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 4659C606A325 for ; Mon, 26 Oct 2026 23:26:43 +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=NqxXcyZ5 Received: by kanga.kvack.org (Postfix) id 6CB1E6B05E5; Mon, 26 Oct 2026 19:26:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 6A21B6B05E6; Mon, 26 Oct 2026 19:26:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 5B7566B05E7; Mon, 26 Oct 2026 19:26:42 -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 EF8FD6B05E5 for ; Mon, 26 Oct 2026 19:26:41 -0400 (EDT) Received: from smtpin06.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay09.hostedemail.com (Postfix) with ESMTP id 969048031C for ; Mon, 26 Oct 2026 23:26:41 +0000 (UTC) X-FDA: 85366364202.06.859CEAE Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf11.hostedemail.com (Postfix) with ESMTP id C0A7440005 for ; Mon, 26 Oct 2026 23:26:39 +0000 (UTC) Authentication-Results: imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=NqxXcyZ5; spf=pass (imf11.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793057199; 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=JD3h3UamRh59QcjyL8J1MuE/w/u1X5RZ3DOsE1wllXg=; b=qsrK1eD+UIhBbvTqxoZY17GXf3xLPXOW2jRLIW+wLw6/0GmaRiX+3WWSGHC2PDaAOYD7OQ WqnGcrT2pYw4VWc/Bdip1eIICicx93xaLZ+PylJaPBei3+WoDfCxBEJL4/MIcij5p0iBSk seZHXfF+gVAU+o0z1JTR5eAQtZvbtOs= ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793057199; b=iz9Zx2ZAEso8NGYcpwFZQUpQYumWu5grb/4mpQZNyHcS4NUpmRHhRB3oFSCMI6nOe6q/i+ B0PnTVjEZM0xAt6zrv+V51jl0uTkzm/+0WypeusLX4GEDZzUa0rK3lygtaJXaPe31lCE+k UtLvgAB6+EsC5yghbctwahKY9dfLTZA= ARC-Authentication-Results: i=1; imf11.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=NqxXcyZ5; spf=pass (imf11.hostedemail.com: domain of david@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=david@kernel.org; dmarc=pass (policy=quarantine) header.from=kernel.org Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 19E2F411CF; Mon, 26 Oct 2026 23:26:39 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 06A8C1F01825; Mon, 26 Oct 2026 23:26:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793057199; bh=JD3h3UamRh59QcjyL8J1MuE/w/u1X5RZ3DOsE1wllXg=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=NqxXcyZ5B7hNxVICB8D7ZuTu2KTFj1aY/wZHjWEHcrphKUZXEhErMydzk2Pzo1mLO KXsakbOlKadHDvCpmoPg4VdpWYop82udMmVVbnJSsa/yNZfnIpnc7zXVJuFxKNqzsX XXtyntURfV0Gyys700YmRUpcZNsNBwSVXZSPdu5SAf1AyhwNb3x1lfgitOWD3HGdQS vWS7Cl3Pan8Rn7XnMFij0eGv/K6IbU4S0Jzeq3EhdCV3hZuhxaFbAcpEYOR+STaAHN NiDWgUxmVXVvm5yitg/azM9C5yVHptICOOnN2qnAup6cV1VLBTsoFalfWOvsoe9Zzc roonF+qboPgYw== From: "David Hildenbrand (Arm)" Date: Tue, 27 Oct 2026 00:17:48 +0100 Subject: [PATCH 28/46] mm/mmu_notifier: set ->mm only after mmgrab() X-Archived-By: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20261027-fixes_core-v1-28-6f74bec9a5bb@kernel.org> References: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> In-Reply-To: <20261027-fixes_core-v1-0-6f74bec9a5bb@kernel.org> To: Andrew Morton , Johannes Weiner , Michal Hocko , Qi Zheng , Shakeel Butt , Lorenzo Stoakes , Kairui Song , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Baoquan He , Baolin Wang , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Kees Cook , Peter Zijlstra , Jann Horn , Pedro Falcato , Hugh Dickins , Pasha Tatashin , Pratyush Yadav , "Matthew Wilcox (Oracle)" , Jan Kara , Zi Yan , Lance Yang , Rik van Riel , Harry Yoo , Alistair Popple , Nico Pache , Ryan Roberts , Dev Jain , Usama Arif , Kiryl Shutsemau , Matthew