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authorChristoph Hellwig <hch@lst.de>2019-07-08 11:51:56 -0700
committerChristoph Hellwig <hch@lst.de>2019-07-24 17:28:54 +0200
commit66d7780f18eae0232827fcffeaded39a6a168236 (patch)
tree78bb0a0a0f8a11384dea615cc845185162ea531a /kernel
parent06532750010e06dd4b6d69983773677df7fc5291 (diff)
downloadlinux-66d7780f18eae0232827fcffeaded39a6a168236.tar.bz2
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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma/mapping.c13
1 files changed, 11 insertions, 2 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 1f628e7ac709..b945239621d8 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -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));
}