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>
1 file changed
