Commit b51e4b0a authored by Eli Cohen's avatar Eli Cohen Committed by Greg Kroah-Hartman

IB/mlx5: Fix kernel to user leak prevention logic

commit de8d6e02 upstream.

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: d69e3bcf ('IB/mlx5: Mmap the HCA's core clock register to user-space')
Signed-off-by: default avatarEli Cohen <eli@mellanox.com>
Reviewed-by: default avatarMatan Barak <matanb@mellanox.com>
Signed-off-by: default avatarLeon Romanovsky <leon@kernel.org>
Signed-off-by: default avatarSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent dca02651
......@@ -1105,13 +1105,13 @@ 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);
}
......
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