From f959dcd6ddfd29235030e8026471ac1b022ad2b0 Mon Sep 17 00:00:00 2001 From: Thomas Tai Date: Thu, 17 Sep 2020 18:43:03 +0200 Subject: dma-direct: Fix potential NULL pointer dereference When booting the kernel v5.9-rc4 on a VM, the kernel would panic when printing a warning message in swiotlb_map(). The dev->dma_mask must not be a NULL pointer when calling the dma mapping layer. A NULL pointer check can potentially avoid the panic. Signed-off-by: Thomas Tai Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Christoph Hellwig --- include/linux/dma-direct.h | 3 --- 1 file changed, 3 deletions(-) (limited to 'include/linux') diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 805010ea5346..2929685e88aa 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -62,9 +62,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, { dma_addr_t end = addr + size - 1; - if (!dev->dma_mask) - return false; - if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) return false; -- cgit v1.2.3