Re: [PATCH net] ipvs: Fix clamp() order in ip_vs_conn_init()

On Wed, Dec 11, 2024 at 2:16 PM Dan Carpenter <[email protected]> wrote:
>
> We recently added some build time asserts to detect incorrect calls to
> clamp and it detected this bug which breaks the build.  The variable
> in this clamp is "max_avail" and it should be the first argument.  The
> code currently is the equivalent to max = max(max_avail, max).
>
> Reported-by: Linux Kernel Functional Testing <[email protected]>
> Closes: https://lore.kernel.org/all/CA+G9fYsT34UkGFKxus63H6UVpYi5GRZkezT9MRLfAbM3f6ke0g@mail.gmail.com/
> Fixes: 4f325e26277b ("ipvs: dynamically limit the connection hash table")
> Signed-off-by: Dan Carpenter <[email protected]>
> ---
> I've been trying to add stable CC's to my commits but I'm not sure the
> netdev policy on this.  Do you prefer to add them yourself?
>
>  net/netfilter/ipvs/ip_vs_conn.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/net/netfilter/ipvs/ip_vs_conn.c b/net/netfilter/ipvs/ip_vs_conn.c
> index 98d7dbe3d787..9f75ac801301 100644
> --- a/net/netfilter/ipvs/ip_vs_conn.c
> +++ b/net/netfilter/ipvs/ip_vs_conn.c
> @@ -1495,7 +1495,7 @@ int __init ip_vs_conn_init(void)
>         max_avail -= 2;         /* ~4 in hash row */
>         max_avail -= 1;         /* IPVS up to 1/2 of mem */
>         max_avail -= order_base_2(sizeof(struct ip_vs_conn));
> -       max = clamp(max, min, max_avail);
> +       max = clamp(max_avail, min, max);
>         ip_vs_conn_tab_bits = clamp_val(ip_vs_conn_tab_bits, min, max);
>         ip_vs_conn_tab_size = 1 << ip_vs_conn_tab_bits;
>         ip_vs_conn_tab_mask = ip_vs_conn_tab_size - 1;
> --
> 2.45.2
>

Tested-by: Bartosz Golaszewski <[email protected]>
Reviewed-by: Bartosz Golaszewski <[email protected]>