This is a note to let you know that I've just added the patch titled
staging: android: ion: Zero CMA allocated memory
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: staging-android-ion-zero-cma-allocated-memory.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 6d79bd5bb6c79a9dba4842040c9adf39e7806330 Mon Sep 17 00:00:00 2001
From: Liam Mark lmark@codeaurora.org Date: Fri, 26 Jan 2018 09:48:18 -0800 Subject: staging: android: ion: Zero CMA allocated memory
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;
Patches currently in stable-queue which might be from lmark@codeaurora.org are
queue-4.14/staging-android-ion-zero-cma-allocated-memory.patch