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

[Geert Stappers]

On Tue, Oct 01, 2024 at 11:00:24AM +0200, 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)


That looks like a retransmit from April 2024.

It made it to the mailinglistpatchcollection, mlpc,
https://lists.sr.ht/~stappers/dnsmasqmlpc/patches/51909


When another retransmit a.k.a. reminder is needed,
please state something like "you might seen this before"
to save search time on "Hey, it looks familiar".


Groeten
Geert Stappers
-- 
Silence is hard to parse