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 A3F7FF45A1C for ; Tue, 14 Apr 2026 05:17:35 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id D7AED6B0088; Tue, 14 Apr 2026 01:17:34 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D2C546B008A; Tue, 14 Apr 2026 01:17:34 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C42B76B0092; Tue, 14 Apr 2026 01:17:34 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0017.hostedemail.com [216.40.44.17]) by kanga.kvack.org (Postfix) with ESMTP id B12716B0088 for ; Tue, 14 Apr 2026 01:17:34 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 632898B81D for ; Tue, 14 Apr 2026 05:17:34 +0000 (UTC) X-FDA: 84656003628.01.C790095 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf02.hostedemail.com (Postfix) with ESMTP id A12F48000B for ; Tue, 14 Apr 2026 05:17:32 +0000 (UTC) Authentication-Results: imf02.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=12sUYr1m; spf=pass (imf02.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1776143852; 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=4zcFpRvfg2gFpsyLn+GB/lXfcqVkmxO1BkkPIVAthpQ=; b=Gq/fD8SsejLh02iYGlKz8WmIZtNOJ5hyHjw29yoHecT1fTOavkABua3NZNpU5k4vfWLLPa /wQQkSR35yGccSrjQdiogMxjQilXuIs8XVyl6hEACOHCB/ma1PFBqf8mhJm7MjY6xLSYAT +nbl27oXbLKlDpzHNMnakTOrWO/9bto= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1776143852; a=rsa-sha256; cv=none; b=p4g6c2huEwsoIuQyJ5f9p1Q51OEdk0BLaMrRGVJD9a3d6C5+/KqB/CMqm2odR2xva9mER/ 0VaJhHTB3TvmEspEFPicSZ+Wpli7X7T8AbbuOx3/CzoYn8K5uX1qZVn3BycdZ75RPb4Wqf czoDaolEt3NuMdAYM2yWqTWDQXRtTjU= ARC-Authentication-Results: i=1; imf02.hostedemail.com; dkim=pass header.d=linux-foundation.org header.s=korg header.b=12sUYr1m; spf=pass (imf02.hostedemail.com: domain of akpm@linux-foundation.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=akpm@linux-foundation.org; dmarc=none Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 8CA4D43DBC; Tue, 14 Apr 2026 05:17:31 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 742AEC19425; Tue, 14 Apr 2026 05:17:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1776143851; bh=82K051Tep/JkEig50wE4zoQmsPmPeGZ44gpDUIO1KyY=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=12sUYr1mFI8KyEGPtwEEyJm/H3SK5yWb3apghtC+Y6KWqtz+TlkuU3OLAq8gtd3nf f0YI29yQdVlArq7MbdKsJaf1aGsJMxxYe+u8ef+22H2bp7RnIhlPWEBcH+8FfuGoGC xn0vqs060EZnSWWKem3d1work+YJmIkWgmePZJ1M= Date: Mon, 13 Apr 2026 22:17:24 -0700 From: Andrew Morton To: Lorenzo Stoakes Cc: Alexander Viro , Christian Brauner , Jan Kara , David Hildenbrand , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Shinichiro Kawasaki Subject: Re: [PATCH mm-hotfixes] mm/vma: remove __vma_check_mmap_hook() Message-Id: <20260413221724.c939e483e83304fb40e3d6da@linux-foundation.org> In-Reply-To: <20260413105713.92625-1-ljs@kernel.org> References: <20260413105713.92625-1-ljs@kernel.org> X-Mailer: Sylpheed 3.7.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: A12F48000B X-Stat-Signature: he1wricf817m6a5rjc6td98fk98wjeh3 X-Rspam-User: X-Rspamd-Server: rspam07 X-HE-Tag: 1776143852-829148 X-HE-Meta: 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 GvwShvTK J7KGdCcBDZNsLRBlHvMIHnddRpGc9G1sywbIK6Q/HBfpBBgEZ2uZOHfYNzweyfiejcIxsSH47YgY3xmfSj1+zsSnrQYJd9Jq0DSkLM8JCKZgsqsZ8/OyrD+8BYYnk5XKmofpN5+Rf4+cJ1lFHjRLTqprfRGZHi3FEw4isPdQF+/cAT/iXbKV8GRldixY6EWPtXIjP11qV5frT/3DVOAbFyclxCglUuMvFeR4s9HO1nPUOuqizd/gJUajX0bW+wqAdb7UmHtYUET6X6/8pWOtF1eN7IC9H2k4TFwLax6/E/e9TANuhKMAZdRIlAtJdRztJABjS Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, 13 Apr 2026 11:57:13 +0100 Lorenzo Stoakes wrote: > Commit c50ca15dd496 ("mm: add vm_ops->mapped hook") introduced > __vma_check_mmap_hook() in order to assert that a driver doesn't > incorrectly implement both an f_op->mmap() and a vm_ops->mapped hook, the > latter of which would not ultimately get invoked. > > However, this did not correctly account for stacked drivers (or drivers > that otherwise use the compatibility layer) which might recursively call > an mmap_prepare hook via the compatibility layer. > > Thus the nested mmap_prepare() invocation might result in a VMA which has > vm_ops->mapped set with an overlaying mmap() hook, causing the > __vma_check_mmap_hook() to fail in vfs_mmap(), wrongly failing the > operation. > > This patch resolves this by simply removing the check, as we can't be > certain that an mmap() hook doesn't at some point invoke the compatibility > layer, and it's not worth trying to track it. Cool, thanks. > Fixes: c50ca15dd496 ("mm: add vm_ops->mapped hook") That's presently in flight mm.git->Linus, So I'll include this fix in next week's second batch of MM updates into Linus. > c50ca15dd496 is in mm-stable, so thought best to do as fix-patch? Will > leave a small bisection hazard (unfortunately) so putting this as close as > possible to the patch it fixes would be ideal. Yep, I did that.