The patch titled
Subject: mm/z3fold: avoid possible underflow in z3fold_alloc()
has been removed from the -mm tree. Its filename was
mm-z3fold-avoid-possible-underflow-in-z3fold_alloc.patch
This patch was dropped because it was merged into mainline or a subsystem tree
------------------------------------------------------
From: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Subject: mm/z3fold: avoid possible underflow in z3fold_alloc()
It is not enough to just make sure the z3fold header is not larger than
the page size. When z3fold header is equal to PAGE_SIZE, we would
underflow when check alloc size against PAGE_SIZE - ZHDR_SIZE_ALIGNED -
CHUNK_SIZE in z3fold_alloc(). Make sure there has remaining spaces for
its buddy to fix this theoretical issue.
Link: https://lkml.kernel.org/r/20210619093151.1492174-3-linmiaohe@xxxxxxxxxx
Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx>
Reviewed-by: Vitaly Wool <vitaly.wool@xxxxxxxxxxxx>
Cc: Hillf Danton <hdanton@xxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/z3fold.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)
--- a/mm/z3fold.c~mm-z3fold-avoid-possible-underflow-in-z3fold_alloc
+++ a/mm/z3fold.c
@@ -1803,8 +1803,11 @@ static int __init init_z3fold(void)
{
int ret;
- /* Make sure the z3fold header is not larger than the page size */
- BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE);
+ /*
+ * Make sure the z3fold header is not larger than the page size and
+ * there has remaining spaces for its buddy.
+ */
+ BUILD_BUG_ON(ZHDR_SIZE_ALIGNED > PAGE_SIZE - CHUNK_SIZE);
ret = z3fold_mount();
if (ret)
return ret;
_
Patches currently in -mm which might be from linmiaohe@xxxxxxxxxx are
mm-zsmallocc-combine-two-atomic-ops-in-zs_pool_dec_isolated.patch
