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dma-mapping: check pfn validity in dma_common_{mmap,get_sgtable} 

Check that the pfn returned from arch_dma_coherent_to_pfn refers to
a valid page and reject the mmap / get_sgtable requests otherwise.

Based on the arm implementation of the mmap and get_sgtable methods.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Vignesh Raghavendra <vigneshr@ti.com>
This commit is contained in:
Christoph Hellwig 2019-07-08 11:51:56 -07:00
parent 0653275001
commit 66d7780f18
1 changed files with 11 additions and 2 deletions
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13
kernel/dma/mapping.c
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@ -116,11 +116,16 @@ int dma_common_get_sgtable(struct device *dev, struct sg_table *sgt,
int ret;
if (!dev_is_dma_coherent(dev)) {
unsigned long pfn;
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
return -ENXIO;
page = pfn_to_page(arch_dma_coherent_to_pfn(dev, cpu_addr,
dma_addr));
/* If the PFN is not valid, we do not have a struct page */
pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
if (!pfn_valid(pfn))
return -ENXIO;
page = pfn_to_page(pfn);
} else {
page = virt_to_page(cpu_addr);
}
@ -170,7 +175,11 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
if (!dev_is_dma_coherent(dev)) {
if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN))
return -ENXIO;
/* If the PFN is not valid, we do not have a struct page */
pfn = arch_dma_coherent_to_pfn(dev, cpu_addr, dma_addr);
if (!pfn_valid(pfn))
return -ENXIO;
} else {
pfn = page_to_pfn(virt_to_page(cpu_addr));
}