From: Andrew Morton <akpm@linux-foundation.org>
To: akpm@linux-foundation.org, brouer@redhat.com,
dan.carpenter@oracle.com, linux-mm@kvack.org,
mgorman@techsingularity.net, mgorman@techsinguliarity.net,
mm-commits@vger.kernel.org, torvalds@linux-foundation.org,
vbabka@suse.cz
Subject: [patch 22/24] mm/page_alloc: do bulk array bounds check after checking populated elements
Date: Thu, 24 Jun 2021 18:40:07 -0700 [thread overview]
Message-ID: <20210625014007.ThvxOTuQ9%akpm@linux-foundation.org> (raw)
In-Reply-To: <20210624183838.ac3161ca4a43989665ac8b2f@linux-foundation.org>
From: Mel Gorman <mgorman@techsingularity.net>
Subject: mm/page_alloc: do bulk array bounds check after checking populated elements
Dan Carpenter reported the following
The patch 0f87d9d30f21: "mm/page_alloc: add an array-based interface
to the bulk page allocator" from Apr 29, 2021, leads to the following
static checker warning:
mm/page_alloc.c:5338 __alloc_pages_bulk()
warn: potentially one past the end of array 'page_array[nr_populated]'
The problem can occur if an array is passed in that is fully populated.
That potentially ends up allocating a single page and storing it past the
end of the array. This patch returns 0 if the array is fully populated.
Link: https://lkml.kernel.org/r/20210618125102.GU30378@techsingularity.net
Fixes: 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator")
Signed-off-by: Mel Gorman <mgorman@techsinguliarity.net>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Jesper Dangaard Brouer <brouer@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
mm/page_alloc.c | 4 ++++
1 file changed, 4 insertions(+)
--- a/mm/page_alloc.c~mm-page_alloc-do-bulk-array-bounds-check-after-checking-populated-elements
+++ a/mm/page_alloc.c
@@ -5056,6 +5056,10 @@ unsigned long __alloc_pages_bulk(gfp_t g
while (page_array && nr_populated < nr_pages && page_array[nr_populated])
nr_populated++;
+ /* Already populated array? */
+ if (unlikely(page_array && nr_pages - nr_populated == 0))
+ return 0;
+
/* Use the single page allocator for one page. */
if (nr_pages - nr_populated == 1)
goto failed;
_
next prev parent reply other threads:[~2021-06-25 1:40 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-25 1:38 incoming Andrew Morton
2021-06-25 1:39 ` [patch 01/24] mm: page_vma_mapped_walk(): use page for pvmw->page Andrew Morton
2021-06-25 1:39 ` [patch 02/24] mm: page_vma_mapped_walk(): settle PageHuge on entry Andrew Morton
2021-06-25 1:39 ` [patch 03/24] mm: page_vma_mapped_walk(): use pmde for *pvmw->pmd Andrew Morton
2021-06-25 1:39 ` [patch 04/24] mm: page_vma_mapped_walk(): prettify PVMW_MIGRATION block Andrew Morton
2021-06-25 1:39 ` [patch 05/24] mm: page_vma_mapped_walk(): crossing page table boundary Andrew Morton
2021-06-25 1:39 ` [patch 06/24] mm: page_vma_mapped_walk(): add a level of indentation Andrew Morton
2021-06-25 1:39 ` [patch 07/24] mm: page_vma_mapped_walk(): use goto instead of while (1) Andrew Morton
2021-06-25 1:39 ` [patch 08/24] mm: page_vma_mapped_walk(): get vma_address_end() earlier Andrew Morton
2021-06-25 1:39 ` [patch 09/24] mm/thp: fix page_vma_mapped_walk() if THP mapped by ptes Andrew Morton
2021-06-25 1:39 ` [patch 10/24] mm/thp: another PVMW_SYNC fix in page_vma_mapped_walk() Andrew Morton
2021-06-25 1:39 ` [patch 11/24] nilfs2: fix memory leak in nilfs_sysfs_delete_device_group Andrew Morton
2021-06-25 1:39 ` [patch 12/24] mm/vmalloc: add vmalloc_no_huge Andrew Morton
2021-06-25 1:39 ` [patch 13/24] KVM: s390: prepare for hugepage vmalloc Andrew Morton
2021-06-25 1:39 ` [patch 14/24] mm/vmalloc: unbreak kasan vmalloc support Andrew Morton
2021-06-25 1:39 ` [patch 15/24] kthread_worker: split code for canceling the delayed work timer Andrew Morton
2021-06-25 1:39 ` [patch 16/24] kthread: prevent deadlock when kthread_mod_delayed_work() races with kthread_cancel_delayed_work_sync() Andrew Morton
2021-06-25 1:39 ` [patch 17/24] mm, futex: fix shared futex pgoff on shmem huge page Andrew Morton
2021-06-25 1:39 ` [patch 18/24] mm/memory-failure: use a mutex to avoid memory_failure() races Andrew Morton
2021-06-25 1:39 ` [patch 19/24] mm,hwpoison: return -EHWPOISON to denote that the page has already been poisoned Andrew Morton
2021-06-25 1:40 ` [patch 20/24] mm/hwpoison: do not lock page again when me_huge_page() successfully recovers Andrew Morton
2021-06-25 1:40 ` [patch 21/24] mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array Andrew Morton
2021-06-25 1:40 ` Andrew Morton [this message]
2021-06-25 1:40 ` [patch 23/24] MAINTAINERS: fix Marek's identity again Andrew Morton
2021-06-25 1:40 ` [patch 24/24] mailmap: add Marek's other e-mail address and identity without diacritics Andrew Morton
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