From 6d79bd5bb6c79a9dba4842040c9adf39e7806330 Mon Sep 17 00:00:00 2001 From: Liam Mark Date: Fri, 26 Jan 2018 09:48:18 -0800 Subject: [PATCH] staging: android: ion: Zero CMA allocated memory Since commit 204f672255c2 ("staging: android: ion: Use CMA APIs directly") the CMA API is now used directly and therefore the allocated memory is no longer automatically zeroed. Explicitly zero CMA allocated memory to ensure that no data is exposed to userspace. Fixes: 204f672255c2 ("staging: android: ion: Use CMA APIs directly") Signed-off-by: Liam Mark Acked-by: Laura Abbott Signed-off-by: Greg Kroah-Hartman --- drivers/staging/android/ion/ion_cma_heap.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c index 94e06925c712..49718c96bf9e 100644 --- a/drivers/staging/android/ion/ion_cma_heap.c +++ b/drivers/staging/android/ion/ion_cma_heap.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "ion.h" @@ -42,6 +43,22 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer, if (!pages) return -ENOMEM; + if (PageHighMem(pages)) { + unsigned long nr_clear_pages = nr_pages; + struct page *page = pages; + + while (nr_clear_pages > 0) { + void *vaddr = kmap_atomic(page); + + memset(vaddr, 0, PAGE_SIZE); + kunmap_atomic(vaddr); + page++; + nr_clear_pages--; + } + } else { + memset(page_address(pages), 0, size); + } + table = kmalloc(sizeof(*table), GFP_KERNEL); if (!table) goto err; -- 2.30.2