| Message ID | 20220120033450.90164-1-guangming.cao@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v4] dma-buf: system_heap: Add a size check for allocation | expand |
On Wed, Jan 19, 2022 at 7:34 PM <guangming.cao@mediatek.com> wrote: > > From: Guangming <Guangming.Cao@mediatek.com> > > 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@mediatek.com> > --- > 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@linaro.org> thanks again -john
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; buffer = kzalloc(sizeof(*buffer), GFP_KERNEL); if (!buffer) return ERR_PTR(-ENOMEM);