Patch "arm64: dma-mapping: always clear allocated buffers" has been added to the 3.14-stable tree

This is a note to let you know that I've just added the patch titled

arm64: dma-mapping: always clear allocated buffers

to the 3.14-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
arm64-dma-mapping-always-clear-allocated-buffers.patch
and it can be found in the queue-3.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Marek Szyprowski <[email protected]>
Date: Thu, 23 Apr 2015 12:46:16 +0100
Subject: arm64: dma-mapping: always clear allocated buffers

From: Marek Szyprowski <[email protected]>

commit 6829e274a623187c24f7cfc0e3d35f25d087fcc5 upstream.

Buffers allocated by dma_alloc_coherent() are always zeroed on Alpha, ARM (32bit), MIPS, PowerPC, x86/x86_64 and probably other architectures. It turned out that some drivers rely on this 'feature'. Allocated buffer might be also exposed to userspace with dma_mmap() call, so clearing it is desired from security point of view to avoid exposing random memory to userspace. This patch unifies dma_alloc_coherent() behavior on ARM64 architecture with other implementations by unconditionally zeroing allocated buffer.

---
 arch/arm64/mm/dma-mapping.c |    3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

@@ -54,8 +54,7 @@ static void *arm64_swiotlb_alloc_coheren
 
 		*dma_handle = phys_to_dma(dev, page_to_phys(page));
 		addr = page_address(page);
-		if (flags & __GFP_ZERO)
-			memset(addr, 0, size);
+		memset(addr, 0, size);
 		return addr;
 	} else {
 		return swiotlb_alloc_coherent(dev, size, dma_handle, flags);

Patches currently in stable-queue which might be from [email protected] are

queue-3.14/arm64-dma-mapping-always-clear-allocated-buffers.patch