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authorMarek Szyprowski <m.szyprowski@samsung.com>2015-08-28 09:41:39 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2015-12-09 13:40:07 -0500
commit98cc6d31fa7dde7beb1bccc51ad5c858d9ae5b04 (patch)
tree4e10205f3d7a1a81b5d11864930558c2c97ab5e8
parentc79f626810b7d20aca9cd935d8cfc3272ba7a054 (diff)
ARM: 8426/1: dma-mapping: add missing range check in dma_mmap()
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>
-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 8ca636cf8618..ac2b6b894320 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1355,12 +1355,17 @@ 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) {