On 2022/4/12 15:25, Tong Tiangen wrote:
In copy_highpage() the `kto` and `kfrom` local variables are pointers to
struct page, but these are used to hold arbitrary pointers to kernel memory
. Each call to page_address() returns a void pointer to memory associated
with the relevant page, and copy_page() expects void pointers to this
memory.
This inconsistency was introduced in commit 2563776b41c3 ("arm64: mte:
Tags-aware copy_{user_,}highpage() implementations") and while this
doesn't appear to be harmful in practice it is clearly wrong.
Correct this by making `kto` and `kfrom` void pointers.
Reviewed-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
Fixes: 2563776b41c3 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations")
Signed-off-by: Tong Tiangen <tongtiangen@xxxxxxxxxx>
Acked-by: Mark Rutland <mark.rutland@xxxxxxx>
---
arch/arm64/mm/copypage.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/mm/copypage.c b/arch/arm64/mm/copypage.c
index b5447e53cd73..0dea80bf6de4 100644
--- a/arch/arm64/mm/copypage.c
+++ b/arch/arm64/mm/copypage.c
@@ -16,8 +16,8 @@
void copy_highpage(struct page *to, struct page *from)
{
- struct page *kto = page_address(to);
- struct page *kfrom = page_address(from);
+ void *kto = page_address(to);
+ void *kfrom = page_address(from);
copy_page(kto, kfrom);
