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authorLiam Mark <lmark@codeaurora.org>2018-01-26 09:48:18 -0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-03-28 18:23:04 +0200
commitc7674a71bc3848ee604bd714b0ab0a51c3ba76c4 (patch)
tree076493938ba71f6c8dcb27e4221a890ab8e826b1 /drivers
parente8689b8bbae997a4afb22aabcfca7f864d4c820d (diff)
staging: android: ion: Zero CMA allocated memory
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>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/staging/android/ion/ion_cma_heap.c17
1 files changed, 17 insertions, 0 deletions
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 86196ffd2faf..fa3e4b7e0c9f 100644
--- 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_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;