Am 20.01.22 um 08:08 schrieb guangming@mediatek.com:
From: Guangming
Add a size check for allocation since the allocation size should be
always less than the total DRAM size on system heap.
Adding this check can prevent comsuming too much time for invalid allocations.
Signed-off-by: Guangming
---
drivers/dma-buf/heaps/system_heap.c | 8
1 file changed, 8 insertions(+)
diff --git a/drivers/dma-buf/heaps/system_heap.c
b/drivers/dma-buf/heaps/system_heap.c
index 23a7e74ef966..459dc18bc4a2 100644
--- a/drivers/dma-buf/heaps/system_heap.c
+++ b/drivers/dma-buf/heaps/system_heap.c
@@ -347,6 +347,14 @@ static struct dma_buf *system_heap_allocate(struct
dma_heap *heap,
struct page *page, *tmp_page;
int i, ret = -ENOMEM;
+ /*
+* Size check. The "len" should be less than totalram since system_heap
+* memory is comes from system. Adding check here can prevent comsuming
+* too much time for invalid allocations.
+*/
+ if (len >> PAGE_SHIFT > totalram_pages())
Maybe use PFN_UP() or PFN_DOWN() here instead of open coding this.
Apart from that looks good to me.
Christian.
+ return ERR_PTR(-EINVAL);
+
buffer = kzalloc(sizeof(*buffer), GFP_KERNEL);
if (!buffer)
return ERR_PTR(-ENOMEM);
