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  1. 04 5月, 2019 2 次提交
  3. 02 5月, 2019 12 次提交
    • A
      ipvs: fix warning on unused variable · ae5e0c77
      由 Andrea Claudi 提交于 
      [ Upstream commit c93a49b9769e435990c82297aa0baa31e1538790 ]

When CONFIG_IP_VS_IPV6 is not defined, build produced this warning:

net/netfilter/ipvs/ip_vs_ctl.c:899:6: warning: unused variable ‘ret’ [-Wunused-variable]
  int ret = 0;
      ^~~

Fix this by moving the declaration of 'ret' in the CONFIG_IP_VS_IPV6
section in the same function.

While at it, drop its unneeded initialisation.

Fixes: 098e13f5b21d ("ipvs: fix dependency on nf_defrag_ipv6")
Reported-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NAndrea Claudi <aclaudi@redhat.com>
Reviewed-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      ae5e0c77
    • P
      netfilter: nf_tables: bogus EBUSY in helper removal from transaction · ffc1d85e
      由 Pablo Neira Ayuso 提交于 
      [ Upstream commit 8ffcd32f64633926163cdd07a7d295c500a947d1 ]

Proper use counter updates when activating and deactivating the object,
otherwise, this hits bogus EBUSY error.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: NLaura Garcia <nevola@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      ffc1d85e
    • P
      netfilter: nf_tables: bogus EBUSY when deleting set after flush · e313d5da
      由 Pablo Neira Ayuso 提交于 
      [ Upstream commit 273fe3f1006ea5ebc63d6729e43e8e45e32b256a ]

Set deletion after flush coming in the same batch results in EBUSY. Add
set use counter to track the number of references to this set from
rules. We cannot rely on the list of bindings for this since such list
is still populated from the preparation phase.
Reported-by: NVáclav Zindulka <vaclav.zindulka@tlapnet.cz>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e313d5da
    • P
      netfilter: nf_tables: fix set double-free in abort path · 25ddad73
      由 Pablo Neira Ayuso 提交于 
      [ Upstream commit 40ba1d9b4d19796afc9b7ece872f5f3e8f5e2c13 ]

The abort path can cause a double-free of an anonymous set.
Added-and-to-be-aborted rule looks like this:

udp dport { 137, 138 } drop

The to-be-aborted transaction list looks like this:

newset
newsetelem
newsetelem
rule

This gets walked in reverse order, so first pass disables the rule, the
set elements, then the set.

After synchronize_rcu(), we then destroy those in same order: rule, set
element, set element, newset.

Problem is that the anonymous set has already been bound to the rule, so
the rule (lookup expression destructor) already frees the set, when then
cause use-after-free when trying to delete the elements from this set,
then try to free the set again when handling the newset expression.

Rule releases the bound set in first place from the abort path, this
causes the use-after-free on set element removal when undoing the new
element transactions. To handle this, skip new element transaction if
set is bound from the abort path.

This is still causes the use-after-free on set element removal.  To
handle this, remove transaction from the list when the set is already
bound.

Joint work with Florian Westphal.

Fixes: f6ac85858976 ("netfilter: nf_tables: unbind set in rule from commit path")
Bugzilla: https://bugzilla.netfilter.org/show_bug.cgi?id=1325Acked-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      25ddad73
    • P
      netfilter: nft_compat: use .release_ops and remove list of extension · 8906234c
      由 Pablo Neira Ayuso 提交于 
      [ Upstream commit b8e204006340b7aaf32bd2b9806c692f6e0cb38a ]

Add .release_ops, that is called in case of error at a later stage in
the expression initialization path, ie. .select_ops() has been already
set up operations and that needs to be undone. This allows us to unwind
.select_ops from the error path, ie. release the dynamic operations for
this extension.

Moreover, allocate one single operation instead of recycling them, this
comes at the cost of consuming a bit more memory per rule, but it
simplifies the infrastructure.
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      8906234c
    • F
      netfilter: nft_compat: don't use refcount_inc on newly allocated entry · 4f67e897
      由 Florian Westphal 提交于 
      [ Upstream commit 947e492c0fc2132ae5fca081a9c2952ccaab0404 ]

When I moved the refcount to refcount_t type I missed the fact that
refcount_inc() will result in use-after-free warning with
CONFIG_REFCOUNT_FULL=y builds.

The correct fix would be to init the reference count to 1 at allocation
time, but, unfortunately we cannot do this, as we can't undo that
in case something else fails later in the batch.

So only solution I see is to special-case the 'new entry' condition
and replace refcount_inc() with a "delayed" refcount_set(1) in this case,
as done here.

The .activate callback can be removed to simplify things, we only
need to make sure that deactivate() decrements/unlinks the entry
from the list at end of transaction phase (commit or abort).

