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authorMarek Szyprowski <m.szyprowski@samsung.com>2015-08-28 11:41:39 +0300
committerRussell King <rmk+kernel@arm.linux.org.uk>2015-10-03 18:36:45 +0300
commit371f0f085f629fc0f66695f572373ca4445a67ad (patch)
tree502ee1051eeaf183b6581739a77880635cd4c62e /arch/arm/mm
parentdb695c0509d6ec9046ee5e4c520a19fa17d9fce2 (diff)
downloadlinux-371f0f085f629fc0f66695f572373ca4445a67ad.tar.xz
ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()
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> Cc: stable@vger.kernel.org # v3.6+ Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/mm')
-rw-r--r--arch/arm/mm/dma-mapping.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1a7815e5421b..c0865867ef0d 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1407,12 +1407,17 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
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) {