Quoting Andrey Vagin:
When a conntrack is created by kernel, it is initialized (sets
IPS_{DST,SRC}_NAT_DONE_BIT bits in nf_nat_setup_info) and only then it
is added in hashes (__nf_conntrack_hash_insert), so one conntract
can't be initialized from a few threads concurrently.
ctnetlink can add an uninitialized conntrack (w/o
IPS_{DST,SRC}_NAT_DONE_BIT) in hashes, then a few threads can look up
this conntrack and start initialize it concurrently. It's dangerous,
because BUG can be triggered from nf_nat_setup_info.
Fix this race by always setting up nat, even if no CTA_NAT_ attribute
was requested before inserting the ct into the hash table. In absence
of CTA_NAT_ attribute, a null binding is created.
This alters current behaviour: Before this patch, the first packet
matching the newly injected conntrack would be run through the nat
table since nf_nat_initialized() returns false. IOW, this forces
ctnetlink users to specify the desired nat transformation on ct
creation time.
Thanks for Florian Westphal, this patch is based on his original
patch to address this problem, including this patch description.
Reported-By: Andrey Vagin <avagin@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Florian Westphal <fw@strlen.de>
Add a check if payload's length is a power of 2 when selecting ops.
The fast ops were meant for well aligned loads, also this fixes a
small bug when using a length of 3 with some offsets which causes
only 1 byte to be loaded because the fast ops are chosen.
Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There are two checks for CONFIG_NET_CLS_ROUTE, but the corresponding
Kconfig symbol was dropped in v2.6.39. Since the code guards access to
dst_entry.tclassid it seems CONFIG_IP_ROUTE_CLASSID should be used
instead.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Include appropriate header file net/netfilter/nf_tables_core.h in
net/netfilter/nft_lookup.c because it has prototype declaration of
functions defined in net/netfilter/nft_lookup.c.
This eliminates the following warning in net/netfilter/nft_lookup.c:
net/netfilter/nft_lookup.c:133:12: warning: no previous prototype for ‘nft_lookup_module_init’ [-Wmissing-prototypes]
net/netfilter/nft_lookup.c:138:6: warning: no previous prototype for ‘nft_lookup_module_exit’ [-Wmissing-prototypes]
Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
It makes no sense to inline a rarely used function meant for debugging
only that is called a total of five times in the main evaluation loop.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fix access to uninitialized data for end interval elements. The
element data part is uninitialized in interval end elements.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch fixes several things which related to the handling of
end interval elements:
* Chain use underflow with intervals and map: If you add a rule
using intervals+map that introduces a loop, the error path of the
rbtree set decrements the chain refcount for each side of the
interval, leading to a chain use counter underflow.
* Don't copy the data part of the end interval element since, this
area is uninitialized and this confuses the loop detection code.
* Don't allocate room for the data part of end interval elements
since this is unused.
So, after this patch the idea is that end interval elements don't
have a data part.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>
This combination is not allowed since end interval elements cannot
contain data.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Acked-by: Patrick McHardy <kaber@trash.net>
We may lost race if we flush the rule-set (which happens asynchronously
via call_rcu) and we try to remove the table (that userspace assumes
to be empty).
Fix this by recovering synchronous rule and chain deletion. This was
introduced time ago before we had no batch support, and synchronous
rule deletion performance was not good. Now that we have the batch
support, we can just postpone the purge of old rule in a second step
in the commit phase. All object deletions are synchronous after this
patch.
As a side effect, we save memory as we don't need rcu_head per rule
anymore.
Cc: Patrick McHardy <kaber@trash.net>
Reported-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The log and queue expressions both store the family during ->init() and
use it to deliver packets. This is wrong when used in NFPROTO_INET since
they should both deliver to the actual AF of the packet, not the dummy
NFPROTO_INET.
Use the family from the hook ops to fix this.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add a reject module for NFPROTO_INET. It does nothing but dispatch
to the AF-specific modules based on the hook family.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently the nft_reject module depends on symbols from ipv6. This is
wrong since no generic module should force IPv6 support to be loaded.