Fixes: 12c44aba6618 ("netfilter: nft_compat: use refcnt_t type for nft_xt reference count")
Reported-by: NJordan Glover <Golden_Miller83@protonmail.ch>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      4f67e897
    • P
      netfilter: nf_tables: unbind set in rule from commit path · af26f3e2
      由 Pablo Neira Ayuso 提交于 
      Anonymous sets that are bound to rules from the same transaction trigger
a kernel splat from the abort path due to double set list removal and
double free.

This patch updates the logic to search for the transaction that is
responsible for creating the set and disable the set list removal and
release, given the rule is now responsible for this. Lookup is reverse
since the transaction that adds the set is likely to be at the tail of
the list.

Moreover, this patch adds the unbind step to deliver the event from the
commit path.  This should not be done from the worker thread, since we
have no guarantees of in-order delivery to the listener.

This patch removes the assumption that both activate and deactivate
callbacks need to be provided.

Fixes: cd5125d8f518 ("netfilter: nf_tables: split set destruction in deactivate and destroy phase")
Reported-by: NMikhail Morfikov <mmorfikov@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      af26f3e2
    • F
      netfilter: nf_tables: warn when expr implements only one of activate/deactivate · 27458b54
      由 Florian Westphal 提交于 
      ->destroy is only allowed to free data, or do other cleanups that do not
have side effects on other state, such as visibility to other netlink
requests.

Such things need to be done in ->deactivate.
As a transaction can fail, we need to make sure we can undo such
operations, therefore ->activate() has to be provided too.

So print a warning and refuse registration if expr->ops provides
only one of the two operations.

v2: fix nft_expr_check_ops to not repeat same check twice (Jones Desougi)
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      27458b54
    • F
      netfilter: nft_compat: destroy function must not have side effects · cb2e343d
      由 Florian Westphal 提交于 
      The nft_compat destroy function deletes the nft_xt object from a list.
This isn't allowed anymore. Destroy functions are called asynchronously,
i.e. next batch can find the object that has a pending ->destroy()
invocation:

cpu0                       cpu1
 worker
   ->destroy               for_each_entry()
	                     if (x == ...
			        return x->ops;
     list_del(x)
     kfree_rcu(x)
                           expr->ops->... // ops was free'd

To resolve this, the list_del needs to occur before the transaction
mutex gets released.  nf_tables has a 'deactivate' hook for this
purpose, so use that to unlink the object from the list.

Fixes: 0935d5588400 ("netfilter: nf_tables: asynchronous release")
Reported-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
      cb2e343d
    • F
      netfilter: nf_tables: split set destruction in deactivate and destroy phase · 3dbba8eb
      由 Florian Westphal 提交于 
      [ Upstream commit cd5125d8f51882279f50506bb9c7e5e89dc9bef3 ]

Splits unbind_set into destroy_set and unbinding operation.

Unbinding removes set from lists (so new transaction would not
find it anymore) but keeps memory allocated (so packet path continues
to work).

Rebind function is added to allow unrolling in case transaction
that wants to remove set is aborted.

Destroy function is added to free the memory, but this could occur
outside of transaction in the future.
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      3dbba8eb
    • F
      netfilter: nft_compat: make lists per netns · 7693bae6
      由 Florian Westphal 提交于 
      [ Upstream commit cf52572ebbd7189a1966c2b5fc34b97078cd1dce ]

There are two problems with nft_compat since the netlink config
plane uses a per-netns mutex:

1. Concurrent add/del accesses to the same list
2. accesses to a list element after it has been free'd already.

This patch fixes the first problem.

Freeing occurs from a work queue, after transaction mutexes have been
released, i.e., it still possible for a new transaction (even from
same net ns) to find the to-be-deleted expression in the list.

The ->destroy functions are not allowed to have any such side effects,
i.e. the list_del() in the destroy function is not allowed.

This part of the problem is solved in the next patch.
I tried to make this work by serializing list access via mutex
and by moving list_del() to a deactivate callback, but
Taehee spotted following race on this approach:

  NET #0                          NET #1
   >select_ops()
   ->init()
                                   ->select_ops()
   ->deactivate()
   ->destroy()
      nft_xt_put()
       kfree_rcu(xt, rcu_head);
                                   ->init() <-- use-after-free occurred.

Unfortunately, we can't increment reference count in
select_ops(), because we can't undo the refcount increase in
case a different expression fails in the same batch.

(The destroy hook will only be called in case the expression
 was initialized successfully).

Fixes: f102d66b ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Reported-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      7693bae6
    • F
      netfilter: nft_compat: use refcnt_t type for nft_xt reference count · db99f122
      由 Florian Westphal 提交于 
      [ Upstream commit 12c44aba6618b7f6c437076e5722237190f6cd5f ]

Using standard integer type was fine while all operations on it were
guarded by the nftnl subsys mutex.

