linux-stable.git/net/ipv4/netfilter, branch v4.20.2

netfilter: nat: fix double register in masquerade modules

2018-11-26T23:36:46+00:00

There is a reference counter to ensure that masquerade modules register
notifiers only once. However, the existing reference counter approach is
not safe, test commands are:

   while :
   do
   	   modprobe ip6t_MASQUERADE &
	   modprobe nft_masq_ipv6 &
	   modprobe -rv ip6t_MASQUERADE &
	   modprobe -rv nft_masq_ipv6 &
   done

numbers below represent the reference counter.
--------------------------------------------------------
CPU0        CPU1        CPU2        CPU3        CPU4
[insmod]    [insmod]    [rmmod]     [rmmod]     [insmod]
--------------------------------------------------------
0->1
register    1->2
            returns     2->1
			returns     1->0
                                                0->1
                                                register <--
                                    unregister
--------------------------------------------------------

The unregistation of CPU3 should be processed before the
registration of CPU4.

In order to fix this, use a mutex instead of reference counter.

splat looks like:
[  323.869557] watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [modprobe:1381]
[  323.869574] Modules linked in: nf_tables(+) nf_nat_ipv6(-) nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 n]
[  323.869574] irq event stamp: 194074
[  323.898930] hardirqs last  enabled at (194073): [] trace_hardirqs_on_thunk+0x1a/0x1c
[  323.898930] hardirqs last disabled at (194074): [] trace_hardirqs_off_thunk+0x1a/0x1c
[  323.898930] softirqs last  enabled at (182132): [] __do_softirq+0x6ec/0xa3b
[  323.898930] softirqs last disabled at (182109): [] irq_exit+0x1a6/0x1e0
[  323.898930] CPU: 0 PID: 1381 Comm: modprobe Not tainted 4.20.0-rc2+ #27
[  323.898930] RIP: 0010:raw_notifier_chain_register+0xea/0x240
[  323.898930] Code: 3c 03 0f 8e f2 00 00 00 44 3b 6b 10 7f 4d 49 bc 00 00 00 00 00 fc ff df eb 22 48 8d 7b 10 488
[  323.898930] RSP: 0018:ffff888101597218 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
[  323.898930] RAX: 0000000000000000 RBX: ffffffffc04361c0 RCX: 0000000000000000
[  323.898930] RDX: 1ffffffff26132ae RSI: ffffffffc04aa3c0 RDI: ffffffffc04361d0
[  323.898930] RBP: ffffffffc04361c8 R08: 0000000000000000 R09: 0000000000000001
[  323.898930] R10: ffff8881015972b0 R11: fffffbfff26132c4 R12: dffffc0000000000
[  323.898930] R13: 0000000000000000 R14: 1ffff110202b2e44 R15: ffffffffc04aa3c0
[  323.898930] FS:  00007f813ed41540(0000) GS:ffff88811ae00000(0000) knlGS:0000000000000000
[  323.898930] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  323.898930] CR2: 0000559bf2c9f120 CR3: 000000010bc80000 CR4: 00000000001006f0
[  323.898930] Call Trace:
[  323.898930]  ? atomic_notifier_chain_register+0x2d0/0x2d0
[  323.898930]  ? down_read+0x150/0x150
[  323.898930]  ? sched_clock_cpu+0x126/0x170
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  register_netdevice_notifier+0xbb/0x790
[  323.898930]  ? __dev_close_many+0x2d0/0x2d0
[  323.898930]  ? __mutex_unlock_slowpath+0x17f/0x740
[  323.898930]  ? wait_for_completion+0x710/0x710
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  323.898930]  ? up_write+0x6c/0x210
[  323.898930]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  324.127073]  ? nf_tables_core_module_init+0xe4/0xe4 [nf_tables]
[  324.127073]  nft_chain_filter_init+0x1e/0xe8a [nf_tables]
[  324.127073]  nf_tables_module_init+0x37/0x92 [nf_tables]
[ ... ]

Fixes: 8dd33cc93ec9 ("netfilter: nf_nat: generalize IPv4 masquerading support for nf_tables")
Fixes: be6b635cd674 ("netfilter: nf_nat: generalize IPv6 masquerading support for nf_tables")
Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso

netfilter: add missing error handling code for register functions

2018-11-26T23:35:19+00:00

register_{netdevice/inetaddr/inet6addr}_notifier may return an error
value, this patch adds the code to handle these error paths.

Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso

netfilter: nf_nat_snmp_basic: add missing helper alias name

2018-10-16T08:01:50+00:00

In order to upload helper module automatically, helper alias name
is needed. so that MODULE_ALIAS_NFCT_HELPER() should be added.
And unlike other nat helper modules, the nf_nat_snmp_basic can be
used independently.
helper name is "snmp_trap" so that alias name will be
"nfct-helper-snmp_trap" by MODULE_ALIAS_NFCT_HELPER(snmp_trap)

test command:
   %iptables -t raw -I PREROUTING -p udp -j CT --helper snmp_trap
   %lsmod | grep nf_nat_snmp_basic

We can see nf_nat_snmp_basic module is uploaded automatically.

Signed-off-by: Taehee Yoo 
Signed-off-by: Pablo Neira Ayuso

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

2018-10-09T04:28:55+00:00

Pablo Neira Ayuso says:

====================
Netfilter updates for net-next

The following patchset contains Netfilter updates for your net-next tree:

1) Support for matching on ipsec policy already set in the route, from
   Florian Westphal.

2) Split set destruction into deactivate and destroy phase to make it
   fit better into the transaction infrastructure, also from Florian.
   This includes a patch to warn on imbalance when setting the new
   activate and deactivate interfaces.

3) Release transaction list from the workqueue to remove expensive
   synchronize_rcu() from configuration plane path. This speeds up
   configuration plane quite a bit. From Florian Westphal.

4) Add new xfrm/ipsec extension, this new extension allows you to match
   for ipsec tunnel keys such as source and destination address, spi and
   reqid. From Máté Eckl and Florian Westphal.

5) Add secmark support, this includes connsecmark too, patches
   from Christian Gottsche.

6) Allow to specify remaining bytes in xt_quota, from Chenbo Feng.
   One follow up patch to calm a clang warning for this one, from
   Nathan Chancellor.

7) Flush conntrack entries based on layer 3 family, from Kristian Evensen.

8) New revision for cgroups2 to shrink the path field.

9) Get rid of obsolete need_conntrack(), as a result from recent
   demodularization works.

10) Use WARN_ON instead of BUG_ON, from Florian Westphal.

11) Unused exported symbol in nf_nat_ipv4_fn(), from Florian.

12) Remove superfluous check for timeout netlink parser and dump
    functions in layer 4 conntrack helpers.

13) Unnecessary redundant rcu read side locks in NAT redirect,
    from Taehee Yoo.

14) Pass nf_hook_state structure to error handlers, patch from
    Florian Westphal.

15) Remove ->new() interface from layer 4 protocol trackers. Place
    them in the ->packet() interface. From Florian.

16) Place conntrack ->error() handling in the ->packet() interface.
    Patches from Florian Westphal.

17) Remove unused parameter in the pernet initialization path,
    also from Florian.

18) Remove additional parameter to specify layer 3 protocol when
    looking up for protocol tracker. From Florian.

19) Shrink array of layer 4 protocol trackers, from Florian.

20) Check for linear skb only once from the ALG NAT mangling
    codebase, from Taehee Yoo.

21) Use rhashtable_walk_enter() instead of deprecated
    rhashtable_walk_init(), also from Taehee.

22) No need to flush all conntracks when only one single address
    is gone, from Tan Hu.

23) Remove redundant check for NAT flags in flowtable code, from
    Taehee Yoo.

24) Use rhashtable_lookup() instead of rhashtable_lookup_fast()
    from netfilter codebase, since rcu read lock side is already
    assumed in this path.
====================

Signed-off-by: David S. Miller

netfilter: masquerade: don't flush all conntracks if only one address deleted on device

2018-09-28T12:28:26+00:00

We configured iptables as below, which only allowed incoming data on
established connections:

iptables -t mangle -A PREROUTING -m state --state ESTABLISHED -j ACCEPT
iptables -t mangle -P PREROUTING DROP

When deleting a secondary address, current masquerade implements would
flush all conntracks on this device. All the established connections on
primary address also be deleted, then subsequent incoming data on the
connections would be dropped wrongly because it was identified as NEW
connection.

So when an address was delete, it should only flush connections related
with the address.

