From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1792832243; b=qjIyKqlOg3Co93YeQt3kopEx7p8v/hnmgERmOW7YUcJMM0+DXmcvpkONkWtwbPr8gRlP AglmWpodiwNHgrdP2c8KSN2s/a89CH79tCDQAqcoy7Z1oZ5RvHqFaX1TfuOMyU4TSwxKZ +C1g5jCLUixIsWp9rfU6jOrDPLIW2ImzivQ4GrxccY68IQNm+CFuMo70NAiSbi/3m74/q z9XmRs8r8pORVzbMeOuz0RRmSYLIMfhGgxdwHSqQdkEoVRfCLK3q2jiAYJoAS881feJ0D FHPI0s8x+NBvDecq4A3Zu8yT1R76PMH8bo1oRMnyJdTgIYJidg2+BtSCOjiyfttUZiA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1792832243; h=Received:DKIM-Signature:Date:To:From:Subject:Message-Id; bh=C7cAm1Lw6ANPQZaqPPZBrYmTu2y2HMuQFhXKFMLw2tk=; b=d+UmAYjmHFDQZaheFvRaajK2oNnLQZshbHJ0wqEqfDb5GgEqdu1ZGFfZQQc9XXd0czky Eug5x3yKWP9g9YI62OzdcAguYfvzkaDz5UIt4EzhI8pd7efXPlz1S6ui2FxZI9QS40LH1 uyRLEhxz5iJ2sqbp6m3yC8XnLotRtHfvr+p1NIv69I+ZgFHEhUKBbQfxAw0rz+xeOxbGS Hlc+7k9z13bYcb3IOpEvomc3tsNd5CqpEOrPrO8kyz0cX/nxWDet8fTGdrqDIbwFNjNAA eCi2UzEARclOfpgcxzBaEvoR9/MfnH15Si6xvNSegfCwVcqsVdJ+PUWVEodPtHzQBOA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=ohnqDKq4; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 37A9E606A321; Sat, 24 Oct 2026 08:57:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linux-foundation.org header.i=@linux-foundation.org header.a=rsa-sha256 header.s=korg header.b=ohnqDKq4 Received: by smtp.kernel.org (Postfix) with ESMTPSA id ABD3C1F01825; Sat, 24 Oct 2026 08:57:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1792832242; bh=C7cAm1Lw6ANPQZaqPPZBrYmTu2y2HMuQFhXKFMLw2tk=; h=Date:To:From:Subject; b=ohnqDKq4zx/yLIRp/kYacLm3FRJxuYw0qd9ZFlbFJHvu0+7MimeHk7gGOfD1wIHuf I0duRaYWcaYHyxvbIW/Rhi7QECGk0C6iOLcx84gwboxyv4ycJcMv6KbDGqDdP8s3TP rJBu92id/s7MImHB9QPIA2rUixuqqFLWG6gBt7a8= Date: Sat, 24 Oct 2026 01:57:22 -0700 To: mm-commits@vger.kernel.org,vbabka@kernel.org,stable@vger.kernel.org,rppt@kernel.org,riel@surriel.com,pfalcato@suse.de,peterx@redhat.com,osalvador@suse.de,nao.horiguchi@gmail.com,muchun.song@linux.dev,mgorman@techsingularity.net,ljs@kernel.org,linmiaohe@huawei.com,liam@infradead.org,lance.yang@linux.dev,kas@kernel.org,josef@toxicpanda.com,jannh@google.com,agl@us.ibm.com,david@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-stable] mm-hugetlb-fix-use-after-free-in-hugetlb_mfill_atomic_pte.patch removed from -mm tree Message-Id: <20261024085722.ABD3C1F01825@smtp.kernel.org> X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list The quilt patch titled Subject: mm/hugetlb: fix use-after-free in hugetlb_mfill_atomic_pte() has been removed from the -mm tree. Its filename was mm-hugetlb-fix-use-after-free-in-hugetlb_mfill_atomic_pte.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: "David Hildenbrand (Arm)" Subject: mm/hugetlb: fix use-after-free in hugetlb_mfill_atomic_pte() Date: Thu, 15 Oct 2026 18:07:09 +0200 Let's fix another instance where we use a folio after dropping the PTL, where someone else could e.g., MADV_DONTNEED it once we drop the PTL, making us trigger a use-after-free on the folio. Link: https://lore.kernel.org/20261015-urgent_fixes-v1-3-42796911043b@kernel.org Fixes: cb6acd01e2e4 ("hugetlbfs: fix races and page leaks during migration") Fixes: 1c9e8def43a3 ("userfaultfd: hugetlbfs: add UFFDIO_COPY support for shared mappings") Signed-off-by: David Hildenbrand (Arm) Signed-off-by: Andrew Morton Reported-by: Lorenzo Stoakes (ARM) Reviewed-by: Lorenzo Stoakes (ARM) Acked-by: Muchun Song Reviewed-by: Lance Yang Cc: Liam R. Howlett Cc: Vlastimil Babka Cc: Jann Horn Cc: Pedro Falcato Cc: Oscar Salvador Cc: Miaohe Lin Cc: Naoya Horiguchi Cc: Adam Litke Cc: Mel Gorman Cc: Rik van Riel Cc: Peter Xu Cc: Kiryl Shutsemau Cc: Mike Rapoport Cc: Josef Bacik Cc: --- mm/hugetlb.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c~mm-hugetlb-fix-use-after-free-in-hugetlb_mfill_atomic_pte +++ a/mm/hugetlb.c @@ -6520,11 +6520,16 @@ int hugetlb_mfill_atomic_pte(pte_t *dst_ /* No need to invalidate - it was non-present before */ update_mmu_cache(dst_vma, dst_addr, dst_pte); - spin_unlock(ptl); if (!is_continue) folio_set_hugetlb_migratable(folio); if (vm_shared || is_continue) folio_unlock(folio); + + /* + * Hold the PTL until we're done with the folio: the page table owns the + * folio reference now. + */ + spin_unlock(ptl); ret = 0; out: return ret; _ Patches currently in -mm which might be from david@kernel.org are mm-fix-address-wraparound-when-scanning-large-folio-ptes.patch mm-hugetlb-disable-pmd-sharing-for-uffd-missing-mode.patch mm-vma-write-lock-source-vma-before-duplicating-it-in-__split_vma.patch mm-madvise-preserve-vma_softdirty_bit-when-changing-anonymous-names.patch