Re: [PATCH] wifi: mac80211: fix interger overflow in hwmp_route_info_get()

[Johannes Berg]

On Thu, 2024-12-26 at 07:47 +0000, Gavrilov Ilia wrote:
> Since the new_metric and last_hop_metric variables can reach
> the MAX_METRIC(0xffffffff) value, an integer overflow may occur
> when multiplying them by 10/9. It can lead to incorrect behavior.
> 
> Found by InfoTeCS on behalf of Linux Verification Center
> (linuxtesting.org) with SVACE.
> 
> -					      mult_frac(new_metric, 10, 9) :
> +					      mult_frac((u64)new_metric, 10, 9) :
> 

As you would expect, this doesn't build on 32-bit.

johannnes