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Commit 6d79bd5b authored by Liam Mark's avatar Liam Mark Committed by Greg Kroah-Hartman
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staging: android: ion: Zero CMA allocated memory 



Since commit 204f6722 ("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: 204f6722 ("staging: android: ion: Use CMA APIs directly")
Signed-off-by: default avatarLiam Mark <lmark@codeaurora.org>
Acked-by: default avatarLaura Abbott <labbott@redhat.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent ce8a3a9e

drivers/staging/android/ion/ion_cma_heap.c

+17 −0
Original line number Diff line number Diff line
@@ -12,6 +12,7 @@ 
#include <linux/err.h>

#include <linux/cma.h>

#include <linux/scatterlist.h>

#include <linux/highmem.h>



#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;