Subject: Re: [PATCH] net/mlx4: fix MAC table total count corruption in __mlx4_unregister_mac()

From: Jakub Kicinski <[email-masked]>
Date: Mon, 26 Jan 2026 19:47:10 -0800

On Fri, 23 Jan 2026 02:39:07 +0800 Kery Qi wrote:
> In __mlx4_unregister_mac(), when operating in mf_bonded mode
> (SR-IOV with bonding), it appears that the code might be incorrectly
> decrementing table->total instead of dup_table->total when cleaning
> up the duplicate table entry.
> 
> If this is the case, it would cause the primary table's total counter
> to be decremented twice (once for itself and once when it should
> decrement the duplicate table), leading to counter corruption.
> Over time, table->total could become negative, which would
> break the "table->total == table->max" fullness check in
> __mlx4_register_mac().
> 
> The registration path correctly increments both counters:
>   ++table->total;
>   if (dup) {
>       ...
>       ++dup_table->total;
>   }
> 
> However, the unregistration path seems to have a typo:
>   --table->total;
>   if (dup) {
>       ...
>       --table->total; // Should this be --dup_table->total?

Looks legit, Tariq? Are you trying to find/dust off an mlx4 card? :)