Brost , John Hubbard , Peter Xu , Will Deacon , "Aneesh Kumar K.V" , Nick Piggin , Oscar Salvador , Minchan Kim , Muchun Song , Xu Xin , Chengming Zhou , Chris Li , Kemeng Shi , Nhat Pham , Youngjun Park , Gregory Price , Joshua Hahn , Rakie Kim , Ying Huang , Jason Gunthorpe Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, kexec@lists.infradead.org, linux-fsdevel@vger.kernel.org, linux-arch@vger.kernel.org, linux-cxl@vger.kernel.org, Chris Mason , stable@vger.kernel.org, "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=1928; i=david@kernel.org; h=from:subject:message-id; bh=x0mKttz+HwDvoeWV/WYBCh6ori+6WykC26zRhsHss7s=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLLu358WvjBTPacmt4dPIdDk5tcpn+01cwTchGfUrDY2m /szsutzRykLgxgHg6yYIktQ8H2Dly/X1Va78THDzGFlAhnCwMUpABOZdZHhf0TH64MXTnQzGVbk qRb3zPUxmqEu+rl0VcOt4H8i+Tv3tjEyTI9WCD+789mjnlXPFlqk3zA4dezK72lrV9nE/lCeLr9 WlhcA X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam11 X-Rspamd-Queue-Id: C0A7440005 X-Stat-Signature: ax861wwz49os9jk1gshh4r3s9xrquixw X-Rspam-User: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=4.0.1 X-HE-Tag: 1793057199-973200 X-HE-Meta: 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 EC6ilzur jbW++9uTtcdZ+kZ0/sUZGRXuKx9m/mAozte8Rn5/jZdOuTwYqZVYbkH6ebf/5yBGZJnIZW/ODDyk8vhBtbzYUgzrX1sw4yyTWmfZhnM45/kZnBmXjvvt/xXj4yoR0TNuctyPqxiGSG8ap9x1oZrrnl0ssKDOBNZpxlK8420u1xnHegAL/CdJG+WN+/e3f1LdFVxWmPd4slS0rPenpx/rpP4pIGpRUP23Nubd7C0m9f2mH4OLVEf8Ff5/f2/cYtLfl0JMf+gTOWGW8gvFnrBV2Qq5BK6SfGl8WUluljz2O8veoAUCoutzLa/VlwPsip97Fm0h3GH98F4UEfs3dI5B2Nd0Z2fSVYESRptbrvsoSsG1be5l05neVln1Xmmz++HSVslM8SLwnDK69TaMdyqUHvjtYEg== 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 From: Chris Mason Radeon uses a non-NULL notifier->mm to decide whether to call mmu_interval_notifier_remove() when freeing a buffer object. __mmu_interval_notifier_insert() sets ->mm before validating the range, so a wrapping userptr range can leave ->mm set after insertion fails. Cleanup then tries to remove an unregistered notifier for which no mm reference was acquired. Set ->mm only after mmgrab(), once insertion can no longer fail. While we could fix radeon's code instead, setting ->mm on success only makes the code more robust. Fix generated by an LLM and sent by Chris Mason in private. Fixes: 3506ff69c3ec ("drm/radeon: use mmu_interval_notifier_insert") Cc: stable@vger.kernel.org Signed-off-by: Chris Mason [ david: simplify description ] Signed-off-by: David Hildenbrand (Arm) --- mm/mmu_notifier.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/mm/mmu_notifier.c b/mm/mmu_notifier.c index 2e20f88e162d7..a7bae5de5fedc 100644 --- a/mm/mmu_notifier.c +++ b/mm/mmu_notifier.c @@ -947,7 +947,6 @@ static int __mmu_interval_notifier_insert( struct mmu_notifier_subscriptions *subscriptions, unsigned long start, unsigned long length, const struct mmu_interval_notifier_ops *ops) { - interval_sub->mm = mm; interval_sub->ops = ops; RB_CLEAR_NODE(&interval_sub->interval_tree.rb); interval_sub->interval_tree.start = start; @@ -964,8 +963,12 @@ static int __mmu_interval_notifier_insert( if (WARN_ON(atomic_read(&mm->mm_users) <= 0)) return -EINVAL; - /* pairs with mmdrop in mmu_interval_notifier_remove() */ + /* + * Pairs with mmdrop in mmu_interval_notifier_remove(). Drivers take a + * non-NULL ->mm for "registered", so set it only with the reference. + */ mmgrab(mm); + interval_sub->mm = mm; /* * If some invalidate_range_start/end region is going on in parallel -- 2.43.0