Split up the module into AF-specific and a generic part.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For the reject module, we need to add AF-specific implementations to
get rid of incorrect module dependencies. Try to load an AF-specific
module first and fall back to generic modules.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The key was missing in the list of valid keys, add it.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit c9c8e48597 (netfilter: nf_tables: dump sets in all existing families)
changed nft_ctx_init_from_setattr() to only look up the address family if it
is not NFPROTO_UNSPEC. However if it is NFPROTO_UNSPEC and a table attribute
is given, nftables_afinfo_lookup() will dereference the NULL afi pointer.
Fix by checking for non-NULL afi and also move a check added by that commit
to the proper position.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The map that is used to allocate anonymous sets is indeed
BITS_PER_BYTE * PAGE_SIZE long.
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With this patch, the conntrack refcount is initially set to zero and
it is bumped once it is added to any of the list, so we fulfill
Eric's golden rule which is that all released objects always have a
refcount that equals zero.
Andrey Vagin reports that nf_conntrack_free can't be called for a
conntrack with non-zero ref-counter, because it can race with
nf_conntrack_find_get().
A conntrack slab is created with SLAB_DESTROY_BY_RCU. Non-zero
ref-counter says that this conntrack is used. So when we release
a conntrack with non-zero counter, we break this assumption.
CPU1 CPU2
____nf_conntrack_find()
nf_ct_put()
destroy_conntrack()
...
init_conntrack
__nf_conntrack_alloc (set use = 1)
atomic_inc_not_zero(&ct->use) (use = 2)
if (!l4proto->new(ct, skb, dataoff, timeouts))
nf_conntrack_free(ct); (use = 2 !!!)
...
__nf_conntrack_alloc (set use = 1)
if (!nf_ct_key_equal(h, tuple, zone))
nf_ct_put(ct); (use = 0)
destroy_conntrack()
/* continue to work with CT */
After applying the path "[PATCH] netfilter: nf_conntrack: fix RCU
race in nf_conntrack_find_get" another bug was triggered in
destroy_conntrack():
<4>[67096.759334] ------------[ cut here ]------------
<2>[67096.759353] kernel BUG at net/netfilter/nf_conntrack_core.c:211!
...
<4>[67096.759837] Pid: 498649, comm: atdd veid: 666 Tainted: G C --------------- 2.6.32-042stab084.18 #1 042stab084_18 /DQ45CB
<4>[67096.759932] RIP: 0010:[<ffffffffa03d99ac>] [<ffffffffa03d99ac>] destroy_conntrack+0x15c/0x190 [nf_conntrack]
<4>[67096.760255] Call Trace:
<4>[67096.760255] [<ffffffff814844a7>] nf_conntrack_destroy+0x17/0x30
<4>[67096.760255] [<ffffffffa03d9bb5>] nf_conntrack_find_get+0x85/0x130 [nf_conntrack]
<4>[67096.760255] [<ffffffffa03d9fb2>] nf_conntrack_in+0x352/0xb60 [nf_conntrack]
<4>[67096.760255] [<ffffffffa048c771>] ipv4_conntrack_local+0x51/0x60 [nf_conntrack_ipv4]
<4>[67096.760255] [<ffffffff81484419>] nf_iterate+0x69/0xb0
<4>[67096.760255] [<ffffffff814b5b00>] ? dst_output+0x0/0x20
<4>[67096.760255] [<ffffffff814845d4>] nf_hook_slow+0x74/0x110
<4>[67096.760255] [<ffffffff814b5b00>] ? dst_output+0x0/0x20
<4>[67096.760255] [<ffffffff814b66d5>] raw_sendmsg+0x775/0x910
<4>[67096.760255] [<ffffffff8104c5a8>] ? flush_tlb_others_ipi+0x128/0x130
<4>[67096.760255] [<ffffffff8100bc4e>] ? apic_timer_interrupt+0xe/0x20
<4>[67096.760255] [<ffffffff8100bc4e>] ? apic_timer_interrupt+0xe/0x20
<4>[67096.760255] [<ffffffff814c136a>] inet_sendmsg+0x4a/0xb0
<4>[67096.760255] [<ffffffff81444e93>] ? sock_sendmsg+0x13/0x140
<4>[67096.760255] [<ffffffff81444f97>] sock_sendmsg+0x117/0x140
<4>[67096.760255] [<ffffffff8102e299>] ? native_smp_send_reschedule+0x49/0x60
<4>[67096.760255] [<ffffffff81519beb>] ? _spin_unlock_bh+0x1b/0x20
<4>[67096.760255] [<ffffffff8109d930>] ? autoremove_wake_function+0x0/0x40
<4>[67096.760255] [<ffffffff814960f0>] ? do_ip_setsockopt+0x90/0xd80
<4>[67096.760255] [<ffffffff8100bc4e>] ? apic_timer_interrupt+0xe/0x20
<4>[67096.760255] [<ffffffff8100bc4e>] ? apic_timer_interrupt+0xe/0x20
<4>[67096.760255] [<ffffffff814457c9>] sys_sendto+0x139/0x190
<4>[67096.760255] [<ffffffff810efa77>] ? audit_syscall_entry+0x1d7/0x200
<4>[67096.760255] [<ffffffff810ef7c5>] ? __audit_syscall_exit+0x265/0x290
<4>[67096.760255] [<ffffffff81474daf>] compat_sys_socketcall+0x13f/0x210
<4>[67096.760255] [<ffffffff8104dea3>] ia32_sysret+0x0/0x5
I have reused the original title for the RFC patch that Andrey posted and
most of the original patch description.
