Patch "ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()" has been added to the 4.2-stable tree

[<gregkh@linuxfoundation.org>]

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

    ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()

to the 4.2-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:
     arm-8426-1-dma-mapping-add-missing-range-check-in-dma_mmap.patch
and it can be found in the queue-4.2 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 371f0f085f629fc0f66695f572373ca4445a67ad Mon Sep 17 00:00:00 2001
From: Marek Szyprowski <m.szyprowski@samsung.com>
Date: Fri, 28 Aug 2015 09:41:39 +0100
Subject: ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()

From: Marek Szyprowski <m.szyprowski@samsung.com>

commit 371f0f085f629fc0f66695f572373ca4445a67ad upstream.

dma_mmap() function in IOMMU-based dma-mapping implementation lacked
a check for valid range of mmap parameters (offset and buffer size), what
might have caused access beyond the allocated buffer. This patch fixes
this issue.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/arm/mm/dma-mapping.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1413,12 +1413,17 @@ static int arm_iommu_mmap_attrs(struct d
 	unsigned long uaddr = vma->vm_start;
 	unsigned long usize = vma->vm_end - vma->vm_start;
 	struct page **pages = __iommu_get_pages(cpu_addr, attrs);
+	unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
+	unsigned long off = vma->vm_pgoff;
 
 	vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
 
 	if (!pages)
 		return -ENXIO;
 
+	if (off >= nr_pages || (usize >> PAGE_SHIFT) > nr_pages - off)
+		return -ENXIO;
+
 	do {
 		int ret = vm_insert_page(vma, uaddr, *pages++);
 		if (ret) {


Patches currently in stable-queue which might be from m.szyprowski@samsung.com are

queue-4.2/arm-8427-1-dma-mapping-add-support-for-offset-parameter-in-dma_mmap.patch
queue-4.2/arm-8426-1-dma-mapping-add-missing-range-check-in-dma_mmap.patch