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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EE65CC0032E for ; Wed, 25 Oct 2023 23:40:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229632AbjJYXk3 (ORCPT ); Wed, 25 Oct 2023 19:40:29 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41190 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229583AbjJYXk2 (ORCPT ); Wed, 25 Oct 2023 19:40:28 -0400 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0545013A for ; Wed, 25 Oct 2023 16:40:27 -0700 (PDT) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8DD52C433C8; Wed, 25 Oct 2023 23:40:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1698277226; bh=1Fu9+wCnGdSqfV8/TGjNO268mr/LpgDNvoaca5FJI4U=; h=Date:To:From:Subject:From; b=PMhHppHgdE1LCFU67kTmZxU4NZ0GxdELGsiN/91K3dDFhw8aovRyuWbtSYpieg3Mi E4lIdhkovTHNYHJ7EsGsi5GgANBR/29IXwd7zjmVZw+XwSQESqKu1zaj0mK9CPCCo5 bQkFNqGHsRaAU8skhXCSCIgjVglXrJT2FzaKURnM= Date: Wed, 25 Oct 2023 16:40:25 -0700 To: mm-commits@vger.kernel.org, hughd@google.com, akpm@linux-foundation.org From: Andrew Morton Subject: [folded-merged] mempolicy-migration-attempt-to-match-interleave-nodes-fix.patch removed from -mm tree Message-Id: <20231025234026.8DD52C433C8@smtp.kernel.org> Precedence: bulk Reply-To: linux-kernel@vger.kernel.org List-ID: X-Mailing-List: mm-commits@vger.kernel.org The quilt patch titled Subject: mempolicy: migration attempt to match interleave nodes: fix has been removed from the -mm tree. Its filename was mempolicy-migration-attempt-to-match-interleave-nodes-fix.patch This patch was dropped because it was folded into mempolicy-migration-attempt-to-match-interleave-nodes.patch ------------------------------------------------------ From: Hugh Dickins Subject: mempolicy: migration attempt to match interleave nodes: fix Date: Mon, 23 Oct 2023 23:50:42 -0700 (PDT) mm-unstable commit edd33b8807a1 ("mempolicy: migration attempt to match interleave nodes") added a second vma_iter search to do_mbind(), to determine the interleave index to be used in the MPOL_INTERLEAVE case. But sadly it added it just after the mmap_write_unlock(), leaving this new VMA search unprotected: and so syzbot reports suspicious RCU usage from lib/maple_tree.c:856. This could be fixed with an rcu_read_lock/unlock() pair (per Liam); but since we have been relying on the mmap_lock up to this point, it's slightly better to extend it over the new search too, for a well-defined result consistent with the policy this mbind() is establishing (rather than whatever might follow once the mmap_lock is dropped). Link: https://lkml.kernel.org/r/3311d544-fb05-a7f1-1b74-16aa0f6cd4fe@google.com Fixes: edd33b8807a1 ("mempolicy: migration attempt to match interleave nodes") Signed-off-by: Hugh Dickins Reported-by: syzbot+79fcba037b6df73756d3@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-mm/000000000000c05f1b0608657fde@google.com/ Signed-off-by: Andrew Morton --- mm/mempolicy.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/mm/mempolicy.c~mempolicy-migration-attempt-to-match-interleave-nodes-fix +++ a/mm/mempolicy.c @@ -1291,8 +1291,6 @@ static long do_mbind(unsigned long start } } - mmap_write_unlock(mm); - if (!err && !list_empty(&pagelist)) { /* Convert MPOL_DEFAULT's NULL to task or default policy */ if (!new) { @@ -1334,7 +1332,11 @@ static long do_mbind(unsigned long start mmpol.ilx -= page->index >> order; } } + } + mmap_write_unlock(mm); + + if (!err && !list_empty(&pagelist)) { nr_failed |= migrate_pages(&pagelist, alloc_migration_target_by_mpol, NULL, (unsigned long)&mmpol, MIGRATE_SYNC, _ Patches currently in -mm which might be from hughd@google.com are ext4-add-__gfp_nowarn-to-gfp_nowait-in-readahead.patch mm-mlock-avoid-folio_within_range-on-ksm-pages.patch hugetlbfs-drop-shared-numa-mempolicy-pretence.patch kernfs-drop-shared-numa-mempolicy-hooks.patch mempolicy-fix-migrate_pages2-syscall-return-nr_failed.patch mempolicy-trivia-delete-those-ancient-pr_debugs.patch mempolicy-trivia-slightly-more-consistent-naming.patch mempolicy-trivia-use-pgoff_t-in-shared-mempolicy-tree.patch mempolicy-mpol_shared_policy_init-without-pseudo-vma.patch mempolicy-remove-confusing-mpol_mf_lazy-dead-code.patch mm-add-page_rmappable_folio-wrapper.patch mempolicy-alloc_pages_mpol-for-numa-policy-without-vma.patch mempolicy-mmap_lock-is-not-needed-while-migrating-folios.patch mempolicy-migration-attempt-to-match-interleave-nodes.patch