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| author | Thomas Tai <thomas.tai@oracle.com> | 2020-09-17 18:43:03 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2020-10-29 10:12:15 +0100 |
| commit | 4e57482e8440fac7137832629109730ea4b267aa (patch) | |
| tree | 6d3a954ea42e59296868c1b02e284e2cfe2b29cf /kernel | |
| parent | 48464c17bd642ee0b52c02a1ce22108b7345087b (diff) | |
| download | linux-stable-4e57482e8440fac7137832629109730ea4b267aa.tar.gz linux-stable-4e57482e8440fac7137832629109730ea4b267aa.tar.bz2 linux-stable-4e57482e8440fac7137832629109730ea4b267aa.zip | |
dma-direct: Fix potential NULL pointer dereference
[ Upstream commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 ]
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 <thomas.tai@oracle.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/dma/mapping.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 0d129421e75f..7133d5c6e1a6 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -144,6 +144,10 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, dma_addr_t addr; BUG_ON(!valid_dma_direction(dir)); + + if (WARN_ON_ONCE(!dev->dma_mask)) + return DMA_MAPPING_ERROR; + if (dma_map_direct(dev, ops)) addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else @@ -179,6 +183,10 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, int ents; BUG_ON(!valid_dma_direction(dir)); + + if (WARN_ON_ONCE(!dev->dma_mask)) + return 0; + if (dma_map_direct(dev, ops)) ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else @@ -213,6 +221,9 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, BUG_ON(!valid_dma_direction(dir)); + if (WARN_ON_ONCE(!dev->dma_mask)) + return DMA_MAPPING_ERROR; + /* Don't allow RAM to be mapped */ if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) return DMA_MAPPING_ERROR; |