From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 74F9FEDE; Fri, 15 Nov 2024 00:15:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731629738; cv=none; b=lzIuWR6eiFn6T2ekwVPg6ctxCT4fBQ74ayfHrb/NdGKCqrhugyyoNSInM44AMAd/h9UKNZvXvETYRKBzL9mjIyz4c7GvlKs6Ypm4lk3MRpdku6q8L7K7FbIdM2LSAi5skX1URzA3n7O9W14Ked3xjYXp9jEAFblrva4KqZmru0s= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731629738; c=relaxed/simple; bh=qtIf/XvE2L7S0s4UzV1eT0s98Kdh4Y4vXKEKcAjaQ5k=; h=Date:To:From:Subject:Message-Id; b=ehR//YeIcA4KGcxiugNGxN/maB/0oR33sQH29NIJ3q2U2SFJaYiVSMShs6DS/Okq0ZJQFf5MiYbd3M485NW8wFbRievv8m/suqcjM/eCq0hHd2PrmLqvtyHwS7RzptnN34+rcnAntqRlXuhuAhk5qpbKkFyr3btysjAyUs3deEk= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=Gmt5sAud; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="Gmt5sAud" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7A09AC4CECD; Fri, 15 Nov 2024 00:15:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1731629738; bh=qtIf/XvE2L7S0s4UzV1eT0s98Kdh4Y4vXKEKcAjaQ5k=; h=Date:To:From:Subject:From; b=Gmt5sAudpb6F8rM7JHcVRdPEyuVvE+nkX5fQglE1BDipHmzxh0o+FYCFrhEq/A18h 4VW/4QO5iJx81QU11tezOp/dVny+J5sb64yx5jsO/lLW77Sieg7HZvzv8kLZQbwC8I CQiDcNbBz+ZpqzcRv5Aj/t/Nn+cPflflb3VFqEbY= Date: Thu, 14 Nov 2024 16:15:33 -0800 To: mm-commits@vger.kernel.org,wangkefeng.wang@huawei.com,vbabka@suse.cz,sunnanyong@huawei.com,stable@vger.kernel.org,mgorman@techsingularity.net,david@redhat.com,alobakin@pm.me,tujinjiang@huawei.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-fix-null-pointer-dereference-in-alloc_pages_bulk_noprof.patch added to mm-hotfixes-unstable branch Message-Id: <20241115001537.7A09AC4CECD@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm: fix NULL pointer dereference in alloc_pages_bulk_noprof has been added to the -mm mm-hotfixes-unstable branch. Its filename is mm-fix-null-pointer-dereference-in-alloc_pages_bulk_noprof.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-null-pointer-dereference-in-alloc_pages_bulk_noprof.patch This patch will later appear in the mm-hotfixes-unstable branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Jinjiang Tu Subject: mm: fix NULL pointer dereference in alloc_pages_bulk_noprof Date: Wed, 13 Nov 2024 16:32:35 +0800 We triggered a NULL pointer dereference for ac.preferred_zoneref->zone in alloc_pages_bulk_noprof() when the task is migrated between cpusets. When cpuset is enabled, in prepare_alloc_pages(), ac->nodemask may be ¤t->mems_allowed. when first_zones_zonelist() is called to find preferred_zoneref, the ac->nodemask may be modified concurrently if the task is migrated between different cpusets. Assuming we have 2 NUMA Node, when traversing Node1 in ac->zonelist, the nodemask is 2, and when traversing Node2 in ac->zonelist, the nodemask is 1. As a result, the ac->preferred_zoneref points to NULL zone. In alloc_pages_bulk_noprof(), for_each_zone_zonelist_nodemask() finds a allowable zone and calls zonelist_node_idx(ac.preferred_zoneref), leading to NULL pointer dereference. __alloc_pages_noprof() fixes this issue by checking NULL pointer in commit ea57485af8f4 ("mm, page_alloc: fix check for NULL preferred_zone") and commit df76cee6bbeb ("mm, page_alloc: remove redundant checks from alloc fastpath"). To fix it, check NULL pointer for preferred_zoneref->zone. Link: https://lkml.kernel.org/r/20241113083235.166798-1-tujinjiang@huawei.com Fixes: 387ba26fb1cb ("mm/page_alloc: add a bulk page allocator") Signed-off-by: Jinjiang Tu Reviewed-by: Vlastimil Babka Cc: Alexander Lobakin Cc: David Hildenbrand Cc: Kefeng Wang Cc: Mel Gorman Cc: Nanyong Sun Cc: Signed-off-by: Andrew Morton --- mm/page_alloc.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) --- a/mm/page_alloc.c~mm-fix-null-pointer-dereference-in-alloc_pages_bulk_noprof +++ a/mm/page_alloc.c @@ -4607,7 +4607,8 @@ unsigned long alloc_pages_bulk_noprof(gf gfp = alloc_gfp; /* Find an allowed local zone that meets the low watermark. */ - for_each_zone_zonelist_nodemask(zone, z, ac.zonelist, ac.highest_zoneidx, ac.nodemask) { + z = ac.preferred_zoneref; + for_next_zone_zonelist_nodemask(zone, z, ac.highest_zoneidx, ac.nodemask) { unsigned long mark; if (cpusets_enabled() && (alloc_flags & ALLOC_CPUSET) && _ Patches currently in -mm which might be from tujinjiang@huawei.com are mm-fix-null-pointer-dereference-in-alloc_pages_bulk_noprof.patch