From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1) server-digest SHA256) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9CF15606A31A for ; Fri, 30 Oct 2026 03:42:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key, unprotected) header.d=lists.infradead.org header.i=@lists.infradead.org header.a=rsa-sha256 header.s=bombadil.20210309 header.b=vGH2W7cx; dkim=pass (2048-bit key, unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=MTA6YZJW DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Reply-To:List-Subscribe: List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id:Date: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Cc:To:Subject: From:Message-ID:MIME-Version:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Unsubscribe-Post:List-Owner; bh=u5xzret16o3iRVcvdLYAIgiyC5Y+uB5cEUow+F10Mo0=; b=vGH2W7cxYSIbvZSIjw/PeIpO1+ 7xi2Ep7ZCUP4yYI4zuFEyG0ImpM5G+3FHT7eWNS8Ef9PGCipVeAYQpCSmrRwE4NI073s4idXC1yvC FjNqj3fB2mlET3OxTBswyyqVm1VjtXIcBi56ZMkzpDoS0U740vj8jAP/1hEd4e5qZvak9FyCFrrKu Y2+tAVb094dO8cvDZTO/PM4MqKV+u2KWNqmHgT1ITENqZupQ4QYVQZo89w8D88ieI62hWp//E+DL0 R+lfMZFZIEY/g44rr7Fwb2ClNOeds8mjBqcewoRIeA/X7zCfSPEq1HcI4nxgDJum9QxM62npHTv/V S42juu3g==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdVq-0000000AlLd-1E6S; Fri, 30 Oct 2026 03:42:42 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.100.1 #2 (Red Hat Linux)) id 1xMdVo-0000000AlKi-2oT4 for kexec@lists.infradead.org; Fri, 30 Oct 2026 03:42:40 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 57E4A406FB; Fri, 30 Oct 2026 03:42:40 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id A27BF1F000C1; Fri, 30 Oct 2026 03:42:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1793331760; bh=u5xzret16o3iRVcvdLYAIgiyC5Y+uB5cEUow+F10Mo0=; h=From:Subject:Reply-To:To:Cc:In-Reply-To:References:Date; b=MTA6YZJWv0ySaGWoHElnL+j3pDonr6tYGaoMQQStrhsGmlXTzU46Jh27Lpt92yty5 j6qWLR2ecmk5hNASU1Uhm1OacS+njLqFQBGcr4H6QgNF9UKOqJVAe1I3lNtYegeWS4 w+v137TVz+7ra6pyLZdpZpYgOcVMzETpvo/d1TE9guCgIhZMpvTdfAhdTLepOgpJhA GNVnnKyc478nmGREx3h7Kp3saR4axQYZrmvhm9qHaWrxK33wqE0bBPYIQitGulRhv0 XPlehyJFdNSd/GVTkexwwSaQ2gNUe4Ga7BoZ2/+UKSyXh+v9KQgpUYJMMYhIg7xEwP j3cRTJlCGFCMw== Message-ID: From: sashiko-bot@kernel.org Subject: Re: [PATCH v2 45/47] mm/cma: don't release CMA pages still in use To: =?utf-8?b?RGF2aWQgSGlsZGVuYnJhbmQgKEFybSk=?= , "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" , =?utf-8?b?TWF0dGhldyBXaWxjb3ggKE9yYWNsZSk=?= , "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: kexec@lists.infradead.org In-Reply-To: <20261029-fixes_core-v2-45-a64ce7f83abb@kernel.org> References: <20261029-fixes_core-v2-0-a64ce7f83abb@kernel.org> <20261029-fixes_core-v2-45-a64ce7f83abb@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Date: Fri, 30 Oct 2026 03:42:37 +0000 X-BeenThere: kexec@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: sashiko-reviews@lists.linux.dev Sender: "kexec" X-Spam-Status: No, score=-10.9 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 X-Archived-By: > From: Rik van Riel >=20 > When a driver calls dma_free_contiguous() before quiescing DMA, the > page might still have a reference from the device. > put_page_testzero() there returns false, WARN fires, but the code proceeds > to free_contig_frozen_range() putting a live page onto buddy and clearing > the bitmap. A subsequent allocation can hand the same PFN to a new > owner while the original holder still references it. >=20 > A concurrent put_page() that drops the last reference between the > testzero loop and free_contig_frozen_range() can double-queue the page > via page->lru, corrupting buddy lists. >=20 > Avoid the corruption by not freeing a CMA region if any of the > pages inside are still in use. >=20 > Make it explicit in the warning that the driver allowed a leak. >=20 > While at it, use page_ref_freeze() to make the semantics clearer and > switch to pr_warn_ratelimited(). >=20 > Fixes: 9bda131c6093 ("mm: cma: add cma_alloc_frozen{_compound}()") > Cc: stable@vger.kernel.org > Signed-off-by: Rik van Riel > Link: https://patch.msgid.link/20260811132045.5f114772@fangorn > [ david: use page_ref_freeze() + pr_warn_ratelimited() ] > Acked-by: Lorenzo Stoakes (ARM) > Acked-by: Muchun Song > Signed-off-by: David Hildenbrand (Arm) Sashiko has reviewed this patch and found no issues. --=20 Sashiko AI review =C2=B7 https://sashiko.dev/#/patchset/20261029-fixes_core= -v2-0-a64ce7f83abb@kernel.org?part=3D45