[PATCH] dma-buf: dma-heap: Add a size limitation for allocation
From: <hidden>
Date: 2021-12-17 09:40:37
Also in:
dri-devel, linux-arm-kernel, linux-media, lkml
Subsystem:
dma buffer sharing framework, dma-buf heaps framework, the rest · Maintainers:
Sumit Semwal, Christian König, Linus Torvalds
From: Guangming <redacted> Currently, there is no size check for allocation. If the alloc size is larger than DRAM, it will cause OOM issue. Besides, if it runs on a process that won't be killed by OOM flow, it will cause a kernel exception finally, and we couldn't find the correct memory usage by dma-buf dump api such as "dma_buf_debug_show" since the allocation is still on going and the corresponding dmabuf is not exported. However, it sounds not simple enough to adding a count to count how many pages has been allocated before allocating done. So adding a size limitation here to prevent this case. Signed-off-by: Guangming <redacted> Signed-off-by: jianjiao zeng <redacted> --- drivers/dma-buf/dma-heap.c | 3 +++ 1 file changed, 3 insertions(+)
diff --git a/drivers/dma-buf/dma-heap.c b/drivers/dma-buf/dma-heap.c
index 56bf5ad01ad5..8b75998a106c 100644
--- a/drivers/dma-buf/dma-heap.c
+++ b/drivers/dma-buf/dma-heap.c@@ -107,6 +107,9 @@ static long dma_heap_ioctl_allocate(struct file *file, void *data) if (heap_allocation->heap_flags & ~DMA_HEAP_VALID_HEAP_FLAGS) return -EINVAL; + if (heap_allocation->len / PAGE_SIZE > totalram_pages() / 2) + return -EINVAL; + fd = dma_heap_buffer_alloc(heap, heap_allocation->len, heap_allocation->fd_flags, heap_allocation->heap_flags);
--
2.17.1
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