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| author | Kevin Grandemange <kevin.grandemange@allegrodvt.com> | 2020-03-12 15:41:45 +0000 |
|---|---|---|
| committer | Christoph Hellwig <hch@lst.de> | 2020-03-16 10:43:02 +0100 |
| commit | 286c21de32b904131f8cf6a36ce40b8b0c9c5da3 (patch) | |
| tree | f49e515ea7dae21ce3270d3fa1160dcc5dd9ae5a /kernel/dma | |
| parent | 11a48a5a18c63fd7621bb050228cebf13566e4d8 (diff) | |
| download | lwn-286c21de32b904131f8cf6a36ce40b8b0c9c5da3.tar.gz lwn-286c21de32b904131f8cf6a36ce40b8b0c9c5da3.zip | |
dma-coherent: fix integer overflow in the reserved-memory dma allocation
pageno is an int and the PAGE_SHIFT shift is done on an int,
overflowing if the memory is bigger than 2G
This can be reproduced using for example a reserved-memory of 4G
reserved-memory {
#address-cells = <2>;
#size-cells = <2>;
ranges;
reserved_dma: buffer@0 {
compatible = "shared-dma-pool";
no-map;
reg = <0x5 0x00000000 0x1 0x0>;
};
};
Signed-off-by: Kevin Grandemange <kevin.grandemange@allegrodvt.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/coherent.c | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/kernel/dma/coherent.c b/kernel/dma/coherent.c index 551b0eb7028a..2a0c4985f38e 100644 --- a/kernel/dma/coherent.c +++ b/kernel/dma/coherent.c @@ -134,7 +134,7 @@ static void *__dma_alloc_from_coherent(struct device *dev, spin_lock_irqsave(&mem->spinlock, flags); - if (unlikely(size > (mem->size << PAGE_SHIFT))) + if (unlikely(size > ((dma_addr_t)mem->size << PAGE_SHIFT))) goto err; pageno = bitmap_find_free_region(mem->bitmap, mem->size, order); @@ -144,8 +144,9 @@ static void *__dma_alloc_from_coherent(struct device *dev, /* * Memory was found in the coherent area. */ - *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT); - ret = mem->virt_base + (pageno << PAGE_SHIFT); + *dma_handle = dma_get_device_base(dev, mem) + + ((dma_addr_t)pageno << PAGE_SHIFT); + ret = mem->virt_base + ((dma_addr_t)pageno << PAGE_SHIFT); spin_unlock_irqrestore(&mem->spinlock, flags); memset(ret, 0, size); return ret; @@ -194,7 +195,7 @@ static int __dma_release_from_coherent(struct dma_coherent_mem *mem, int order, void *vaddr) { if (mem && vaddr >= mem->virt_base && vaddr < - (mem->virt_base + (mem->size << PAGE_SHIFT))) { + (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) { int page = (vaddr - mem->virt_base) >> PAGE_SHIFT; unsigned long flags; @@ -238,10 +239,10 @@ static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem, struct vm_area_struct *vma, void *vaddr, size_t size, int *ret) { if (mem && vaddr >= mem->virt_base && vaddr + size <= - (mem->virt_base + (mem->size << PAGE_SHIFT))) { + (mem->virt_base + ((dma_addr_t)mem->size << PAGE_SHIFT))) { unsigned long off = vma->vm_pgoff; int start = (vaddr - mem->virt_base) >> PAGE_SHIFT; - int user_count = vma_pages(vma); + unsigned long user_count = vma_pages(vma); int count = PAGE_ALIGN(size) >> PAGE_SHIFT; *ret = -ENXIO; |