From 2230f5e2d75114d452bdd9c7b93bf8b8911fac95 Mon Sep 17 00:00:00 2001 From: Florian Westphal Date: Fri, 11 Jan 2019 14:46:15 +0100 Subject: netfilter: physdev: relax br_netfilter dependency [ Upstream commit 8e2f311a68494a6677c1724bdcb10bada21af37c ] Following command: iptables -D FORWARD -m physdev ... causes connectivity loss in some setups. Reason is that iptables userspace will probe kernel for the module revision of the physdev patch, and physdev has an artificial dependency on br_netfilter (xt_physdev use makes no sense unless a br_netfilter module is loaded). This causes the "phydev" module to be loaded, which in turn enables the "call-iptables" infrastructure. bridged packets might then get dropped by the iptables ruleset. The better fix would be to change the "call-iptables" defaults to 0 and enforce explicit setting to 1, but that breaks backwards compatibility. This does the next best thing: add a request_module call to checkentry. This was a stray '-D ... -m physdev' won't activate br_netfilter anymore. Signed-off-by: Florian Westphal Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin --- net/netfilter/xt_physdev.c | 9 +++++++-- 1 file changed, 7 insertions(+), 2 deletions(-) (limited to 'net/netfilter') diff --git a/net/netfilter/xt_physdev.c b/net/netfilter/xt_physdev.c index bb33598e4530..ec247d8370e8 100644 --- a/net/netfilter/xt_physdev.c +++ b/net/netfilter/xt_physdev.c @@ -96,8 +96,7 @@ match_outdev: static int physdev_mt_check(const struct xt_mtchk_param *par) { const struct xt_physdev_info *info = par->matchinfo; - - br_netfilter_enable(); + static bool brnf_probed __read_mostly; if (!(info->bitmask & XT_PHYSDEV_OP_MASK) || info->bitmask & ~XT_PHYSDEV_OP_MASK) @@ -113,6 +112,12 @@ static int physdev_mt_check(const struct xt_mtchk_param *par) if (par->hook_mask & (1 << NF_INET_LOCAL_OUT)) return -EINVAL; } + + if (!brnf_probed) { + brnf_probed = true; + request_module("br_netfilter"); + } + return 0; } -- cgit v1.2.3