diff options
| author | Liu Shixin <liushixin2@huawei.com> | 2025-01-23 10:10:29 +0800 |
|---|---|---|
| committer | Andrew Morton <akpm@linux-foundation.org> | 2025-01-25 20:42:30 -0800 |
| commit | d1366e74342e75555af2648a2964deb2d5c92200 (patch) | |
| tree | 4f61c69609b06ec356bbdadca947855d198942fe /mm | |
| parent | 502269ab98b5b31428be23aa3871d297d916a90b (diff) | |
mm/compaction: fix UBSAN shift-out-of-bounds warning
syzkaller reported a UBSAN shift-out-of-bounds warning of (1UL << order)
in isolate_freepages_block(). The bogus compound_order can be any value
because it is union with flags. Add back the MAX_PAGE_ORDER check to fix
the warning.
Link: https://lkml.kernel.org/r/20250123021029.2826736-1-liushixin2@huawei.com
Fixes: 3da0272a4c7d ("mm/compaction: correctly return failure with bogus compound_order in strict mode")
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Reviewed-by: Kemeng Shi <shikemeng@huaweicloud.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Nanyong Sun <sunnanyong@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'mm')
| -rw-r--r-- | mm/compaction.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/mm/compaction.c b/mm/compaction.c index 07bd22789f07..0f49f060d251 100644 --- a/mm/compaction.c +++ b/mm/compaction.c @@ -631,7 +631,8 @@ static unsigned long isolate_freepages_block(struct compact_control *cc, if (PageCompound(page)) { const unsigned int order = compound_order(page); - if (blockpfn + (1UL << order) <= end_pfn) { + if ((order <= MAX_PAGE_ORDER) && + (blockpfn + (1UL << order) <= end_pfn)) { blockpfn += (1UL << order) - 1; page += (1UL << order) - 1; nr_scanned += (1UL << order) - 1; |