Re: [PATCH net 1/2] net/iucv: drop HiperSockets frames from other network namespaces

From: Alexandra Winter

Date: Mon Aug 24 2026 - 04:51:49 EST




On 21.08.26 13:42, Bryam Vargas wrote:
> Alexandra,
>
>> I am wondering whether a check of
>> + if (iucv_sk(sk)->hs_dev != dev)
>> + continue;
>>
>> would cover a broader range of issues.
>
> It does, and I'd rather have yours than mine. It covers three things at
> once: the namespace case, since hs_dev can only come from the init_net scan
> in iucv_sock_bind(); the transport case the earlier patch went after, since
> classic sockets have hs_dev == NULL and drop out of the walk; and delivery
> to a socket bound to a different HiperSockets device.
>
> I went looking for the regression it could carry -- an accept-queue child
> left without hs_dev, which would break connection setup -- and it isn't
> there. The child inherits at af_iucv.c:1908.
>
> One thing it doesn't reach, and it's why I'm not dropping both: the check
> sits after EBCASC() has already rewritten the transport header in place at
> :2073-2076, and a SYN matching no socket still takes the !iucv branch at
> :1872-1877, which swaps the frame and hands it to dev_queue_xmit(). So it
> replaces 1/2 and stays complementary to 2/2.
>
> Send yours and I'll drop 1/2.
>
> Thanks,
> Bryam
>


Thank you very much Bryam, I fully agree.

I've sent R-b for 2/2, and propose to take it as it is.

See https://lore.kernel.org/netdev/20260821125501.3718748-1-wintera@xxxxxxxxxxxxx/
for my proposal that should supersede 1/2.
Your review would be highly appreciated.