4.14-stable review patch. If anyone has any objections, please let me know.
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From: Liam Mark lmark@codeaurora.org
commit 6d79bd5bb6c79a9dba4842040c9adf39e7806330 upstream.
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 lmark@codeaurora.org Acked-by: Laura Abbott labbott@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/staging/android/ion/ion_cma_heap.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+)
--- a/drivers/staging/android/ion/ion_cma_heap.c +++ b/drivers/staging/android/ion/ion_cma_heap.c @@ -21,6 +21,7 @@ #include <linux/err.h> #include <linux/cma.h> #include <linux/scatterlist.h> +#include <linux/highmem.h>
#include "ion.h"
@@ -51,6 +52,22 @@ static int ion_cma_allocate(struct ion_h 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;