dma-bufs follow different from normal memory rules, we don't need to sync it for the user. If the user space wants to directly access it, it should use proper primitives like DMA_BUF_IOCTL_SYNC. Fixes: a5c98e9424573 ("io_uring/zcrx: dmabuf backed zerocopy receive") Cc: stable@vger.kernel.org Signed-off-by: Pavel Begunkov --- io_uring/zcrx.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/io_uring/zcrx.c b/io_uring/zcrx.c index 6d7abb1636e7..17e554bb774f 100644 --- a/io_uring/zcrx.c +++ b/io_uring/zcrx.c @@ -1425,6 +1425,8 @@ static int io_pp_zc_init(struct page_pool *pp) if (pp->p.dma_dir != DMA_FROM_DEVICE) return -EOPNOTSUPP; + if (!ifq->kern_readable) + pp->dma_sync_for_cpu = false; refcount_inc(&ifq->refs); return 0; } -- 2.54.0