Cc: Eric Dumazet <edumazet@google.com>
Cc: Andrew Vagin <avagin@parallels.com>
Cc: Florian Westphal <fw@strlen.de>
Reported-by: Andrew Vagin <avagin@parallels.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Andrew Vagin <avagin@parallels.com>
Lets look at destroy_conntrack:
hlist_nulls_del_rcu(&ct->tuplehash[IP_CT_DIR_ORIGINAL].hnnode);
...
nf_conntrack_free(ct)
kmem_cache_free(net->ct.nf_conntrack_cachep, ct);
net->ct.nf_conntrack_cachep is created with SLAB_DESTROY_BY_RCU.
The hash is protected by rcu, so readers look up conntracks without
locks.
A conntrack is removed from the hash, but in this moment a few readers
still can use the conntrack. Then this conntrack is released and another
thread creates conntrack with the same address and the equal tuple.
After this a reader starts to validate the conntrack:
* It's not dying, because a new conntrack was created
* nf_ct_tuple_equal() returns true.
But this conntrack is not initialized yet, so it can not be used by two
threads concurrently. In this case BUG_ON may be triggered from
nf_nat_setup_info().
Florian Westphal suggested to check the confirm bit too. I think it's
right.
task 1 task 2 task 3
nf_conntrack_find_get
____nf_conntrack_find
destroy_conntrack
hlist_nulls_del_rcu
nf_conntrack_free
kmem_cache_free
__nf_conntrack_alloc
kmem_cache_alloc
memset(&ct->tuplehash[IP_CT_DIR_MAX],
if (nf_ct_is_dying(ct))
if (!nf_ct_tuple_equal()
I'm not sure, that I have ever seen this race condition in a real life.
Currently we are investigating a bug, which is reproduced on a few nodes.
In our case one conntrack is initialized from a few tasks concurrently,
we don't have any other explanation for this.
<2>[46267.083061] kernel BUG at net/ipv4/netfilter/nf_nat_core.c:322!
...
<4>[46267.083951] RIP: 0010:[<ffffffffa01e00a4>] [<ffffffffa01e00a4>] nf_nat_setup_info+0x564/0x590 [nf_nat]
...
