From de8d6e02efbdb259c67832ccf027d7ace9b91d5d Mon Sep 17 00:00:00 2001 From: Eli Cohen Date: Tue, 3 Jan 2017 23:55:19 +0200 Subject: [PATCH] IB/mlx5: Fix kernel to user leak prevention logic The logic was broken as it failed to update the response length for architectures with PAGE_SIZE larger than 4kB. As a result further extension of the ucontext response struct would fail. Fixes: d69e3bcf7976 ('IB/mlx5: Mmap the HCA's core clock register to user-space') Signed-off-by: Eli Cohen Reviewed-by: Matan Barak Signed-off-by: Leon Romanovsky Signed-off-by: Saeed Mahameed --- drivers/infiniband/hw/mlx5/main.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 86c61e73780e..852b5b7b4897 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -1148,13 +1148,13 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev, * pretend we don't support reading the HCA's core clock. This is also * forced by mmap function. */ - if (PAGE_SIZE <= 4096 && - field_avail(typeof(resp), hca_core_clock_offset, udata->outlen)) { - resp.comp_mask |= - MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_CORE_CLOCK_OFFSET; - resp.hca_core_clock_offset = - offsetof(struct mlx5_init_seg, internal_timer_h) % - PAGE_SIZE; + if (field_avail(typeof(resp), hca_core_clock_offset, udata->outlen)) { + if (PAGE_SIZE <= 4096) { + resp.comp_mask |= + MLX5_IB_ALLOC_UCONTEXT_RESP_MASK_CORE_CLOCK_OFFSET; + resp.hca_core_clock_offset = + offsetof(struct mlx5_init_seg, internal_timer_h) % PAGE_SIZE; + } resp.response_length += sizeof(resp.hca_core_clock_offset) + sizeof(resp.reserved2); } -- 2.20.1