This isn't true anymore:
1. transactions are guarded only by a pernet mutex, so concurrent
   rule manipulation in different netns is racy
2. the ->destroy hook runs from a work queue after the transaction
   mutex has been released already.

cpu0                           cpu1 (net 1)        cpu2 (net 2)
 kworker
    nft_compat->destroy        nft_compat->init    nft_compat->init
      if (--nft_xt->ref == 0)   nft_xt->ref++        nft_xt->ref++

Switch to refcount_t.  Doing this however only fixes a minor aspect,
nft_compat also performs linked-list operations in an unsafe way.

This is addressed in the next two patches.

Fixes: f102d66b ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Fixes: 0935d5588400 ("netfilter: nf_tables: asynchronous release")
Reported-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      db99f122
  5. 20 4月, 2019 2 次提交
    • T
      netfilter: nf_flow_table: remove flowtable hook flush routine in netns exit routine · 263ed7e6
      由 Taehee Yoo 提交于 
      [ Upstream commit b7f1a16d29b2e28d3dcbb070511bd703e306281b ]

When device is unregistered, flowtable flush routine is called
by notifier_call(nf_tables_flowtable_event). and exit callback of
nftables pernet_operation(nf_tables_exit_net) also has flowtable flush
routine. but when network namespace is destroyed, both notifier_call
and pernet_operation are called. hence flowtable flush routine in
pernet_operation is unnecessary.

test commands:
   %ip netns add vm1
   %ip netns exec vm1 nft add table ip filter
   %ip netns exec vm1 nft add flowtable ip filter w \
	{ hook ingress priority 0\; devices = { lo }\; }
   %ip netns del vm1

splat looks like:
[  265.187019] WARNING: CPU: 0 PID: 87 at net/netfilter/core.c:309 nf_hook_entry_head+0xc7/0xf0
[  265.187112] Modules linked in: nf_flow_table_ipv4 nf_flow_table nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 nf_tables nfnetlink ip_tables x_tables
[  265.187390] CPU: 0 PID: 87 Comm: kworker/u4:2 Not tainted 4.19.0-rc3+ #5
[  265.187453] Workqueue: netns cleanup_net
[  265.187514] RIP: 0010:nf_hook_entry_head+0xc7/0xf0
[  265.187546] Code: 8d 81 68 03 00 00 5b c3 89 d0 83 fa 04 48 8d 84 c7 e8 11 00 00 76 81 0f 0b 31 c0 e9 78 ff ff ff 0f 0b 48 83 c4 08 31 c0 5b c3 <0f> 0b 31 c0 e9 65 ff ff ff 0f 0b 31 c0 e9 5c ff ff ff 48 89 0c 24
[  265.187573] RSP: 0018:ffff88011546f098 EFLAGS: 00010246
[  265.187624] RAX: ffffffff8d90e135 RBX: 1ffff10022a8de1c RCX: 0000000000000000
[  265.187645] RDX: 0000000000000000 RSI: 0000000000000005 RDI: ffff880116298040
[  265.187645] RBP: ffff88010ea4c1a8 R08: 0000000000000000 R09: 0000000000000000
[  265.187645] R10: ffff88011546f1d8 R11: ffffed0022c532c1 R12: ffff88010ea4c1d0
[  265.187645] R13: 0000000000000005 R14: dffffc0000000000 R15: ffff88010ea4c1c4
[  265.187645] FS:  0000000000000000(0000) GS:ffff88011b200000(0000) knlGS:0000000000000000
[  265.187645] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  265.187645] CR2: 00007fdfb8d00000 CR3: 0000000057a16000 CR4: 00000000001006f0
[  265.187645] Call Trace:
[  265.187645]  __nf_unregister_net_hook+0xca/0x5d0
[  265.187645]  ? nf_hook_entries_free.part.3+0x80/0x80
[  265.187645]  ? save_trace+0x300/0x300
[  265.187645]  nf_unregister_net_hooks+0x2e/0x40
[  265.187645]  nf_tables_exit_net+0x479/0x1340 [nf_tables]
[  265.187645]  ? find_held_lock+0x39/0x1c0
[  265.187645]  ? nf_tables_abort+0x30/0x30 [nf_tables]
[  265.187645]  ? inet_frag_destroy_rcu+0xd0/0xd0
[  265.187645]  ? trace_hardirqs_on+0x93/0x210
[  265.187645]  ? __bpf_trace_preemptirq_template+0x10/0x10
[  265.187645]  ? inet_frag_destroy_rcu+0xd0/0xd0
[  265.187645]  ? inet_frag_destroy_rcu+0xd0/0xd0
[  265.187645]  ? __mutex_unlock_slowpath+0x17f/0x740
[  265.187645]  ? wait_for_completion+0x710/0x710
[  265.187645]  ? bucket_table_free+0xb2/0x1f0
[  265.187645]  ? nested_table_free+0x130/0x130
[  265.187645]  ? __lock_is_held+0xb4/0x140
[  265.187645]  ops_exit_list.isra.10+0x94/0x140
[  265.187645]  cleanup_net+0x45b/0x900
[ ... ]

This WARNING means that hook unregisteration is failed because
all flowtables hooks are already unregistered by notifier_call.

