On Wed, Jan 19, 2022 at 7:34 PM <guangming.cao@xxxxxxxxxxxx> wrote: > > From: Guangming <Guangming.Cao@xxxxxxxxxxxx> > > Add a size check for allocation since the allocation size should be > always less than the total DRAM size on system heap. > And it can prevent consuming too much time for invalid allocations. > > Signed-off-by: Guangming <Guangming.Cao@xxxxxxxxxxxx> > --- > drivers/dma-buf/heaps/system_heap.c | 7 +++++++ > 1 file changed, 7 insertions(+) > > diff --git a/drivers/dma-buf/heaps/system_heap.c b/drivers/dma-buf/heaps/system_heap.c > index 23a7e74ef966..bd6f255620e2 100644 > --- a/drivers/dma-buf/heaps/system_heap.c > +++ b/drivers/dma-buf/heaps/system_heap.c > @@ -347,6 +347,13 @@ 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 consuming > + * too much time for invalid allocations. > + */ > + if (len >> PAGE_SHIFT > totalram_pages()) > + return -EINVAL; Thanks so much for revising and sending this along! It looks good to me. Acked-by: John Stultz <john.stultz@xxxxxxxxxx> thanks again -john
