Re: [PATCH] RDMA/nldev: validate dynamic counter attribute length

["yanjun.zhu" <yanjun.zhu@linux.dev>]

On 7/6/26 2:12 AM, Pengpeng Hou wrote:
> From: Pengpeng <pengpeng@iscas.ac.cn>
> 
> nldev_stat_set_counter_dynamic_doit() iterates nested hardware counter
> attributes and reads each entry with nla_get_u32(). The nested container
> proof does not by itself prove that each child attribute carries a
> four-byte payload.
> 
> Reject hardware counter entries whose payload is shorter than a u32
> before reading the index.
> 
> Signed-off-by: Pengpeng <pengpeng@iscas.ac.cn>
> ---
>   drivers/infiniband/core/nldev.c | 5 +++++
>   1 file changed, 5 insertions(+)
> 
> diff --git a/drivers/infiniband/core/nldev.c b/drivers/infiniband/core/nldev.c
> index 02a0a9c0a4a6..40b323131c7b 100644
> --- a/drivers/infiniband/core/nldev.c
> +++ b/drivers/infiniband/core/nldev.c
> @@ -2133,6 +2133,11 @@ static int nldev_stat_set_counter_dynamic_doit(struct nlattr *tb[],
>   
>   	nla_for_each_nested(entry_attr, tb[RDMA_NLDEV_ATTR_STAT_HWCOUNTERS],
>   			    rem) {
> +		if (nla_len(entry_attr) < sizeof(u32)) {

Maybe nla_len(entry_attr) > sizeof(u32) should also not be allowed?

As such, nla_len(entry_attr) != sizeof(u32) should be better?

Except the above, I am fine with this.

Reviewed-by: Zhu Yanjun <yanjun.zhu@linux.dev>

Zhu Yanjun

> +			ret = -EINVAL;
> +			goto out;
> +		}
> +
>   		index = nla_get_u32(entry_attr);
>   		if ((index >= stats->num_counters) ||
>   		    !(stats->descs[index].flags & IB_STAT_FLAG_OPTIONAL)) {