Oct 2026 13:53:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 73C0F1F01289; Thu, 29 Oct 2026 13:53:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793282024; bh=Gdoc5Am/YBseDTfgXtnisv+FjHXqKxuoLVpJqBPFPlY=; h=Date:From:To:Cc:Subject:References:In-Reply-To; b=M3HmIYHzgzrq+TvNMzkOQTAXJE8pF0/vOG4TWaWU6vznIeQRSriDYGhVgG0Ld/gzs 72Tp0PQptXez1UqZd9OIbFk3upGQQiu0keBCw1F97l/Ip11nlzeBfnTZgqZ9iMupr4 XAqQ8Xa13nDepTBqVlIppdsYVL7zMuf1sPVSBX9hyAQzLaU0IVLAyYmSBafKAqYoEj myQdEZEuQs0hoF/5y3r7l/NnPw4hYji9CZdtnmfpMDPJhH2TrKGV6NZgQqjN9ZMK/K scCfEkkWjPDgjMFczUajKWefVIrs1Rcb6S9ZCsDA4Qy1r/gtx6iBfDsBsEKT3MrLzr oFswdeO4Mpviw== Date: Thu, 29 Oct 2026 13:53:42 +0000 From: Harry Yoo To: Kuniyuki Iwashima Cc: Andrew Morton , Andrey Ryabinin , Vlastimil Babka , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Hao Li , Christoph Lameter , David Rientjes , Roman Gushchin , kasan-dev@googlegroups.com, linux-mm@kvack.org Subject: Re: [PATCH v3 2/2] mm/kasan/kunit: Add double-free tests involving kfree_rcu_sheaf(). Message-ID: References: <20261028194014.3671161-1-kuniyu@google.com> <20261028194014.3671161-3-kuniyu@google.com> <20261028214628.aaaa47c78c5b1257d399257c@linux-foundation.org> X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: X-Rspamd-Queue-Id: 9A99040004 X-Stat-Signature: e8d85o8u9gfpyhj3admg6yyt5duf6y3m X-Rspamd-Server: rspam04 X-Spam-Status: No, score=-10.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,MAILING_LIST_MULTI,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Rspam-User: X-HE-Tag: 1793282026-804286 X-HE-Meta: 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 1AZ9h1mI 94NGTftAdf/QTSg9VtbiIlm/mGPrU+3fqzjKpPX1R4d226W9ZZs++jtfT68nReukqMx66pUAU01pXEVEntqDb2l6A7oc5UAQQnFsQpgfkYKn3mCaYXrLjJ2Ya4Wy/YokyKG0Lw5ltNaPjFhk/8tlEjIikyQ6FnXMporMTdEsc7fTInyY8eesYxeT4BlgknAEXCzI5yf9aKUuhp06g94UYvirb2VC8S3Fg94VllU9VluxGNhCLzkaeTEWjPKJR3OOIuY9s6454PURnSBymBsf7U5SwO9/P+MZHQ+u8+i5I67gk7I4qxHZ8Pd4+awuQuJgL5uxyZvm5FQgJ8h+x7XytEs/ppLUyL+pJb25Z/dwnPrHRbxUN6uZsbsJBGfod0P/yZ4yOIXoom2/TXijXaO98VGSFWJI35DNL53u89LEPW+/CfT/PNuGFphbvERGy1Lv2kaPeFi8p3WCER/gb6+V6+X5YRVo2B3bt9atFo6frj5Tww0U= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 On Wed, Oct 28, 2026 at 09:51:59PM -0700, Kuniyuki Iwashima wrote: > On Wed, Oct 28, 2026 at 9:46 PM Andrew Morton wrote: > > > > On Wed, 28 Oct 2026 19:39:20 +0000 Kuniyuki Iwashima wrote: > > > > > The new test cases verify that KASAN immediately detects all > > > three combinations of double-free involving kfree_rcu_sheaf(): > > > > > > 1. kmem_cache_free() -> kfree_rcu() > > > 2. kfree_rcu() -> kmem_cache_free() > > > 3. kfree_rcu() -> kfree_rcu() > > > > > > Each test also evicts the object from the KASAN quarantine and > > > reallocates it as a victim object before flushing the RCU sheaf > > > to ensure the live victim object is not poisoned by the rejected > > > double-free. > > > > > > Without the patch, all tests fail to detect the 2nd free, and > > > the victim is poisoned: > > > > > > ... > > > > > > With the patch, all tests can detect the 2nd free immediately and > > > prevent the victim from being poisoned: > > > > > > Signed-off-by: Kuniyuki Iwashima > > > Reviewed-by: Alexander Potapenko > > > > Thanks. I believe this should have > > > > Fixes: ec66e0d59952 ("slab: add sheaf support for batching kfree_rcu() operations") Looks correct to me. > > and that both patches deserve a cc:stable. Please comfirm. At least KASAN parts deserve it assuming people use KASAN for testing and fuzzing. > I was not sure if a new KUnit test deserved it, but I have no > strong opinion, and I'm fine with that. -- Cheers, Harry / Hyeonggon