Network namespace exit routine guarantees that all devices will be
unregistered first. then, other exit callbacks of pernet_operations
are called. so that removing flowtable flush routine in exit callback of
pernet_operation(nf_tables_exit_net) doesn't make flowtable leak.
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      263ed7e6
    • P
      netfilter: xt_cgroup: shrink size of v2 path · 1f2b1c6a
      由 Pablo Neira Ayuso 提交于 
      [ Upstream commit 0d704967f4a49cc2212350b3e4a8231f8b4283ed ]

cgroup v2 path field is PATH_MAX which is too large, this is placing too
much pressure on memory allocation for people with many rules doing
cgroup v1 classid matching, side effects of this are bug reports like:

https://bugzilla.kernel.org/show_bug.cgi?id=200639

This patch registers a new revision that shrinks the cgroup path to 512
bytes, which is the same approach we follow in similar extensions that
have a path field.

Cc: Tejun Heo <tj@kernel.org>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Acked-by: NTejun Heo <tj@kernel.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      1f2b1c6a
  7. 17 4月, 2019 2 次提交
  9. 06 4月, 2019 4 次提交
    • F
      netfilter: physdev: relax br_netfilter dependency · 2e6bcc32
      由 Florian Westphal 提交于 
      [ 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: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      2e6bcc32
    • C
      netfilter: conntrack: fix cloned unconfirmed skb->_nfct race in __nf_conntrack_confirm · 3a1ce979
      由 Chieh-Min Wang 提交于 
      [ Upstream commit 13f5251fd17088170c18844534682d9cab5ff5aa ]

For bridge(br_flood) or broadcast/multicast packets, they could clone
skb with unconfirmed conntrack which break the rule that unconfirmed
skb->_nfct is never shared.  With nfqueue running on my system, the race
can be easily reproduced with following warning calltrace:

[13257.707525] CPU: 0 PID: 12132 Comm: main Tainted: P        W       4.4.60 #7744
[13257.707568] Hardware name: Qualcomm (Flattened Device Tree)
[13257.714700] [<c021f6dc>] (unwind_backtrace) from [<c021bce8>] (show_stack+0x10/0x14)
[13257.720253] [<c021bce8>] (show_stack) from [<c0449e10>] (dump_stack+0x94/0xa8)
[13257.728240] [<c0449e10>] (dump_stack) from [<c022a7e0>] (warn_slowpath_common+0x94/0xb0)
[13257.735268] [<c022a7e0>] (warn_slowpath_common) from [<c022a898>] (warn_slowpath_null+0x1c/0x24)
[13257.743519] [<c022a898>] (warn_slowpath_null) from [<c06ee450>] (__nf_conntrack_confirm+0xa8/0x618)
[13257.752284] [<c06ee450>] (__nf_conntrack_confirm) from [<c0772670>] (ipv4_confirm+0xb8/0xfc)
[13257.761049] [<c0772670>] (ipv4_confirm) from [<c06e7a60>] (nf_iterate+0x48/0xa8)
[13257.769725] [<c06e7a60>] (nf_iterate) from [<c06e7af0>] (nf_hook_slow+0x30/0xb0)
[13257.777108] [<c06e7af0>] (nf_hook_slow) from [<c07f20b4>] (br_nf_post_routing+0x274/0x31c)
[13257.784486] [<c07f20b4>] (br_nf_post_routing) from [<c06e7a60>] (nf_iterate+0x48/0xa8)
[13257.792556] [<c06e7a60>] (nf_iterate) from [<c06e7af0>] (nf_hook_slow+0x30/0xb0)
[13257.800458] [<c06e7af0>] (nf_hook_slow) from [<c07e5580>] (br_forward_finish+0x94/0xa4)
[13257.808010] [<c07e5580>] (br_forward_finish) from [<c07f22ac>] (br_nf_forward_finish+0x150/0x1ac)
[13257.815736] [<c07f22ac>] (br_nf_forward_finish) from [<c06e8df0>] (nf_reinject+0x108/0x170)
[13257.824762] [<c06e8df0>] (nf_reinject) from [<c06ea854>] (nfqnl_recv_verdict+0x3d8/0x420)
[13257.832924] [<c06ea854>] (nfqnl_recv_verdict) from [<c06e940c>] (nfnetlink_rcv_msg+0x158/0x248)
[13257.841256] [<c06e940c>] (nfnetlink_rcv_msg) from [<c06e5564>] (netlink_rcv_skb+0x54/0xb0)
[13257.849762] [<c06e5564>] (netlink_rcv_skb) from [<c06e4ec8>] (netlink_unicast+0x148/0x23c)
[13257.858093] [<c06e4ec8>] (netlink_unicast) from [<c06e5364>] (netlink_sendmsg+0x2ec/0x368)
[13257.866348] [<c06e5364>] (netlink_sendmsg) from [<c069fb8c>] (sock_sendmsg+0x34/0x44)
[13257.874590] [<c069fb8c>] (sock_sendmsg) from [<c06a03dc>] (___sys_sendmsg+0x1ec/0x200)
[13257.882489] [<c06a03dc>] (___sys_sendmsg) from [<c06a11c8>] (__sys_sendmsg+0x3c/0x64)
[13257.890300] [<c06a11c8>] (__sys_sendmsg) from [<c0209b40>] (ret_fast_syscall+0x0/0x34)

