On Mon, Oct 07, 2024 at 11:28:16AM +0200, Florian Westphal wrote: > syzbot managed to call xt_cluster match via ebtables: > > WARNING: CPU: 0 PID: 11 at net/netfilter/xt_cluster.c:72 xt_cluster_mt+0x196/0x780 > [..] > ebt_do_table+0x174b/0x2a40 > > Module registers to NFPROTO_UNSPEC, but it assumes ipv4/ipv6 packet > processing. As this is only useful to restrict locally terminating > TCP/UDP traffic, register this for ipv4 and ipv6 family only. > > Pablo points out that this is a general issue, direct users of the > set/getsockopt interface can call into targets/matches that were only > intended for use with ip(6)tables. > > Check all UNSPEC matches and targets for similar issues: > > - matches and targets are fine except if they assume skb_network_header() > is valid -- this is only true when called from inet layer: ip(6) stack > pulls the ip/ipv6 header into linear data area. > - targets that return XT_CONTINUE or other xtables verdicts must be > restricted too, they are incompatbile with the ebtables traverser, e.g. > EBT_CONTINUE is a completely different value than XT_CONTINUE. > > Most matches/targets are changed to register for NFPROTO_IPV4/IPV6, as > they are provided for use by ip(6)tables. > > The MARK target is also used by arptables, so register for NFPROTO_ARP too. > > This change passes the selftests in iptables.git. Applied. I editted and appended this for the connbyte chunk: "While at it, bail out if connbytes fails to enable the corresponding conntrack family."
