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staging: android: ion: Zero CMA allocated memory

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commit 6d79bd5bb6 upstream.

Since commit 204f672255 ("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: 204f672255 ("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>
This commit is contained in:
Liam Mark 2018-01-26 09:48:18 -08:00 committed by Greg Kroah-Hartman
parent af00a24c9e
commit 26023c9779
1 changed files with 17 additions and 0 deletions
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17
drivers/staging/android/ion/ion_cma_heap.c
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@ -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_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;