From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from canpmsgout04.his.huawei.com (canpmsgout04.his.huawei.com [113.46.200.219]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id B9E4E381EB0 for ; Sat, 11 Jul 2026 08:13:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=113.46.200.219 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783757616; cv=none; b=Ts7MG8mW/FEg9ZF29ie0pJZqLBDDNAHMla3BUxt4M62mcvZuVoc4/2mrBto7Ot8czEhcvz8p79UtBTMXIgchGXDN/Phq0kakbA08X30k96SptK/08JtS37TYdz9LF+kTS2/qkUJ9XUYcbFrQM3xJEBL+sSKago1/9wWBvo71gYk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783757616; c=relaxed/simple; bh=RivUc5YUXnOdUgRz0a+Ib/89lZt+K/9x14yXx6ELMXI=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=QeG4imWMaBzvs+BQenKYMCvb5Hc+Ec1Ww0qkY4ovgQoAxVa+3UWvBQQEghzEt0LT2gAJqoL33S+QGGxaY9tbURMakhHtPIWemYL7Db6uzKaVdXtGw0Fv/mrfC8ltXxNP4peNqNwIKpwezm+u6oTTcrwJ1J4HM7+crktXX/NPYcc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com; spf=pass smtp.mailfrom=huawei.com; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b=xw9nzOU5; arc=none smtp.client-ip=113.46.200.219 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=huawei.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=huawei.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=huawei.com header.i=@huawei.com header.b="xw9nzOU5" dkim-signature: v=1; a=rsa-sha256; d=huawei.com; s=dkim; c=relaxed/relaxed; q=dns/txt; h=From; bh=RivUc5YUXnOdUgRz0a+Ib/89lZt+K/9x14yXx6ELMXI=; b=xw9nzOU534pfyhWOzj9pKap8q4607bkkToe3Ipnkb6QWR+MDZTi9e3O/H+gkxG0muwtB62cmy 590BeUAhjDQbde2s0E8aqoxW1fmQ4KWS6jkFNgDjFuif9yo4slxZHN8h5FhDdby0SSxkWEGjE0z aOQke9SiLgZeI4qAHKPdblw= Received: from mail.maildlp.com (unknown [172.19.162.197]) by canpmsgout04.his.huawei.com (SkyGuard) with ESMTPS id 4gy1S444tjz1prLT; Sat, 11 Jul 2026 16:04:04 +0800 (CST) Received: from kwepemj100009.china.huawei.com (unknown [7.202.194.3]) by mail.maildlp.com (Postfix) with ESMTPS id 647634057D; Sat, 11 Jul 2026 16:13:22 +0800 (CST) Received: from DESKTOP-A37P9LK.huawei.com (10.67.109.17) by kwepemj100009.china.huawei.com (7.202.194.3) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.36; Sat, 11 Jul 2026 16:13:21 +0800 From: Xie Yuanbin To: , CC: , , , , , , , , , , , , , , , , Subject: Re: [PATCH v3 1/2] ARM: mm: fix use-after-free in __do_user_fault() under CONFIG_DEBUG_USER Date: Sat, 11 Jul 2026 16:13:03 +0800 Message-ID: <20260711081303.5472-1-xieyuanbin1@huawei.com> X-Mailer: git-send-email 2.53.0 In-Reply-To: References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain X-ClientProxiedBy: kwepems200002.china.huawei.com (7.221.188.68) To kwepemj100009.china.huawei.com (7.202.194.3) On Sat, 11 Jul 2026 09:05:03 +0100, Lorenzo Stoakes wrote: > OK given arm32 can't do any of the stuff that makes kernel faults an issue, and > if it's certain you can't deadlock on mmap write lock for VMA or non-VMA ranges > on user fault, then no need for the mmap write trylock, and just take the mmap > write lock unconditionally for user faults, and no lock for kernel faults I > guess? Yes, that's exactly what I think. We are waiting for ARM's maintainer Russell King to confirm, and then we will send out the new patch. :)