From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from m16.mail.126.com (m16.mail.126.com [117.135.210.6]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7417742AB4; Fri, 23 May 2025 03:47:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=117.135.210.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747972047; cv=none; b=tLDp/8Xuqkei3LL9bqm6aHAmEyju69iBujxSq4Hy7Sn9ZfBqjaf4tg5f/wAgOhALj2GTPil2Z/8T3VQF506S4VEJfol6xV3g9dF6+qfdTep44OaqXMYyDMhHTueMxU6wwwcLlSbYMCR1VuqanDdnsEH4YV1RrrEjsrvBouxp3QQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1747972047; c=relaxed/simple; bh=IkdmFrSh2VwCtODceQe1mvxAb3VAK663r9TayBQV6g0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=nSebJrIt4LuAVCIR5UGpptEworGirFWXRqk3GWTlf5AdTWvdTf7mJZi73pV2+ZDfh1e/i8Q83zVe3XiCiC9E+X8SCbiU6MnV7hgiyNVuqiU/VVJztq0bNO5NSI75pqyaG1YsqwSPLbxNPINqMstY2iLfitlTbKbqvWIWSYNP3sE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com; spf=pass smtp.mailfrom=126.com; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b=j0CqrPB3; arc=none smtp.client-ip=117.135.210.6 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=126.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=126.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=126.com header.i=@126.com header.b="j0CqrPB3" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=126.com; s=s110527; h=Message-ID:Date:MIME-Version:Subject:To:From: Content-Type; bh=BRlhWrT2SoYXDlWZPjcJEikz+rURnIHTSURTtEo/7GI=; b=j0CqrPB3BVJ2NkTWzNNJzTs2suu7ZY2L22yVmswZVziThaQUpJh9t9b4pblpVs IFWdrQZMU8ehbQTkmMo1ChtK6BuZdCzFHAaH3jZEaw+tacAVzITJ4PXLQxo8XlXs /SWybH5CWos2S04jMlGdC2HIdu7xn8Nax3cAAbQiaKIrg= Received: from [172.19.20.199] (unknown []) by gzga-smtp-mtada-g1-2 (Coremail) with SMTP id _____wD3Xyar7y9oVPJEAg--.40133S2; Fri, 23 May 2025 11:46:51 +0800 (CST) Message-ID: <4e408146-7c77-4f6d-90e8-bb311d7ab53d@126.com> Date: Fri, 23 May 2025 11:46:51 +0800 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm/hugetlb: fix kernel NULL pointer dereference when replacing free hugetlb folios To: Muchun Song , Oscar Salvador Cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org, 21cnbao@gmail.com, david@redhat.com, baolin.wang@linux.alibaba.com, liuzixing@hygon.cn References: <1747884137-26685-1-git-send-email-yangge1116@126.com> <644FF836-9DC7-42B4-BACE-C433E637B885@linux.dev> <3B8641A1-5345-44A5-B610-9BCBC980493D@linux.dev> From: Ge Yang In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-CM-TRANSID:_____wD3Xyar7y9oVPJEAg--.40133S2 X-Coremail-Antispam: 1Uf129KBjvdXoWruF1xWrykuFyrZry7Kr18Grg_yoWkGwc_ZF W0vas7Gw4UZFy0kF4DGrn0qF98Kw45ZF1YvFWrWrWUCFyftF95Xr98tr4fZwsrWa1jkF45 tw1Yva93Ar12kjkaLaAFLSUrUUUUjb8apTn2vfkv8UJUUUU8Yxn0WfASr-VFAUDa7-sFnT 9fnUUvcSsGvfC2KfnxnUUI43ZEXa7IU8OJ55UUUUU== X-CM-SenderInfo: 51dqwwjhrrila6rslhhfrp/1tbidRxWG2gv70MMjAAAsP 在 2025/5/23 11:27, Muchun Song 写道: > > >> On May 23, 2025, at 03:32, Oscar Salvador wrote: >> >> On Thu, May 22, 2025 at 08:39:39PM +0800, Muchun Song wrote: >>> But I think we could use "folio_order() > MAX_PAGE_ORDER" to replace the check >>> of hstate_is_gigantic(), right? Then ee could remove the first parameter of hstate >>> from alloc_and_dissolve_hugetlb_folio() and obtain hstate in it. >> >> Yes, I think we can do that. >> So something like the following (compily-tested only) maybe? >> >> From d7199339e905f83b54d22849e8f21f631916ce94 Mon Sep 17 00:00:00 2001 >> From: Oscar Salvador >> Date: Thu, 22 May 2025 19:51:04 +0200 >> Subject: [PATCH] TMP >> >> --- >> mm/hugetlb.c | 38 +++++++++----------------------------- >> 1 file changed, 9 insertions(+), 29 deletions(-) > > Pretty simple. The code LGTM. > > Thanks. Thanks. The implementation of alloc_and_dissolve_hugetlb_folio differs between kernel 6.6 and kernel 6.15. To facilitate backporting, I'm planning to submit another patch based on Oscar Salvador's suggestion.