From 0c6c88f7bb9f880a35573eda8dd87b16d94a0106 Mon Sep 17 00:00:00 2001 From: Maxim Mikityanskiy <maximmi@mellanox.com> Date: Fri, 3 May 2019 16:19:37 +0800 Subject: [PATCH] net/mlx5e: Fix use-after-free after xdp_return_frame [ Upstream commit 12fc512f5741443a03adde2ead20724da8ad550a ] xdp_return_frame releases the frame. It leads to releasing the page, so it's not allowed to access xdpi.xdpf->len after that, because xdpi.xdpf is at xdp->data_hard_start after convert_to_xdp_frame. This patch moves the memory access to precede the return of the frame. Fixes: 58b99ee3e3ebe ("net/mlx5e: Add support for XDP_REDIRECT in device-out side") Signed-off-by: Maxim Mikityanskiy <maximmi@mellanox.com> Signed-off-by: Saeed Mahameed <saeedm@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c index ca08443f744d..599114ab7821 100644 --- a/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c +++ b/drivers/net/ethernet/mellanox/mlx5/core/en/xdp.c @@ -227,9 +227,9 @@ bool mlx5e_poll_xdpsq_cq(struct mlx5e_cq *cq) sqcc++; if (is_redirect) { - xdp_return_frame(xdpi->xdpf); dma_unmap_single(sq->pdev, xdpi->dma_addr, xdpi->xdpf->len, DMA_TO_DEVICE); + xdp_return_frame(xdpi->xdpf); } else { /* Recycle RX page */ mlx5e_page_release(rq, &xdpi->di, true); @@ -263,9 +263,9 @@ void mlx5e_free_xdpsq_descs(struct mlx5e_xdpsq *sq) sq->cc++; if (is_redirect) { - xdp_return_frame(xdpi->xdpf); dma_unmap_single(sq->pdev, xdpi->dma_addr, xdpi->xdpf->len, DMA_TO_DEVICE); + xdp_return_frame(xdpi->xdpf); } else { /* Recycle RX page */ mlx5e_page_release(rq, &xdpi->di, false); -- GitLab