From 56aaa0e8c92a5262e5bde7057972080e8b2f17d6 Mon Sep 17 00:00:00 2001 From: Kevin Grandemange Date: Thu, 12 Mar 2020 15:41:45 +0000 Subject: [PATCH] dma-coherent: fix integer overflow in the reserved-memory dma allocation [ Upstream commit 286c21de32b904131f8cf6a36ce40b8b0c9c5da3 ] 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 Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- kernel/dma/coherent.c | 13 +++++++------ 1 file 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;