linux.git/net/netfilter, branch v4.19-rc4

Merge git://git.kernel.org/pub/scm/linux/kernel/git/pablo/nf

2018-09-12T04:17:30+00:00

Pablo Neira Ayuso says:

====================
Netfilter fixes for net

The following patchset contains Netfilter fixes for you net tree:

1) Remove duplicated include at the end of UDP conntrack, from Yue Haibing.

2) Restore conntrack dependency on xt_cluster, from Martin Willi.

3) Fix splat with GSO skbs from the checksum target, from Florian Westphal.

4) Rework ct timeout support, the template strategy to attach custom timeouts
   is not correct since it will not work in conjunction with conntrack zones
   and we have a possible free after use when removing the rule due to missing
   refcounting. To fix these problems, do not use conntrack template at all
   and set custom timeout on the already valid conntrack object. This
   fix comes with a preparation patch to simplify timeout adjustment by
   initializating the first position of the timeout array for all of the
   existing trackers. Patchset from Florian Westphal.

5) Fix missing dependency on from IPv4 chain NAT type, from Florian.

6) Release chain reference counter from the flush path, from Taehee Yoo.

7) After flushing an iptables ruleset, conntrack hooks are unregistered
   and entries are left stale to be cleaned up by the timeout garbage
   collector. No TCP tracking is done on established flows by this time.
   If ruleset is reloaded, then hooks are registered again and TCP
   tracking is restored, which considers packets to be invalid. Clear
   window tracking to exercise TCP flow pickup from the middle given that
   history is lost for us. Again from Florian.

8) Fix crash from netlink interface with CONFIG_NF_CONNTRACK_TIMEOUT=y
   and CONFIG_NF_CT_NETLINK_TIMEOUT=n.

9) Broken CT target due to returning incorrect type from
   ctnl_timeout_find_get().

10) Solve conntrack clash on NF_REPEAT verdicts too, from Michal Vaner.

11) Missing conversion of hashlimit sysctl interface to new API, from
    Cong Wang.
====================

Signed-off-by: David S. Miller

netfilter: xt_hashlimit: use s->file instead of s->private

2018-09-10T23:35:32+00:00

After switching to the new procfs API, it is supposed to
retrieve the private pointer from PDE_DATA(file_inode(s->file)),
s->private is no longer referred.

Fixes: 1cd671827290 ("netfilter/x_tables: switch to proc_create_seq_private")
Reported-by: Sami Farin 
Signed-off-by: Cong Wang 
Acked-by: Christoph Hellwig 
Tested-by: Sami Farin 
Signed-off-by: Pablo Neira Ayuso

netfilter: nfnetlink_queue: Solve the NFQUEUE/conntrack clash for NF_REPEAT

2018-09-10T23:31:47+00:00

NF_REPEAT places the packet at the beginning of the iptables chain
instead of accepting or rejecting it right away. The packet however will
reach the end of the chain and continue to the end of iptables
eventually, so it needs the same handling as NF_ACCEPT and NF_DROP.

Fixes: 368982cd7d1b ("netfilter: nfnetlink_queue: resolve clash for unconfirmed conntracks")
Signed-off-by: Michal 'vorner' Vaner 
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: conntrack: timeout interface depend on CONFIG_NF_CONNTRACK_TIMEOUT

2018-09-10T23:30:25+00:00

Now that cttimeout support for nft_ct is in place, these should depend
on CONFIG_NF_CONNTRACK_TIMEOUT otherwise we can crash when dumping the
policy if this option is not enabled.

[   71.600121] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
[...]
[   71.600141] CPU: 3 PID: 7612 Comm: nft Not tainted 4.18.0+ #246
[...]
[   71.600188] Call Trace:
[   71.600201]  ? nft_ct_timeout_obj_dump+0xc6/0xf0 [nft_ct]

Signed-off-by: Pablo Neira Ayuso

netfilter: conntrack: reset tcp maxwin on re-register

2018-09-10T23:29:24+00:00

Doug Smythies says:
  Sometimes it is desirable to temporarily disable, or clear,
  the iptables rule set on a computer being controlled via a
  secure shell session (SSH). While unwise on an internet facing
  computer, I also do it often on non-internet accessible computers
  while testing. Recently, this has become problematic, with the
  SSH session being dropped upon re-load of the rule set.

The problem is that when all rules are deleted, conntrack hooks get
unregistered.

In case the rules are re-added later, its possible that tcp window
has moved far enough so that all packets are considered invalid (out of
window) until entry expires (which can take forever, default
established timeout is 5 days).

Fix this by clearing maxwin of existing tcp connections on register.

v2: don't touch entries on hook removal.
v3: remove obsolete expiry check.

Reported-by: Doug Smythies 
Fixes: 4d3a57f23dec59 ("netfilter: conntrack: do not enable connection tracking unless needed")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: release chain in flushing set

2018-08-31T17:07:11+00:00

When element of verdict map is deleted, the delete routine should
release chain. however, flush element of verdict map routine doesn't
release chain.