The original code just triggered the warning but do nothing. It will
caused the shared conntrack moves to the dying list and the packet be
droppped (nf_ct_resolve_clash returns NF_DROP for dying conntrack).

- Reproduce steps:

+----------------------------+
|          br0(bridge)       |
|                            |
+-+---------+---------+------+
  | eth0|   | eth1|   | eth2|
  |     |   |     |   |     |
  +--+--+   +--+--+   +---+-+
     |         |          |
     |         |          |
  +--+-+     +-+--+    +--+-+
  | PC1|     | PC2|    | PC3|
  +----+     +----+    +----+

iptables -A FORWARD -m mark --mark 0x1000000/0x1000000 -j NFQUEUE --queue-num 100 --queue-bypass

ps: Our nfq userspace program will set mark on packets whose connection
has already been processed.

PC1 sends broadcast packets simulated by hping3:

hping3 --rand-source --udp 192.168.1.255 -i u100

- Broadcast racing flow chart is as follow:

br_handle_frame
  BR_HOOK(NFPROTO_BRIDGE, NF_BR_PRE_ROUTING, br_handle_frame_finish)
  // skb->_nfct (unconfirmed conntrack) is constructed at PRE_ROUTING stage
  br_handle_frame_finish
    // check if this packet is broadcast
    br_flood_forward
      br_flood
        list_for_each_entry_rcu(p, &br->port_list, list) // iterate through each port
          maybe_deliver
            deliver_clone
              skb = skb_clone(skb)
              __br_forward
                BR_HOOK(NFPROTO_BRIDGE, NF_BR_FORWARD,...)
                // queue in our nfq and received by our userspace program
                // goto __nf_conntrack_confirm with process context on CPU 1
    br_pass_frame_up
      BR_HOOK(NFPROTO_BRIDGE, NF_BR_LOCAL_IN,...)
      // goto __nf_conntrack_confirm with softirq context on CPU 0

Because conntrack confirm can happen at both INPUT and POSTROUTING
stage.  So with NFQUEUE running, skb->_nfct with the same unconfirmed
conntrack could race on different core.

This patch fixes a repeating kernel splat, now it is only displayed
once.
Signed-off-by: NChieh-Min Wang <chiehminw@synology.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      3a1ce979
    • F
      netfilter: conntrack: tcp: only close if RST matches exact sequence · ca66f667
      由 Florian Westphal 提交于 
      [ Upstream commit be0502a3f2e94211a8809a09ecbc3a017189b8fb ]

TCP resets cause instant transition from established to closed state
provided the reset is in-window.  Endpoints that implement RFC 5961
require resets to match the next expected sequence number.
RST segments that are in-window (but that do not match RCV.NXT) are
ignored, and a "challenge ACK" is sent back.

Main problem for conntrack is that its a middlebox, i.e.  whereas an end
host might have ACK'd SEQ (and would thus accept an RST with this
sequence number), conntrack might not have seen this ACK (yet).

Therefore we can't simply flag RSTs with non-exact match as invalid.

This updates RST processing as follows:

1. If the connection is in a state other than ESTABLISHED, nothing is
   changed, RST is subject to normal in-window check.

2. If the RSTs sequence number either matches exactly RCV.NXT,
   connection state moves to CLOSE.

3. The same applies if the RST sequence number aligns with a previous
   packet in the same direction.

In all other cases, the connection remains in ESTABLISHED state.
If the normal-in-window check passes, the timeout will be lowered
to that of CLOSE.

If the peer sends a challenge ack, connection timeout will be reset.

If the challenge ACK triggers another RST (RST was valid after all),
this 2nd RST will match expected sequence and conntrack state changes to
CLOSE.

If no challenge ACK is received, the connection will time out after
CLOSE seconds (10 seconds by default), just like without this patch.

