From b9826a4929bbd4dcb245429fd7434145c4fcdc9b Mon Sep 17 00:00:00 2001 From: Jacopo Mondi Date: Wed, 18 Apr 2018 11:42:35 +0200 Subject: sh: mm: Fix unprotected access to struct device With commit ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") the generic DMA allocation function on which the SH 'dma_alloc_coherent()' function relies on, accesses the 'dma_pfn_offset' field of struct device. Unfortunately the 'dma_generic_alloc_coherent()' function is called from several places with a NULL struct device argument, halting the CPU during the boot process. This patch fixes the issue by protecting access to dev->dma_pfn_offset, with a trivial check for validity. It also passes a valid 'struct device' in the 'platform_resource_setup_memory()' function which is the main user of 'dma_alloc_coherent()', and inserts a WARN_ON() check to remind to future (and existing) bogus users of this function to provide a valid 'struct device' whenever possible. Fixes: ce88313069c36eef80f21fd7 ("arch/sh: make the DMA mapping operations observe dev->dma_pfn_offset") Signed-off-by: Jacopo Mondi Reviewed-by: Geert Uytterhoeven Reviewed-by: Thomas Petazzoni Signed-off-by: Rich Felker --- arch/sh/mm/consistent.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'arch') diff --git a/arch/sh/mm/consistent.c b/arch/sh/mm/consistent.c index 8ce98691d822..f1b44697ad68 100644 --- a/arch/sh/mm/consistent.c +++ b/arch/sh/mm/consistent.c @@ -59,7 +59,9 @@ void *dma_generic_alloc_coherent(struct device *dev, size_t size, split_page(pfn_to_page(virt_to_phys(ret) >> PAGE_SHIFT), order); - *dma_handle = virt_to_phys(ret) - PFN_PHYS(dev->dma_pfn_offset); + *dma_handle = virt_to_phys(ret); + if (!WARN_ON(!dev)) + *dma_handle -= PFN_PHYS(dev->dma_pfn_offset); return ret_nocache; } @@ -69,9 +71,12 @@ void dma_generic_free_coherent(struct device *dev, size_t size, unsigned long attrs) { int order = get_order(size); - unsigned long pfn = (dma_handle >> PAGE_SHIFT) + dev->dma_pfn_offset; + unsigned long pfn = dma_handle >> PAGE_SHIFT; int k; + if (!WARN_ON(!dev)) + pfn += dev->dma_pfn_offset; + for (k = 0; k < (1 << order); k++) __free_pages(pfn_to_page(pfn + k), 0); @@ -143,7 +148,7 @@ int __init platform_resource_setup_memory(struct platform_device *pdev, if (!memsize) return 0; - buf = dma_alloc_coherent(NULL, memsize, &dma_handle, GFP_KERNEL); + buf = dma_alloc_coherent(&pdev->dev, memsize, &dma_handle, GFP_KERNEL); if (!buf) { pr_warning("%s: unable to allocate memory\n", name); return -ENOMEM; -- cgit v1.2.3-59-g8ed1b