On Mon, Sep 11, 2023 at 05:27:59PM -0600, Gustavo A. R. Silva wrote:
> Harden calls to struct_size() with size_add() and size_mul().
Specifically, make sure that open-coded arithmetic cannot cause an
overflow/wraparound. (i.e. it will stay saturated at SIZE_MAX.)
>
> Fixes: 467f432a521a ("RDMA/core: Split port and device counter sysfs
> attributes")
> Fixes: a4676388e2e2 ("RDMA/core: Simplify how the gid_attrs sysfs is created")
> Signed-off-by: Gustavo A. R. Silva <gustavo...@kernel.org>
Reviewed-by: Kees Cook <keesc...@chromium.org>
-Kees
> ---
> Changes in v2:
> - Update changelog text: remove the part about binary differences (it
> was added by mistake).
>
> drivers/infiniband/core/sysfs.c | 10 +++++-----
> 1 file changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/infiniband/core/sysfs.c b/drivers/infiniband/core/sysfs.c
> index ee59d7391568..ec5efdc16660 100644
> --- a/drivers/infiniband/core/sysfs.c
> +++ b/drivers/infiniband/core/sysfs.c
> @@ -903,7 +903,7 @@ alloc_hw_stats_device(struct ib_device *ibdev)
> * Two extra attribue elements here, one for the lifespan entry and
> * one to NULL terminate the list for the sysfs core code
> */
> - data = kzalloc(struct_size(data, attrs, stats->num_counters + 1),
> + data = kzalloc(struct_size(data, attrs, size_add(stats->num_counters,
> 1)),
> GFP_KERNEL);
> if (!data)
> goto err_free_stats;
> @@ -1009,7 +1009,7 @@ alloc_hw_stats_port(struct ib_port *port, struct
> attribute_group *group)
> * Two extra attribue elements here, one for the lifespan entry and
> * one to NULL terminate the list for the sysfs core code
> */
> - data = kzalloc(struct_size(data, attrs, stats->num_counters + 1),
> + data = kzalloc(struct_size(data, attrs, size_add(stats->num_counters,
> 1)),
> GFP_KERNEL);
> if (!data)
> goto err_free_stats;
> @@ -1140,7 +1140,7 @@ static int setup_gid_attrs(struct ib_port *port,
> int ret;
>
> gid_attr_group = kzalloc(struct_size(gid_attr_group, attrs_list,
> - attr->gid_tbl_len * 2),
> + size_mul(attr->gid_tbl_len, 2)),
> GFP_KERNEL);
> if (!gid_attr_group)
> return -ENOMEM;
> @@ -1205,8 +1205,8 @@ static struct ib_port *setup_port(struct ib_core_device
> *coredev, int port_num,
> int ret;
>
> p = kvzalloc(struct_size(p, attrs_list,
> - attr->gid_tbl_len + attr->pkey_tbl_len),
> - GFP_KERNEL);
> + size_add(attr->gid_tbl_len,
> attr->pkey_tbl_len)),
> + GFP_KERNEL);
> if (!p)
> return ERR_PTR(-ENOMEM);
> p->ibdev = device;
> --
> 2.34.1
>
--
Kees Cook