Packetdrill test case:

0.000 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
0.000 setsockopt(3, SOL_SOCKET, SO_REUSEADDR, [1], 4) = 0
0.000 bind(3, ..., ...) = 0
0.000 listen(3, 1) = 0

0.100 < S 0:0(0) win 32792 <mss 1460,sackOK,nop,nop,nop,wscale 7>
0.100 > S. 0:0(0) ack 1 win 64240 <mss 1460,nop,nop,sackOK,nop,wscale 7>
0.200 < . 1:1(0) ack 1 win 257
0.200 accept(3, ..., ...) = 4

// Receive a segment.
0.210 < P. 1:1001(1000) ack 1 win 46
0.210 > . 1:1(0) ack 1001

// Application writes 1000 bytes.
0.250 write(4, ..., 1000) = 1000
0.250 > P. 1:1001(1000) ack 1001

// First reset, old sequence. Conntrack (correctly) considers this
// invalid due to failed window validation (regardless of this patch).
0.260 < R  2:2(0) ack 1001 win 260

// 2nd reset, but too far ahead sequence.  Same: correctly handled
// as invalid.
0.270 < R 99990001:99990001(0) ack 1001 win 260

// in-window, but not exact sequence.
// Current Linux kernels might reply with a challenge ack, and do not
// remove connection.
// Without this patch, conntrack state moves to CLOSE.
// With patch, timeout is lowered like CLOSE, but connection stays
// in ESTABLISHED state.
0.280 < R 1010:1010(0) ack 1001 win 260

// Expect challenge ACK
0.281 > . 1001:1001(0) ack 1001 win 501

// With or without this patch, RST will cause connection
// to move to CLOSE (sequence number matches)
// 0.282 < R 1001:1001(0) ack 1001 win 260

// ACK
0.300 < . 1001:1001(0) ack 1001 win 257

// more data could be exchanged here, connection
// is still established

// Client closes the connection.
0.610 < F. 1001:1001(0) ack 1001 win 260
0.650 > . 1001:1001(0) ack 1002

// Close the connection without reading outstanding data
0.700 close(4) = 0

// so one more reset.  Will be deemed acceptable with patch as well:
// connection is already closing.
0.701 > R. 1001:1001(0) ack 1002 win 501
// End packetdrill test case.

With patch, this generates following conntrack events:
   [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [UNREPLIED]
[UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80
[UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 120 FIN_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 60 CLOSE_WAIT src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]
[UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5437 dport=80 [ASSURED]

Without patch, first RST moves connection to close, whereas socket state
does not change until FIN is received.
   [NEW] 120 SYN_SENT src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [UNREPLIED]
[UPDATE] 60 SYN_RECV src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80
[UPDATE] 432000 ESTABLISHED src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED]
[UPDATE] 10 CLOSE src=10.0.2.1 dst=10.0.0.1 sport=5141 dport=80 [ASSURED]

Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      ca66f667
    • L
      netfilter: nf_tables: check the result of dereferencing base_chain->stats · 709aaa09
      由 Li RongQing 提交于 
      [ Upstream commit a9f5e78c403d2d62ade4f4c85040efc85f4049b8 ]

Check the result of dereferencing base_chain->stats, instead of result
of this_cpu_ptr with NULL.

base_chain->stats maybe be changed to NULL when a chain is updated and a
new NULL counter can be attached.

And we do not need to check returning of this_cpu_ptr since
base_chain->stats is from percpu allocator if it is non-NULL,
this_cpu_ptr returns a valid value.

And fix two sparse error by replacing rcu_access_pointer and
rcu_dereference with READ_ONCE under rcu_read_lock.

Thanks for Eric's help to finish this patch.

Fixes: 00924094 ("netfilter: nf_tables: don't assume chain stats are set when jumplabel is set")
Signed-off-by: NEric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: NZhang Yu <zhangyu31@baidu.com>
Signed-off-by: NLi RongQing <lirongqing@baidu.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      709aaa09
  11. 24 3月, 2019 2 次提交
    • A
      ipvs: fix dependency on nf_defrag_ipv6 · 5ca2ef67
      由 Andrea Claudi 提交于 
      [ Upstream commit 098e13f5b21d3398065fce8780f07a3ef62f4812 ]

ipvs relies on nf_defrag_ipv6 module to manage IPv6 fragmentation,
but lacks proper Kconfig dependencies and does not explicitly
request defrag features.

As a result, if netfilter hooks are not loaded, when IPv6 fragmented
packet are handled by ipvs only the first fragment makes through.

Fix it properly declaring the dependency on Kconfig and registering
netfilter hooks on ip_vs_add_service() and ip_vs_new_dest().
Reported-by: NLi Shuang <shuali@redhat.com>
Signed-off-by: NAndrea Claudi <aclaudi@redhat.com>
Acked-by: NJulian Anastasov <ja@ssi.bg>
Acked-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      5ca2ef67
    • F
      netfilter: compat: initialize all fields in xt_init · e0e6b0d7
      由 Francesco Ruggeri 提交于 
      [ Upstream commit 8d29d16d21342a0c86405d46de0c4ac5daf1760f ]

If a non zero value happens to be in xt[NFPROTO_BRIDGE].cur at init
time, the following panic can be caused by running

% ebtables -t broute -F BROUTING

from a 32-bit user level on a 64-bit kernel. This patch replaces
kmalloc_array with kcalloc when allocating xt.

