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smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=B6zqLY51; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 95896606A31C for ; Fri, 30 Oct 2026 14:42:28 +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=B6zqLY51 Received: by smtp.kernel.org (Postfix) with ESMTPSA id C0A3A1F000C1; Fri, 30 Oct 2026 14:42:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793371348; bh=OU3zDVKepXMBwwR1kv5zeSUQ4EZ22iKhEWe2jjy3QKQ=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=B6zqLY51HL03HAbN7lCtJ3lFh7DfqAs+MNDqt4pDlmekKLANxMB0eErrw8PsTrl/J bhk9I9VG57rWGojcbjPYDvfXOZwhTgar1YEV5quKfL1b0Pwe/drjQd34EpBd3Y815W 1d9Q5G2Cd5PIPAL+eTV/ecP9RuZBDZ7nl5Bl3mFrSUhrXD4jFsLHyYyYQHsTylLkGn NlinJiDxut9+mjHqjAAEc2p/loJkudu7r+TscY+B+okD70yxrGultokQdRtQ0P+G3n 9sfhmK4CrBl/FEGq+tDpEnsQ7/pUWjxBP13v0uhwQR2Gi+eXMrx0jHd1x30BELyFhY i4QHMyc1GAT4g== Message-ID: <40eadc1b-5057-4286-9be2-021cb16bc020@kernel.org> Date: Fri, 30 Oct 2026 15:42:21 +0100 X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/memory-failure: fix folio refcount leak and min_order_for_split() locking To: Tal Zussman Cc: akpm@linux-foundation.org, ljs@kernel.org, ziy@nvidia.com, baolin.wang@linux.alibaba.com, liam@infradead.org, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, baohua@kernel.org, lance.yang@linux.dev, usama.arif@linux.dev, linmiaohe@huawei.com, nao.horiguchi@gmail.com, richard.weiyang@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, mcgrof@kernel.org, liyouhong@kylinos.cn References: <20260806-try_to_split_thp_page-v1-1-a259e3387e38@kernel.org> <20261030105022.903008-1-tz2294@columbia.edu> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 10/30/26 11:50, Tal Zussman wrote: > On Thu, Aug 06, 2026 at 01:14:38PM +0200, David Hildenbrand (Arm) wrote: >> hwpoison code can end up calling min_order_for_split() without holding >> the folio lock. There isn't really something that would prevent >> concurrent folio split. Consequently folio->mapping can get set to >> NULL after checking for "!folio->mapping", and if the compiler >> reloads folio->mapping, mapping_min_folio_order() would try to >> dereference NULL. > > Hi David, > > Did this patch ever make it in? If you ask this way ... I guess not? :D I can see if it still applies and resend + apply. -- Cheers, David