test commands:
   %nft add table ip filter
   %nft add chain ip filter c1
   %nft add map ip filter map1 { type ipv4_addr : verdict \; }
   %nft add element ip filter map1 { 1 : jump c1 }
   %nft flush map ip filter map1
   %nft flush ruleset

splat looks like:
[ 4895.170899] kernel BUG at net/netfilter/nf_tables_api.c:1415!
[ 4895.178114] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI
[ 4895.178880] CPU: 0 PID: 1670 Comm: nft Not tainted 4.18.0+ #55
[ 4895.178880] RIP: 0010:nf_tables_chain_destroy.isra.28+0x39/0x220 [nf_tables]
[ 4895.178880] Code: fc ff df 53 48 89 fb 48 83 c7 50 48 89 fa 48 c1 ea 03 0f b6 04 02 84 c0 74 09 3c 03 7f 05 e8 3e 4c 25 e1 8b 43 50 85 c0 74 02 <0f> 0b 48 89 da 48 b8 00 00 00 00 00 fc ff df 48 c1 ea 03 80 3c 02
[ 4895.228342] RSP: 0018:ffff88010b98f4c0 EFLAGS: 00010202
[ 4895.234841] RAX: 0000000000000001 RBX: ffff8801131c6968 RCX: ffff8801146585b0
[ 4895.234841] RDX: 1ffff10022638d37 RSI: ffff8801191a9348 RDI: ffff8801131c69b8
[ 4895.234841] RBP: ffff8801146585a8 R08: 1ffff1002323526a R09: 0000000000000000
[ 4895.234841] R10: 0000000000000000 R11: 0000000000000000 R12: dead000000000200
[ 4895.234841] R13: dead000000000100 R14: ffffffffa3638af8 R15: dffffc0000000000
[ 4895.234841] FS:  00007f6d188e6700(0000) GS:ffff88011b600000(0000) knlGS:0000000000000000
[ 4895.234841] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4895.234841] CR2: 00007ffe72b8df88 CR3: 000000010e2d4000 CR4: 00000000001006f0
[ 4895.234841] Call Trace:
[ 4895.234841]  nf_tables_commit+0x2704/0x2c70 [nf_tables]
[ 4895.234841]  ? nfnetlink_rcv_batch+0xa4f/0x11b0 [nfnetlink]
[ 4895.234841]  ? nf_tables_setelem_notify.constprop.48+0x1a0/0x1a0 [nf_tables]
[ 4895.323824]  ? __lock_is_held+0x9d/0x130
[ 4895.323824]  ? kasan_unpoison_shadow+0x30/0x40
[ 4895.333299]  ? kasan_kmalloc+0xa9/0xc0
[ 4895.333299]  ? kmem_cache_alloc_trace+0x2c0/0x310
[ 4895.333299]  ? nfnetlink_rcv_batch+0xa4f/0x11b0 [nfnetlink]
[ 4895.333299]  nfnetlink_rcv_batch+0xdb9/0x11b0 [nfnetlink]
[ 4895.333299]  ? debug_show_all_locks+0x290/0x290
[ 4895.333299]  ? nfnetlink_net_init+0x150/0x150 [nfnetlink]
[ 4895.333299]  ? sched_clock_cpu+0xe5/0x170
[ 4895.333299]  ? sched_clock_local+0xff/0x130
[ 4895.333299]  ? sched_clock_cpu+0xe5/0x170
[ 4895.333299]  ? find_held_lock+0x39/0x1b0
[ 4895.333299]  ? sched_clock_local+0xff/0x130
[ 4895.333299]  ? memset+0x1f/0x40
[ 4895.333299]  ? nla_parse+0x33/0x260
[ 4895.333299]  ? ns_capable_common+0x6e/0x110
[ 4895.333299]  nfnetlink_rcv+0x2c0/0x310 [nfnetlink]
[ ... ]

Fixes: 591054469b3e ("netfilter: nf_tables: revisit chain/object refcounting from elements")
Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_tables: rework ct timeout set support

2018-08-29T11:04:38+00:00

Using a private template is problematic:

1. We can't assign both a zone and a timeout policy
   (zone assigns a conntrack template, so we hit problem 1)
2. Using a template needs to take care of ct refcount, else we'll
   eventually free the private template due to ->use underflow.

This patch reworks template policy to instead work with existing conntrack.

As long as such conntrack has not yet been placed into the hash table
(unconfirmed) we can still add the timeout extension.

The only caveat is that we now need to update/correct ct->timeout to
reflect the initial/new state, otherwise the conntrack entry retains the
default 'new' timeout.

Side effect of this change is that setting the policy must
now occur from chains that are evaluated *after* the conntrack lookup
has taken place.

No released kernel contains the timeout policy feature yet, so this change
should be ok.

Changes since v2:
 - don't handle 'ct is confirmed case'
 - after previous patch, no need to special-case tcp/dccp/sctp timeout
   anymore

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

netfilter: conntrack: place 'new' timeout in first location too

2018-08-29T11:04:38+00:00

tcp, sctp and dccp trackers re-use the userspace ctnetlink states
to index their timeout arrays, which means timeout[0] is never
used.  Copy the 'new' state (syn-sent, dccp-request, ..) to 0 as well
so external users can simply read it off timeouts[0] without need to
differentiate dccp/sctp/tcp and udp/icmp/gre/generic.

The alternative is to map all array accesses to 'i - 1', but that
is a much more intrusive change.

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

netfilter: xt_checksum: ignore gso skbs

2018-08-24T07:58:16+00:00

Satish Patel reports a skb_warn_bad_offload() splat caused
by -j CHECKSUM rules:

-A POSTROUTING -p tcp -m tcp --sport 80 -j CHECKSUM

The CHECKSUM target has never worked with GSO skbs, and the above rule
makes no sense as kernel will handle checksum updates on transmit.

Unfortunately, there are 3rd party tools that install such rules, so we
cannot reject this from the config plane without potential breakage.

Amend Kconfig text to clarify that the CHECKSUM target is only useful
in virtualized environments, where old dhcp clients that use AF_PACKET
used to discard UDP packets with a 'bad' header checksum and add a
one-time warning in case such rule isn't restricted to UDP.

v2: check IP6T_F_PROTO flag before cmp (Michal Kubecek)

Reported-by: Satish Patel 
Reported-by: Markos Chandras 
Reported-by: Michal Kubecek 
Signed-off-by: Florian Westphal 
Reviewed-by: Michal Kubecek 
Signed-off-by: Pablo Neira Ayuso