[  474.680846] BUG: unable to handle kernel paging request at 0000000009600920
[  474.687869] PGD 2037006067 P4D 2037006067 PUD 2038938067 PMD 0
[  474.693838] Oops: 0000 [#1] SMP
[  474.697055] CPU: 9 PID: 4662 Comm: ebtables Kdump: loaded Not tainted 4.19.17-11302235.AroraKernelnext.fc18.x86_64 #1
[  474.707721] Hardware name: Supermicro X9DRT/X9DRT, BIOS 3.0 06/28/2013
[  474.714313] RIP: 0010:xt_compat_calc_jump+0x2f/0x63 [x_tables]
[  474.720201] Code: 40 0f b6 ff 55 31 c0 48 6b ff 70 48 03 3d dc 45 00 00 48 89 e5 8b 4f 6c 4c 8b 47 60 ff c9 39 c8 7f 2f 8d 14 08 d1 fa 48 63 fa <41> 39 34 f8 4c 8d 0c fd 00 00 00 00 73 05 8d 42 01 eb e1 76 05 8d
[  474.739023] RSP: 0018:ffffc9000943fc58 EFLAGS: 00010207
[  474.744296] RAX: 0000000000000000 RBX: ffffc90006465000 RCX: 0000000002580249
[  474.751485] RDX: 00000000012c0124 RSI: fffffffff7be17e9 RDI: 00000000012c0124
[  474.758670] RBP: ffffc9000943fc58 R08: 0000000000000000 R09: ffffffff8117cf8f
[  474.765855] R10: ffffc90006477000 R11: 0000000000000000 R12: 0000000000000001
[  474.773048] R13: 0000000000000000 R14: ffffc9000943fcb8 R15: ffffc9000943fcb8
[  474.780234] FS:  0000000000000000(0000) GS:ffff88a03f840000(0063) knlGS:00000000f7ac7700
[  474.788612] CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
[  474.794632] CR2: 0000000009600920 CR3: 0000002037422006 CR4: 00000000000606e0
[  474.802052] Call Trace:
[  474.804789]  compat_do_replace+0x1fb/0x2a3 [ebtables]
[  474.810105]  compat_do_ebt_set_ctl+0x69/0xe6 [ebtables]
[  474.815605]  ? try_module_get+0x37/0x42
[  474.819716]  compat_nf_setsockopt+0x4f/0x6d
[  474.824172]  compat_ip_setsockopt+0x7e/0x8c
[  474.828641]  compat_raw_setsockopt+0x16/0x3a
[  474.833220]  compat_sock_common_setsockopt+0x1d/0x24
[  474.838458]  __compat_sys_setsockopt+0x17e/0x1b1
[  474.843343]  ? __check_object_size+0x76/0x19a
[  474.847960]  __ia32_compat_sys_socketcall+0x1cb/0x25b
[  474.853276]  do_fast_syscall_32+0xaf/0xf6
[  474.857548]  entry_SYSENTER_compat+0x6b/0x7a
Signed-off-by: NFrancesco Ruggeri <fruggeri@arista.com>
Acked-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e0e6b0d7
  13. 14 3月, 2019 4 次提交
    • T
      netfilter: xt_TEE: add missing code to get interface index in checkentry. · e6e00017
      由 Taehee Yoo 提交于 
      [ Upstream commit 18c0ab87364ac5128a152055fdcb1d27e01caf01 ]

checkentry(tee_tg_check) should initialize priv->oif from dev if possible.
But only netdevice notifier handler can set that.
Hence priv->oif is always -1 until notifier handler is called.

Fixes: 9e2f6c5d ("netfilter: Rework xt_TEE netdevice notifier")
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e6e00017
    • T
      netfilter: xt_TEE: fix wrong interface selection · 02d86085
      由 Taehee Yoo 提交于 
      [ Upstream commit f24d2d4f9586985509320f90308723d3d0c4e47f ]

TEE netdevice notifier handler checks only interface name. however
each netns can have same interface name. hence other netns's interface
could be selected.

test commands:
   %ip netns add vm1
   %iptables -I INPUT -p icmp -j TEE --gateway 192.168.1.1 --oif enp2s0
   %ip link set enp2s0 netns vm1

Above rule is in the root netns. but that rule could get enp2s0
ifindex of vm1 by notifier handler.

After this patch, TEE rule is added to the per-netns list.

Fixes: 9e2f6c5d ("netfilter: Rework xt_TEE netdevice notifier")
Signed-off-by: NTaehee Yoo <ap420073@gmail.com>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      02d86085
    • M
      netfilter: nf_nat: skip nat clash resolution for same-origin entries · 5058447b
      由 Martynas Pumputis 提交于 
      [ Upstream commit 4e35c1cb9460240e983a01745b5f29fe3a4d8e39 ]

It is possible that two concurrent packets originating from the same
socket of a connection-less protocol (e.g. UDP) can end up having
different IP_CT_DIR_REPLY tuples which results in one of the packets
being dropped.

