[for-next 01/10] IB/mlx5: Fix kernel to user leak prevention logic
From: Saeed Mahameed <hidden>
Date: 2017-01-03 21:55:19
Also in:
linux-rdma
Subsystem:
infiniband subsystem, mellanox mlx5 ib driver, the rest · Maintainers:
Jason Gunthorpe, Leon Romanovsky, Linus Torvalds
From: Eli Cohen <eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
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 <eli-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Reviewed-by: Matan Barak <matanb-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
Signed-off-by: Leon Romanovsky <redacted>
Signed-off-by: Saeed Mahameed <saeedm-VPRAkNaXOzVWk0Htik3J/w@public.gmane.org>
---
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 86c61e7..852b5b7 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); }
--
2.7.4
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