<4>[46267.085549] Call Trace:
<4>[46267.085622] [<ffffffffa023421b>] alloc_null_binding+0x5b/0xa0 [iptable_nat]
<4>[46267.085697] [<ffffffffa02342bc>] nf_nat_rule_find+0x5c/0x80 [iptable_nat]
<4>[46267.085770] [<ffffffffa0234521>] nf_nat_fn+0x111/0x260 [iptable_nat]
<4>[46267.085843] [<ffffffffa0234798>] nf_nat_out+0x48/0xd0 [iptable_nat]
<4>[46267.085919] [<ffffffff814841b9>] nf_iterate+0x69/0xb0
<4>[46267.085991] [<ffffffff81494e70>] ? ip_finish_output+0x0/0x2f0
<4>[46267.086063] [<ffffffff81484374>] nf_hook_slow+0x74/0x110
<4>[46267.086133] [<ffffffff81494e70>] ? ip_finish_output+0x0/0x2f0
<4>[46267.086207] [<ffffffff814b5890>] ? dst_output+0x0/0x20
<4>[46267.086277] [<ffffffff81495204>] ip_output+0xa4/0xc0
<4>[46267.086346] [<ffffffff814b65a4>] raw_sendmsg+0x8b4/0x910
<4>[46267.086419] [<ffffffff814c10fa>] inet_sendmsg+0x4a/0xb0
<4>[46267.086491] [<ffffffff814459aa>] ? sock_update_classid+0x3a/0x50
<4>[46267.086562] [<ffffffff81444d67>] sock_sendmsg+0x117/0x140
<4>[46267.086638] [<ffffffff8151997b>] ? _spin_unlock_bh+0x1b/0x20
<4>[46267.086712] [<ffffffff8109d370>] ? autoremove_wake_function+0x0/0x40
<4>[46267.086785] [<ffffffff81495e80>] ? do_ip_setsockopt+0x90/0xd80
<4>[46267.086858] [<ffffffff8100be0e>] ? call_function_interrupt+0xe/0x20
<4>[46267.086936] [<ffffffff8118cb10>] ? ub_slab_ptr+0x20/0x90
<4>[46267.087006] [<ffffffff8118cb10>] ? ub_slab_ptr+0x20/0x90
<4>[46267.087081] [<ffffffff8118f2e8>] ? kmem_cache_alloc+0xd8/0x1e0
<4>[46267.087151] [<ffffffff81445599>] sys_sendto+0x139/0x190
<4>[46267.087229] [<ffffffff81448c0d>] ? sock_setsockopt+0x16d/0x6f0
<4>[46267.087303] [<ffffffff810efa47>] ? audit_syscall_entry+0x1d7/0x200
<4>[46267.087378] [<ffffffff810ef795>] ? __audit_syscall_exit+0x265/0x290
<4>[46267.087454] [<ffffffff81474885>] ? compat_sys_setsockopt+0x75/0x210
<4>[46267.087531] [<ffffffff81474b5f>] compat_sys_socketcall+0x13f/0x210
<4>[46267.087607] [<ffffffff8104dea3>] ia32_sysret+0x0/0x5
<4>[46267.087676] Code: 91 20 e2 01 75 29 48 89 de 4c 89 f7 e8 56 fa ff ff 85 c0 0f 84 68 fc ff ff 0f b6 4d c6 41 8b 45 00 e9 4d fb ff ff e8 7c 19 e9 e0 <0f> 0b eb fe f6 05 17 91 20 e2 80 74 ce 80 3d 5f 2e 00 00 00 74
<1>[46267.088023] RIP [<ffffffffa01e00a4>] nf_nat_setup_info+0x564/0x590
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Florian Westphal <fw@strlen.de>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Cc: Patrick McHardy <kaber@trash.net>
Cc: Jozsef Kadlecsik <kadlec@blackhole.kfki.hu>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Signed-off-by: Andrey Vagin <avagin@openvz.org>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The following commands trigger an oops:
# nft -i
nft> add table filter
nft> add chain filter input { type filter hook input priority 0; }
nft> add chain filter test
nft> add rule filter input jump test
nft> delete chain filter test
We need to check the chain use counter before allowing destruction since
we might have references from sets or jump rules.
Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=69341
Reported-by: Matthew Ife <deleriux1@gmail.com>
Tested-by: Matthew Ife <deleriux1@gmail.com>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
We want to make sure that the information that we get from the kernel can
be reinjected without troubles. The kernel shouldn't return an attribute
that is not required, or even prohibited.
Dumping unconditionally NFTA_CT_DIRECTION could lead an application in
userspace to interpret that the attribute was originally set, while it
was not.
Signed-off-by: Arturo Borrero Gonzalez <arturo.borrero.glez@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If a fwmark is passed to ip_vs_conn_new(), it is passed in
vaddr, not daddr. Therefore we should set AF to AF_UNSPEC in
vaddr assignment (like we do in ip_vs_ct_in_get()), otherwise we
may copy only first 4 bytes of an IPv6 address into cp->daddr.
Signed-off-by: Bogdano Arendartchuk <barendartchuk@suse.com>
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Pull networking updates from David Miller:
1) BPF debugger and asm tool by Daniel Borkmann.
