From bc5c6eed0510f19b033ce7a7d3976e695e96785b Mon Sep 17 00:00:00 2001 From: Noa Osherovich Date: Sat, 4 Jun 2016 15:15:31 +0300 Subject: [PATCH] IB/mlx5: Limit query HCA clock When PAGE_SIZE is larger than 4K, the user shouldn't be able to query the HCA core clock. This counter is within 4KB boundary and the user-space shall not read information that's after this boundary. Fixes: b368d7cb8ceb7 ('IB/mlx5: Add hca_core_clock_offset to...') Signed-off-by: Majd Dibbiny Signed-off-by: Noa Osherovich Signed-off-by: Leon Romanovsky Signed-off-by: Doug Ledford --- drivers/infiniband/hw/mlx5/main.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c index 8845f4b9621b..05036dbb9804 100644 --- a/drivers/infiniband/hw/mlx5/main.c +++ b/drivers/infiniband/hw/mlx5/main.c @@ -991,7 +991,14 @@ static struct ib_ucontext *mlx5_ib_alloc_ucontext(struct ib_device *ibdev, if (field_avail(typeof(resp), cqe_version, udata->outlen)) resp.response_length += sizeof(resp.cqe_version); - if (field_avail(typeof(resp), hca_core_clock_offset, udata->outlen)) { + /* + * We don't want to expose information from the PCI bar that is located + * after 4096 bytes, so if the arch only supports larger pages, let's + * 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 = -- 2.20.1