diff options
authorRasmus Villemoes <>2021-06-24 18:40:04 -0700
committerLinus Torvalds <>2021-06-24 19:40:54 -0700
commitb08e50dd64489e3997029d204f761cb57a3762d2 (patch)
parentea6d0630100b285f059d0a8d8e86f38a46407536 (diff)
mm/page_alloc: __alloc_pages_bulk(): do bounds check before accessing array
In the event that somebody would call this with an already fully populated page_array, the last loop iteration would do an access beyond the end of page_array. It's of course extremely unlikely that would ever be done, but this triggers my internal static analyzer. Also, if it really is not supposed to be invoked this way (i.e., with no NULL entries in page_array), the nr_populated<nr_pages check could simply be removed instead. Link: Fixes: 0f87d9d30f21 ("mm/page_alloc: add an array-based interface to the bulk page allocator") Signed-off-by: Rasmus Villemoes <> Acked-by: Mel Gorman <> Reviewed-by: Andrew Morton <> Signed-off-by: Andrew Morton <> Signed-off-by: Linus Torvalds <>
1 files changed, 1 insertions, 1 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index d1f5de1c1283..7124bb00219d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5053,7 +5053,7 @@ unsigned long __alloc_pages_bulk(gfp_t gfp, int preferred_nid,
* Skip populated array elements to determine if any pages need
* to be allocated before disabling IRQs.
- while (page_array && page_array[nr_populated] && nr_populated < nr_pages)
+ while (page_array && nr_populated < nr_pages && page_array[nr_populated])
/* Use the single page allocator for one page. */