2) Speed up create/bind in AF_PACKET, also from Daniel Borkmann.
3) Correct reciprocal_divide and update users, from Hannes Frederic
Sowa and Daniel Borkmann.
4) Currently we only have a "set" operation for the hw timestamp socket
ioctl, add a "get" operation to match. From Ben Hutchings.
5) Add better trace events for debugging driver datapath problems, also
from Ben Hutchings.
6) Implement auto corking in TCP, from Eric Dumazet. Basically, if we
have a small send and a previous packet is already in the qdisc or
device queue, defer until TX completion or we get more data.
7) Allow userspace to manage ipv6 temporary addresses, from Jiri Pirko.
8) Add a qdisc bypass option for AF_PACKET sockets, from Daniel
Borkmann.
9) Share IP header compression code between Bluetooth and IEEE802154
layers, from Jukka Rissanen.
10) Fix ipv6 router reachability probing, from Jiri Benc.
11) Allow packets to be captured on macvtap devices, from Vlad Yasevich.
12) Support tunneling in GRO layer, from Jerry Chu.
13) Allow bonding to be configured fully using netlink, from Scott
Feldman.
14) Allow AF_PACKET users to obtain the VLAN TPID, just like they can
already get the TCI. From Atzm Watanabe.
15) New "Heavy Hitter" qdisc, from Terry Lam.
16) Significantly improve the IPSEC support in pktgen, from Fan Du.
17) Allow ipv4 tunnels to cache routes, just like sockets. From Tom
Herbert.
18) Add Proportional Integral Enhanced packet scheduler, from Vijay
Subramanian.
19) Allow openvswitch to mmap'd netlink, from Thomas Graf.
20) Key TCP metrics blobs also by source address, not just destination
address. From Christoph Paasch.
21) Support 10G in generic phylib. From Andy Fleming.
22) Try to short-circuit GRO flow compares using device provided RX
hash, if provided. From Tom Herbert.
The wireless and netfilter folks have been busy little bees too.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next: (2064 commits)
net/cxgb4: Fix referencing freed adapter
ipv6: reallocate addrconf router for ipv6 address when lo device up
fib_frontend: fix possible NULL pointer dereference
rtnetlink: remove IFLA_BOND_SLAVE definition
rtnetlink: remove check for fill_slave_info in rtnl_have_link_slave_info
qlcnic: update version to 5.3.55
qlcnic: Enhance logic to calculate msix vectors.
qlcnic: Refactor interrupt coalescing code for all adapters.
qlcnic: Update poll controller code path
qlcnic: Interrupt code cleanup
qlcnic: Enhance Tx timeout debugging.
qlcnic: Use bool for rx_mac_learn.
bonding: fix u64 division
rtnetlink: add missing IFLA_BOND_AD_INFO_UNSPEC
sfc: Use the correct maximum TX DMA ring size for SFC9100
Add Shradha Shah as the sfc driver maintainer.
net/vxlan: Share RX skb de-marking and checksum checks with ovs
tulip: cleanup by using ARRAY_SIZE()
ip_tunnel: clear IPCB in ip_tunnel_xmit() in case dst_link_failure() is called
net/cxgb4: Don't retrieve stats during recovery
...
Pull trivial tree updates from Jiri Kosina:
"Usual rocket science stuff from trivial.git"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (39 commits)
neighbour.h: fix comment
sched: Fix warning on make htmldocs caused by wait.h
slab: struct kmem_cache is protected by slab_mutex
doc: Fix typo in USB Gadget Documentation
of/Kconfig: Spelling s/one/once/
mkregtable: Fix sscanf handling
lp5523, lp8501: comment improvements
thermal: rcar: comment spelling
treewide: fix comments and printk msgs
IXP4xx: remove '1 &&' from a condition check in ixp4xx_restart()
Documentation: update /proc/uptime field description
Documentation: Fix size parameter for snprintf
arm: fix comment header and macro name
asm-generic: uaccess: Spelling s/a ny/any/
mtd: onenand: fix comment header
doc: driver-model/platform.txt: fix a typo
drivers: fix typo in DEVTMPFS_MOUNT Kconfig help text
doc: Fix typo (acces_process_vm -> access_process_vm)
treewide: Fix typos in printk
drivers/gpu/drm/qxl/Kconfig: reformat the help text
...
