Re: [PATCH net] net: use the full socket in sk_mc_loop()

[Eric Dumazet]

Le jeu. 8 oct. 2026 à 13:54, Theodor Arsenij Larionov-Trichkine
<theodorlarionov@xxxxxxxxx> a écrit :
>
> > (Was it a public syzbot report ?)
>
> No, this one is from a syzkaller-based fuzzer extended to target nftables.
> The fuzzer reached it through an nft "dup" rule in prerouting, which
> re-injects the SYN over loopback with its dst already attached, so the
> martian check never sees the multicast source.
>
> A raw IP_HDRINCL socket sending a SYN from 224.0.0.1 to an address on
> a dummy device also reaches it, without nft. That is the repro in v2.
>
> v2 with your inet_csk_route_req() check, the changelog, the trimmed
> splat and the repro is here:
> https://lore.kernel.org/netdev/20261008114942.1376889-1-theodorlarionov@xxxxxxxxx/
>
> Thanks for the review,
> Theodor

OK, but given the current flood of patches, we ask for a ~24 hours
delay between each version.

Note that the Fixes: tag could have been refined a bit, no big deal.