diff options
| author | Florian Westphal <fw@strlen.de> | 2023-02-20 17:24:00 +0100 |
|---|---|---|
| committer | Pablo Neira Ayuso <pablo@netfilter.org> | 2023-02-22 00:28:47 +0100 |
| commit | fdf6491193e411087ae77bcbc6468e3e1cff99ed (patch) | |
| tree | fcf73502b337cbfe507b4c8480515fb30e82d6e2 /net/netfilter/nfnetlink.c | |
| parent | 05c07c0c6cc8ec2278ace9871618c41f1365d1f5 (diff) | |
| download | linux-fdf6491193e411087ae77bcbc6468e3e1cff99ed.tar.gz | |
netfilter: ctnetlink: make event listener tracking global
pernet tracking doesn't work correctly because other netns might have
set NETLINK_LISTEN_ALL_NSID on its event socket.
In this case its expected that events originating in other net
namespaces are also received.
Making pernet-tracking work while also honoring NETLINK_LISTEN_ALL_NSID
requires much more intrusive changes both in netlink and nfnetlink,
f.e. adding a 'setsockopt' callback that lets nfnetlink know that the
event socket entered (or left) ALL_NSID mode.
Move to global tracking instead: if there is an event socket anywhere
on the system, all net namespaces which have conntrack enabled and
use autobind mode will allocate the ecache extension.
netlink_has_listeners() returns false only if the given group has no
subscribers in any net namespace, the 'net' argument passed to
nfnetlink_has_listeners is only used to derive the protocol (nfnetlink),
it has no other effect.
For proper NETLINK_LISTEN_ALL_NSID-aware pernet tracking of event
listeners a new netlink_has_net_listeners() is also needed.
Fixes: 90d1daa45849 ("netfilter: conntrack: add nf_conntrack_events autodetect mode")
Reported-by: Bryce Kahle <bryce.kahle@datadoghq.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Diffstat (limited to 'net/netfilter/nfnetlink.c')
| -rw-r--r-- | net/netfilter/nfnetlink.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c index 6d18fb3468683..81c7737c803a6 100644 --- a/net/netfilter/nfnetlink.c +++ b/net/netfilter/nfnetlink.c @@ -29,6 +29,7 @@ #include <net/netlink.h> #include <net/netns/generic.h> +#include <linux/netfilter.h> #include <linux/netfilter/nfnetlink.h> MODULE_LICENSE("GPL"); @@ -685,12 +686,12 @@ static void nfnetlink_bind_event(struct net *net, unsigned int group) group_bit = (1 << group); spin_lock(&nfnl_grp_active_lock); - v = READ_ONCE(net->ct.ctnetlink_has_listener); + v = READ_ONCE(nf_ctnetlink_has_listener); if ((v & group_bit) == 0) { v |= group_bit; /* read concurrently without nfnl_grp_active_lock held. */ - WRITE_ONCE(net->ct.ctnetlink_has_listener, v); + WRITE_ONCE(nf_ctnetlink_has_listener, v); } spin_unlock(&nfnl_grp_active_lock); @@ -744,12 +745,12 @@ static void nfnetlink_unbind(struct net *net, int group) spin_lock(&nfnl_grp_active_lock); if (!nfnetlink_has_listeners(net, group)) { - u8 v = READ_ONCE(net->ct.ctnetlink_has_listener); + u8 v = READ_ONCE(nf_ctnetlink_has_listener); v &= ~group_bit; /* read concurrently without nfnl_grp_active_lock held. */ - WRITE_ONCE(net->ct.ctnetlink_has_listener, v); + WRITE_ONCE(nf_ctnetlink_has_listener, v); } spin_unlock(&nfnl_grp_active_lock); #endif |