Signed-off-by: Tan Hu 
Signed-off-by: Pablo Neira Ayuso

netfilter: nft_fib: Convert nft_fib4_eval to new dev helper

2018-09-21T03:01:53+00:00

Convert nft_fib4_eval to the new device checking helper and
remove the duplicate code.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

netfilter: rpfilter: Convert rpfilter_lookup_reverse to new dev helper

2018-09-21T03:01:52+00:00

Convert rpfilter_lookup_reverse to the new device checking helper
and remove the duplicate code.

Signed-off-by: David Ahern 
Signed-off-by: David S. Miller

netfilter: nf_nat_ipv4: remove obsolete EXPORT_SYMBOL

2018-09-17T14:11:13+00:00

There are no external callers anymore, previous change just
forgot to also remove the EXPORT_SYMBOL().

Fixes: 9971a514ed269 ("netfilter: nf_nat: add nat type hooks to nat core")
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso

netfilter: kconfig: nat related expression depend on nftables core

2018-08-31T17:07:10+00:00

NF_TABLES_IPV4 is now boolean so it is possible to set

NF_TABLES=m
NF_TABLES_IPV4=y
NFT_CHAIN_NAT_IPV4=y

which causes:
nft_chain_nat_ipv4.c:(.text+0x6d): undefined reference to `nft_do_chain'

Wrap NFT_CHAIN_NAT_IPV4 and related nat expressions with NF_TABLES to
restore the dependency.

Reported-by: Randy Dunlap 
Fixes: 02c7b25e5f54 ("netfilter: nf_tables: build-in filter chain type")
Signed-off-by: Florian Westphal 
Acked-by: Randy Dunlap 
Signed-off-by: Pablo Neira Ayuso

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

2018-07-21T05:28:28+00:00

Pablo Neira Ayuso says:

====================
Netfilter/IPVS updates for net-next

The following patchset contains Netfilter/IPVS updates for your net-next
tree:

1) No need to set ttl from reject action for the bridge family, from
   Taehee Yoo.

2) Use a fixed timeout for flow that are passed up from the flowtable
   to conntrack, from Florian Westphal.

3) More preparation patches for tproxy support for nf_tables, from Mate
   Eckl.

4) Remove unnecessary indirection in core IPv6 checksum function, from
   Florian Westphal.

5) Use nf_ct_get_tuplepr() from openvswitch, instead of opencoding it.
   From Florian Westphal.

6) socket match now selects socket infrastructure, instead of depending
   on it. From Mate Eckl.

7) Patch series to simplify conntrack tuple building/parsing from packet
   path and ctnetlink, from Florian Westphal.

8) Fetch timeout policy from protocol helpers, instead of doing it from
   core, from Florian Westphal.

9) Merge IPv4 and IPv6 protocol trackers into conntrack core, from
   Florian Westphal.

10) Depend on CONFIG_NF_TABLES_IPV6 and CONFIG_IP6_NF_IPTABLES
    respectively, instead of IPV6. Patch from Mate Eckl.

11) Add specific function for garbage collection in conncount,
    from Yi-Hung Wei.

12) Catch number of elements in the connlimit list, from Yi-Hung Wei.

13) Move locking to nf_conncount, from Yi-Hung Wei.

14) Series of patches to add lockless tree traversal in nf_conncount,
    from Yi-Hung Wei.

15) Resolve clash in matching conntracks when race happens, from
    Martynas Pumputis.

16) If connection entry times out, remove template entry from the
    ip_vs_conn_tab table to improve behaviour under flood, from
    Julian Anastasov.

17) Remove useless parameter from nf_ct_helper_ext_add(), from Gao feng.

18) Call abort from 2-phase commit protocol before requesting modules,
    make sure this is done under the mutex, from Florian Westphal.

19) Grab module reference when starting transaction, also from Florian.

20) Dynamically allocate expression info array for pre-parsing, from
    Florian.

21) Add per netns mutex for nf_tables, from Florian Westphal.

22) A couple of patches to simplify and refactor nf_osf code to prepare
    for nft_osf support.

23) Break evaluation on missing socket, from Mate Eckl.

24) Allow to match socket mark from nft_socket, from Mate Eckl.

25) Remove dependency on nf_defrag_ipv6, now that IPv6 tracker is
    built-in into nf_conntrack. From Florian Westphal.
====================

Signed-off-by: David S. Miller