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 C7355606A31C for ; Sat, 31 Oct 2026 09:47:51 +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=O0NtaK+z Received: by kanga.kvack.org (Postfix) id DBF016B05DE; Sat, 31 Oct 2026 05:47:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id D6EB66B05DF; Sat, 31 Oct 2026 05:47:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id C5EA26B05E0; Sat, 31 Oct 2026 05:47:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0011.hostedemail.com [216.40.44.11]) by kanga.kvack.org (Postfix) with ESMTP id 98D686B05DE for ; Sat, 31 Oct 2026 05:47:50 -0400 (EDT) Received: from smtpin02.hostedemail.com (lb01a-stub [10.200.18.249]) by unirelay05.hostedemail.com (Postfix) with ESMTP id 1FFC740954 for ; Sat, 31 Oct 2026 09:47:50 +0000 (UTC) X-FDA: 85382444700.02.249A6BD Received: from tor.source.kernel.org (tor.source.kernel.org [172.105.4.254]) by imf13.hostedemail.com (Postfix) with ESMTP id 5F01820005 for ; Sat, 31 Oct 2026 09:47:48 +0000 (UTC) Authentication-Results: imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=O0NtaK+z; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf13.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1793440068; 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=MOMq9Bo/X1WC/1XHARd8rol7WFT4eC651ZyNYelwklc=; b=IEpDLLeQBE7tvb/mM4OPM+Dzw48Q5GeQ74o309M1WLB/HpYVr0t1a2ljkZSnAVdlRdsWVX jl1zJPqflLNlQX3/Tei1A/52WSUpoqd4Uvi+68i8517U6raW1oFG3WJ67tZrjk67ub9Zjo GsQpsnxZHLKv47NPfyNri/OT7dTQ750= ARC-Authentication-Results: i=1; imf13.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20260515 header.b=O0NtaK+z; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf13.hostedemail.com: domain of david@kernel.org designates 172.105.4.254 as permitted sender) smtp.mailfrom=david@kernel.org ARC-Seal: i=1; a=rsa-sha256; d=hostedemail.com; s=arc-20220608; cv=none; t=1793440068; b=m8N9l9yeU891QYFXv0ZylQuyCYbb6msTgQtHNXYDGFBrBFNv1926/VAPPJZEb/C70zAQi0 wyNI2ouijTAajUGEzFWMUGc6ZBmuh7Vm63J22ij13l+Z52snxoKjvWwW7hSP/8AWcO074f d80JrR8HiPwoPmZFHhzHjrVq0o8hoRU= Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by tor.source.kernel.org (Postfix) with ESMTP id 026D8605CF; Sat, 31 Oct 2026 09:47:48 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id C3A551F00A17; Sat, 31 Oct 2026 09:47:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793440067; bh=MOMq9Bo/X1WC/1XHARd8rol7WFT4eC651ZyNYelwklc=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=O0NtaK+zWEOTRhNj0gXjp5K/M/sd/Bb90jRBQ8hxQ8xq45quOyyco+pKYVCv/e+rC jhx/NuTe97ABxZM0ywKwuAkVP/8zauiAIanlyRXXeBf2qcu+GpTU8kayuT4pTPc6wP wRjJ+K+z15pP5Xqspp73jz1pH/YGC4A2MVaJImK2lf4YyVGpw4whdScowfQepp5Q0Y jgsWDMbZxDZIlwn7aVN8S7cUelh61nAK+j4mm7sfZGhXW8W5C5pVHlip46qyApgRNG CrNeTqwbPD0FxGz/bDqMXdcwxziaTEUSFttaYaxf6kT6j7DISoD3IkgQ64ctLSxHq/ 4Vue8gfskydlw== From: "David Hildenbrand (Arm)" Date: Sat, 31 Oct 2026 10:39:58 +0100 Subject: [PATCH v3 29/47] 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: <20261031-fixes_core-v3-29-d6437171ecc3@kernel.org> References: <20261031-fixes_core-v3-0-d6437171ecc3@kernel.org> In-Reply-To: <20261031-fixes_core-v3-0-d6437171ecc3@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, Muhammad Usama Anjum , "David Hildenbrand (Arm)" X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2144; i=david@kernel.org; h=from:subject:message-id; bh=uqLLH/rw09nvp1DiWb73Ctop723Qk+Rw11zrHd74dEM=; b=owGbwMvMwCF2/OVpCdfQ3ZWMp9WSGLKebs+MUvecmTf/44Prj77M0zh96qmzHf/nTzWHYufcL FbkPxt5tqOUhUGMg0FWTJElKPi+wcuX62qr3fiYYeawMoEMYeDiFICJFDAw/DO/tLAiQThmaQNn jOOMa6u7DA9Y/vJat7y89k8vY2/2w6OMDPOV0/VfJLit+PLmfbHWH8PrXodfyJ0Kvdr66tLOiTJ Pn/ACAA== X-Developer-Key: i=david@kernel.org; a=openpgp; fpr=1BD9CAAD735C4C3A460DFCCA4DDE10F700FF835A X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 5F01820005 X-Stat-Signature: 9wt98i71hz711fdzzxxe54sjj39iomb6 X-Spam-Status: No, score=-18.8 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-Rspam-User: X-HE-Tag: 1793440068-315864 X-HE-Meta: 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 Wxc/0gcR cvh1xDWBSycFDn6zEFTA7j9i4H0jM+LV7tSfGKOYelCmBFp6mIJiy+MMDBv3Dds9Y7vSdX3vPrlm8AtVwU6U/iGVbzO57LDmA6xizBJn11e3gxNDVB8iuZ6jojEsRRx120yDVLZYLHF7wal7ZcymhnsJKjapvuwwaUQVSejs8po7Dnij/jtlmLzmIhQrBdU/rjW+FG2yipHBUxJtRAgOaGtLKMhpZuS8WDhb6fzLxJqLSnHda6I9iEqjrBzv7R8gLdOpFLQFe7JOiWBlImaUa9xk1D3VfhYpOi8acbUaRHnN/GXnlWbVO1rrXKKuqXM4ZpS3DDa4/G6on2d4LUPEy3BgNkvs9gUA0+mywpbTkoKOmSyeZgFJyZ7vzKCh8FDAJUYAZ/bFodsj9O3+sp+joypIlitQph/w0bOOELhSOWp1IerBlDkAGdrVHjNbtzYgiqFMz63C8QYTnwJewktYeBNLqwBBdORzuC9yo 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 ] Reviewed-by: Gregory Price (Meta) Tested-by: Gregory Price (Meta) Reviewed-by: Lorenzo Stoakes (ARM) Tested-by: Muhammad Usama Anjum 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