From: Tong Tiangen tongtiangen@huawei.com
[ Upstream commit 921d161f15d6b090599f6a8c23f131969edbd1fa ]
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.
Fixes: 2563776b41c3 ("arm64: mte: Tags-aware copy_{user_,}highpage() implementations") Signed-off-by: Tong Tiangen tongtiangen@huawei.com Acked-by: Mark Rutland mark.rutland@arm.com Reviewed-by: Kefeng Wang wangkefeng.wang@huawei.com Link: https://lore.kernel.org/r/20220420030418.3189040-3-tongtiangen@huawei.com Signed-off-by: Catalin Marinas catalin.marinas@arm.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 70a71f38b6a9..24913271e898 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);