linux.git/net/netfilter/nfnetlink_cttimeout.c, branch v5.0

netfilter: nfnetlink_cttimeout: fetch timeouts for udplite and gre, too

2018-11-26T09:25:20+00:00

syzbot was able to trigger the WARN in cttimeout_default_get() by
passing UDPLITE as l4protocol.  Alias UDPLITE to UDP, both use
same timeout values.

Furthermore, also fetch GRE timeouts.  GRE is a bit more complicated,
as it still can be a module and its netns_proto_gre struct layout isn't
visible outside of the gre module. Can't move timeouts around, it
appears conntrack sysctl unregister assumes net_generic() returns
nf_proto_net, so we get crash. Expose layout of netns_proto_gre instead.

A followup nf-next patch could make gre tracker be built-in as well
if needed, its not that large.

Last, make the WARN() mention the missing protocol value in case
anything else is missing.

Reported-by: syzbot+2fae8fa157dd92618cae@syzkaller.appspotmail.com
Fixes: 8866df9264a3 ("netfilter: nfnetlink_cttimeout: pass default timeout policy to obj_to_nlattr")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_cttimeout: pass default timeout policy to obj_to_nlattr

2018-11-03T12:28:03+00:00

Otherwise, we hit a NULL pointer deference since handlers always assume
default timeout policy is passed.

  netlink: 24 bytes leftover after parsing attributes in process `syz-executor2'.
  kasan: CONFIG_KASAN_INLINE enabled
  kasan: GPF could be caused by NULL-ptr deref or user memory access
  general protection fault: 0000 [#1] PREEMPT SMP KASAN
  CPU: 0 PID: 9575 Comm: syz-executor1 Not tainted 4.19.0+ #312
  Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
  RIP: 0010:icmp_timeout_obj_to_nlattr+0x77/0x170 net/netfilter/nf_conntrack_proto_icmp.c:297

Fixes: c779e849608a ("netfilter: conntrack: remove get_timeout() indirection")
Reported-by: Eric Dumazet 
Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: remove set but not used variable 'l3num'

2018-10-16T08:01:48+00:00

Fixes gcc '-Wunused-but-set-variable' warning:

net/netfilter/nfnetlink_cttimeout.c: In function 'cttimeout_default_set':
net/netfilter/nfnetlink_cttimeout.c:353:8: warning:
 variable 'l3num' set but not used [-Wunused-but-set-variable]

It not used any more after
commit dd2934a95701 ("netfilter: conntrack: remove l3->l4 mapping information")

Signed-off-by: YueHaibing 
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: remove l3->l4 mapping information

2018-09-20T16:07:35+00:00

l4 protocols are demuxed by l3num, l4num pair.

However, almost all l4 trackers are l3 agnostic.

Only exceptions are:
 - gre, icmp (ipv4 only)
 - icmpv6 (ipv6 only)

This commit gets rid of the l3 mapping, l4 trackers can now be looked up
by their IPPROTO_XXX value alone, which gets rid of the additional l3
indirection.

For icmp, ipcmp6 and gre, add a check on state->pf and
return -NF_ACCEPT in case we're asked to track e.g. icmpv6-in-ipv4,
this seems more fitting than using the generic tracker.

Additionally we can kill the 2nd l4proto definitions that were needed
for v4/v6 split -- they are now the same so we can use single l4proto
struct for each protocol, rather than two.

The EXPORT_SYMBOLs can be removed as all these object files are
part of nf_conntrack with no external references.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: remove superfluous check on layer 4 netlink functions

2018-09-17T14:11:14+00:00

We assume they are always set accordingly since a874752a10da
("netfilter: conntrack: timeout interface depend on
CONFIG_NF_CONNTRACK_TIMEOUT"), so we can get rid of this checks.

Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: ctnl_timeout_find_get() returns incorrect pointer to type

2018-09-10T23:31:10+00:00

Compiler did not catch incorrect typing in the rcu hook assignment.

 % nfct add timeout test-tcp inet tcp established 100 close 10 close_wait 10
 % iptables -I OUTPUT -t raw -p tcp -j CT --timeout test-tcp
 dmesg - xt_CT: Timeout policy `test-tcp' can only be used by L3 protocol number 25000

The CT target bails out with incorrect layer 3 protocol number.

Fixes: 6c1fd7dc489d ("netfilter: cttimeout: decouple timeout policy from nfnetlink_cttimeout object")
Reported-by: Harsha Sharma 
Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: decouple timeout policy from nfnetlink_cttimeout object

2018-08-07T15:14:15+00:00

The timeout policy is currently embedded into the nfnetlink_cttimeout
object, move the policy into an independent object. This allows us to
reuse part of the existing conntrack timeout extension from nf_tables
without adding dependencies with the nfnetlink_cttimeout object layout.

Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: move ctnl_untimeout to nf_conntrack

2018-08-07T15:14:10+00:00

As, ctnl_untimeout is required by nft_ct, so move ctnl_timeout from
nfnetlink_cttimeout to nf_conntrack_timeout and rename as nf_ct_timeout.

Signed-off-by: Harsha Sharma 
Signed-off-by: Pablo Neira Ayuso

netfilter: cttimeout: Make NF_CT_NETLINK_TIMEOUT depend on NF_CONNTRACK_TIMEOUT

2018-08-03T16:50:41+00:00

With this, remove ifdef for CONFIG_NF_CONNTRACK_TIMEOUT in
nfnetlink_cttimeout. This is also required for moving ctnl_untimeout
from nfnetlink_cttimeout to nf_conntrack_timeout.

Signed-off-by: Harsha Sharma 
Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: remove get_timeout() indirection

2018-07-16T15:55:01+00:00

Not needed, we can have the l4trackers fetch it themselvs.

Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso