[Dnsmasq-discuss] [PATCH] Update DNS records after pruning DHCP leases

[Dominik Derigs]

Dear list,

we have added this commit to the currently running Pi-hole v6.0 beta. It 
was confirmed by multiple users to fix aforementioned issues.

https://github.com/pi-hole/FTL/pull/1965

Have a great weekend!
Dominik

On 29.04.24 20:44, Erik Karlsson wrote:
> From: Erik Karlsson <erik.karlsson at iopsys.eu>
>
> Not doing so can result in a use after free since the name for DHCP
> derived DNS records is represented as a pointer into the DHCP lease
> table. Update will only happen when necessary since lease_update_dns
> tests internally on dns_dirty and the force argument is zero.
>
> Signed-off-by: Erik Karlsson <erik.karlsson at iopsys.eu>
> ---
>   src/dnsmasq.c | 1 +
>   1 file changed, 1 insertion(+)
>
> diff --git a/src/dnsmasq.c b/src/dnsmasq.c
> index a9f26ae..1be3b82 100644
> --- a/src/dnsmasq.c
> +++ b/src/dnsmasq.c
> @@ -1518,6 +1518,7 @@ static void async_event(int pipe, time_t now)
>   	  {
>   	    lease_prune(NULL, now);
>   	    lease_update_file(now);
> +	    lease_update_dns(0);
>   	  }
>   #ifdef HAVE_DHCP6
>   	else if (daemon->doing_ra)