To illustrate this, consider the following simplified scenario:

1. Packet A and B are sent at the same time from two different threads
   by same UDP socket.  No matching conntrack entry exists yet.
   Both packets cause allocation of a new conntrack entry.
2. get_unique_tuple gets called for A.  No clashing entry found.
   conntrack entry for A is added to main conntrack table.
3. get_unique_tuple is called for B and will find that the reply
   tuple of B is already taken by A.
   It will allocate a new UDP source port for B to resolve the clash.
4. conntrack entry for B cannot be added to main conntrack table
   because its ORIGINAL direction is clashing with A and the REPLY
   directions of A and B are not the same anymore due to UDP source
   port reallocation done in step 3.

This patch modifies nf_conntrack_tuple_taken so it doesn't consider
colliding reply tuples if the IP_CT_DIR_ORIGINAL tuples are equal.

[ Florian: simplify patch to not use .allow_clash setting
  and always ignore identical flows ]
Signed-off-by: NMartynas Pumputis <martynas@weave.works>
Signed-off-by: NFlorian Westphal <fw@strlen.de>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      5058447b
    • Z
      ipvs: Fix signed integer overflow when setsockopt timeout · e0b03a6b
      由 ZhangXiaoxu 提交于 
      [ Upstream commit 53ab60baa1ac4f20b080a22c13b77b6373922fd7 ]

There is a UBSAN bug report as below:
UBSAN: Undefined behaviour in net/netfilter/ipvs/ip_vs_ctl.c:2227:21
signed integer overflow:
-2147483647 * 1000 cannot be represented in type 'int'

Reproduce program:
	#include <stdio.h>
	#include <sys/types.h>
	#include <sys/socket.h>

	#define IPPROTO_IP 0
	#define IPPROTO_RAW 255

	#define IP_VS_BASE_CTL		(64+1024+64)
	#define IP_VS_SO_SET_TIMEOUT	(IP_VS_BASE_CTL+10)

	/* The argument to IP_VS_SO_GET_TIMEOUT */
	struct ipvs_timeout_t {
		int tcp_timeout;
		int tcp_fin_timeout;
		int udp_timeout;
	};

	int main() {
		int ret = -1;
		int sockfd = -1;
		struct ipvs_timeout_t to;

		sockfd = socket(AF_INET, SOCK_RAW, IPPROTO_RAW);
		if (sockfd == -1) {
			printf("socket init error\n");
			return -1;
		}

		to.tcp_timeout = -2147483647;
		to.tcp_fin_timeout = -2147483647;
		to.udp_timeout = -2147483647;

		ret = setsockopt(sockfd,
				 IPPROTO_IP,
				 IP_VS_SO_SET_TIMEOUT,
				 (char *)(&to),
				 sizeof(to));

		printf("setsockopt return %d\n", ret);
		return ret;
	}

Return -EINVAL if the timeout value is negative or max than 'INT_MAX / HZ'.
Signed-off-by: NZhangXiaoxu <zhangxiaoxu5@huawei.com>
Acked-by: NSimon Horman <horms@verge.net.au>
Signed-off-by: NPablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      e0b03a6b
  15. 27 2月, 2019 7 次提交
  17. 26 1月, 2019 1 次提交
    • S
      netfilter: ipset: Allow matching on destination MAC address for mac and ipmac sets · ad7013cd
      由 Stefano Brivio 提交于 
      [ Upstream commit 8cc4ccf58379935f3ad456cc34e61c4e4c921d0e ]

There doesn't seem to be any reason to restrict MAC address
matching to source MAC addresses in set types bitmap:ipmac,
hash:ipmac and hash:mac. With this patch, and this setup:

  ip netns add A
  ip link add veth1 type veth peer name veth2 netns A
  ip addr add 192.0.2.1/24 dev veth1
  ip -net A addr add 192.0.2.2/24 dev veth2
  ip link set veth1 up
  ip -net A link set veth2 up

  ip netns exec A ipset create test hash:mac
  dst=$(ip netns exec A cat /sys/class/net/veth2/address)
  ip netns exec A ipset add test ${dst}
  ip netns exec A iptables -P INPUT DROP
  ip netns exec A iptables -I INPUT -m set --match-set test dst -j ACCEPT

ipset will match packets based on destination MAC address:

  # ping -c1 192.0.2.2 >/dev/null
  # echo $?
  0
Reported-by: NYi Chen <yiche@redhat.com>
Signed-off-by: NStefano Brivio <sbrivio@redhat.com>
Signed-off-by: NJozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Signed-off-by: NSasha Levin <sashal@kernel.org>
      ad7013cd
  19. 23 1月, 2019 4 次提交