The patch titled
Subject: mm: memcontrol: use flex_array_size() helper in memcpy()
has been added to the -mm tree. Its filename is
mm-memcontrol-use-flex_array_size-helper-in-memcpy.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-use-flex_array_size-helper-in-memcpy.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-use-flex_array_size-helper-in-memcpy.patch
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------------------------------------------------------
From: "Gustavo A. R. Silva" <gustavoars@xxxxxxxxxx>
Subject: mm: memcontrol: use flex_array_size() helper in memcpy()
Make use of the flex_array_size() helper to calculate the size of a
flexible array member within an enclosing structure.
This helper offers defense-in-depth against potential integer overflows,
while at the same time makes it explicitly clear that we are dealing with
a flexible array member.
Also, remove unnecessary braces.
Link: https://lkml.kernel.org/r/ddd60dae2d9aea1ccdd2be66634815c93696125e.1596214831.git.gustavoars@xxxxxxxxxx
Signed-off-by: Gustavo A. R. Silva <gustavoars@xxxxxxxxxx>
Acked-by: Michal Hocko <mhocko@xxxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--- a/mm/memcontrol.c~mm-memcontrol-use-flex_array_size-helper-in-memcpy
+++ a/mm/memcontrol.c
@@ -4253,10 +4253,9 @@ static int __mem_cgroup_usage_register_e
new->size = size;
/* Copy thresholds (if any) to new array */
- if (thresholds->primary) {
- memcpy(new->entries, thresholds->primary->entries, (size - 1) *
- sizeof(struct mem_cgroup_threshold));
- }
+ if (thresholds->primary)
+ memcpy(new->entries, thresholds->primary->entries,
+ flex_array_size(new, entries, size - 1));
/* Add new threshold */
new->entries[size - 1].eventfd = eventfd;
_
Patches currently in -mm which might be from gustavoars@xxxxxxxxxx are
mm-memcontrol-use-flex_array_size-helper-in-memcpy.patch
mm-memcontrol-use-the-preferred-form-for-passing-the-size-of-a-structure-type.patch
