On 01/22/2018 09:46 AM, Liam Mark wrote:
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@xxxxxxxxxxxxxx>
---
Changes in v2:
- Clean up the commit message.
- Add 'Fixes:'
drivers/staging/android/ion/ion_cma_heap.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/drivers/staging/android/ion/ion_cma_heap.c b/drivers/staging/android/ion/ion_cma_heap.c
index 86196ffd2faf..91a98785607a 100644
--- a/drivers/staging/android/ion/ion_cma_heap.c
+++ b/drivers/staging/android/ion/ion_cma_heap.c
@@ -51,6 +51,8 @@ static int ion_cma_allocate(struct ion_heap *heap, struct ion_buffer *buffer,
if (!pages)
return -ENOMEM;
+ memset(page_address(pages), 0, size);
+
This won't work for highmem pages. You need to zero by page via
kmap_atomic in that case. You can use PageHighMem to separate the
paths.
Thanks,
Laura
table = kmalloc(sizeof(*table), GFP_KERNEL);
if (!table)
goto err;
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