From 0bfcb7b71e735560077a42847f69597ec7dcc326 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Mon, 7 Oct 2024 11:28:16 +0200 Subject: netfilter: xtables: avoid NFPROTO_UNSPEC where needed 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. While at it, bail out if connbytes fails to enable the corresponding conntrack family. This change passes the selftests in iptables.git. Reported-by: syzbot+256c348558aa5cf611a9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netfilter-devel/66fec2e2.050a0220.9ec68.0047.GAE@google.com/ Fixes: 0269ea493734 ("netfilter: xtables: add cluster match") Signed-off-by: Florian Westphal Co-developed-by: Pablo Neira Ayuso Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_TRACE.c | 35 ++++++++++++++++++++++++----------- 1 file changed, 24 insertions(+), 11 deletions(-) (limited to 'net/netfilter/xt_TRACE.c') diff --git a/net/netfilter/xt_TRACE.c b/net/netfilter/xt_TRACE.c index 5582dce98cae..f3fa4f11348c 100644 --- a/net/netfilter/xt_TRACE.c +++ b/net/netfilter/xt_TRACE.c @@ -29,25 +29,38 @@ trace_tg(struct sk_buff *skb, const struct xt_action_param *par) return XT_CONTINUE; } -static struct xt_target trace_tg_reg __read_mostly = { - .name = "TRACE", - .revision = 0, - .family = NFPROTO_UNSPEC, - .table = "raw", - .target = trace_tg, - .checkentry = trace_tg_check, - .destroy = trace_tg_destroy, - .me = THIS_MODULE, +static struct xt_target trace_tg_reg[] __read_mostly = { + { + .name = "TRACE", + .revision = 0, + .family = NFPROTO_IPV4, + .table = "raw", + .target = trace_tg, + .checkentry = trace_tg_check, + .destroy = trace_tg_destroy, + .me = THIS_MODULE, + }, +#if IS_ENABLED(CONFIG_IP6_NF_IPTABLES) + { + .name = "TRACE", + .revision = 0, + .family = NFPROTO_IPV6, + .table = "raw", + .target = trace_tg, + .checkentry = trace_tg_check, + .destroy = trace_tg_destroy, + }, +#endif }; static int __init trace_tg_init(void) { - return xt_register_target(&trace_tg_reg); + return xt_register_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg)); } static void __exit trace_tg_exit(void) { - xt_unregister_target(&trace_tg_reg); + xt_unregister_targets(trace_tg_reg, ARRAY_SIZE(trace_tg_reg)); } module_init(trace_tg_init); -- cgit v1.2.3 From 306ed1728e8438caed30332e1ab46b28c25fe3d8 Mon Sep 17 00:00:00 2001 From: Pablo Neira Ayuso Date: Sun, 20 Oct 2024 14:49:51 +0200 Subject: netfilter: xtables: fix typo causing some targets not to load on IPv6 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit - There is no NFPROTO_IPV6 family for mark and NFLOG. - TRACE is also missing module autoload with NFPROTO_IPV6. This results in ip6tables failing to restore a ruleset. This issue has been reported by several users providing incomplete patches. Very similar to Ilya Katsnelson's patch including a missing chunk in the TRACE extension. Fixes: 0bfcb7b71e73 ("netfilter: xtables: avoid NFPROTO_UNSPEC where needed") Reported-by: Ignat Korchagin Reported-by: Ilya Katsnelson Reported-by: Krzysztof Olędzki Signed-off-by: Pablo Neira Ayuso --- net/netfilter/xt_NFLOG.c | 2 +- net/netfilter/xt_TRACE.c | 1 + net/netfilter/xt_mark.c | 2 +- 3 files changed, 3 insertions(+), 2 deletions(-) (limited to 'net/netfilter/xt_TRACE.c') diff --git a/net/netfilter/xt_NFLOG.c b/net/netfilter/xt_NFLOG.c index d80abd6ccaf8..6dcf4bc7e30b 100644 --- a/net/netfilter/xt_NFLOG.c +++ b/net/netfilter/xt_NFLOG.c @@ -79,7 +79,7 @@ static struct xt_target nflog_tg_reg[] __read_mostly = { { .name = "NFLOG", .revision = 0, - .family = NFPROTO_IPV4, + .family = NFPROTO_IPV6, .checkentry = nflog_tg_check, .destroy = nflog_tg_destroy, .target = nflog_tg, diff --git a/net/netfilter/xt_TRACE.c b/net/netfilter/xt_TRACE.c index f3fa4f11348c..a642ff09fc8e 100644 --- a/net/netfilter/xt_TRACE.c +++ b/net/netfilter/xt_TRACE.c @@ -49,6 +49,7 @@ static struct xt_target trace_tg_reg[] __read_mostly = { .target = trace_tg, .checkentry = trace_tg_check, .destroy = trace_tg_destroy, + .me = THIS_MODULE, }, #endif }; diff --git a/net/netfilter/xt_mark.c b/net/netfilter/xt_mark.c index f76fe04fc9a4..65b965ca40ea 100644 --- a/net/netfilter/xt_mark.c +++ b/net/netfilter/xt_mark.c @@ -62,7 +62,7 @@ static struct xt_target mark_tg_reg[] __read_mostly = { { .name = "MARK", .revision = 2, - .family = NFPROTO_IPV4, + .family = NFPROTO_IPV6, .target = mark_tg, .targetsize = sizeof(struct xt_mark_tginfo2), .me = THIS_MODULE, -- cgit v1.2.3