linux-stable.git/net/netfilter, branch v5.4.86

netfilter: nft_ct: Remove confirmation check for NFT_CT_ID

2020-12-30T10:50:55+00:00

[ Upstream commit 2d94b20b95b009eec1a267dcf026b01af627c0cd ]

Since commit 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id
hash calculation") the ct id will not change from initialization to
confirmation.  Removing the confirmation check allows for things like
adding an element to a 'typeof ct id' set in prerouting upon reception
of the first packet of a new connection, and then being able to
reference that set consistently both before and after the connection
is confirmed.

Fixes: 656c8e9cc1ba ("netfilter: conntrack: Use consistent ct id hash calculation")
Signed-off-by: Brett Mastbergen 
Acked-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_dynset: fix timeouts later than 23 days

2020-12-30T10:50:54+00:00

[ Upstream commit 917d80d376ffbaa9725fde9e3c0282f63643f278 ]

Use nf_msecs_to_jiffies64 and nf_jiffies64_to_msecs as provided by
8e1102d5a159 ("netfilter: nf_tables: support timeouts larger than 23
days"), otherwise ruleset listing breaks.

Fixes: a8b1e36d0d1d ("netfilter: nft_dynset: fix element timeout for HZ != 1000")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nft_compat: make sure xtables destructors have run

2020-12-30T10:50:54+00:00

[ Upstream commit ffe8923f109b7ea92c0842c89e61300eefa11c94 ]

Pablo Neira found that after recent update of xt_IDLETIMER the
iptables-nft tests sometimes show an error.

He tracked this down to the delayed cleanup used by nf_tables core:
del rule (transaction A)
add rule (transaction B)

Its possible that by time transaction B (both in same netns) runs,
the xt target destructor has not been invoked yet.

For native nft expressions this is no problem because all expressions
that have such side effects make sure these are handled from the commit
phase, rather than async cleanup.

For nft_compat however this isn't true.

Instead of forcing synchronous behaviour for nft_compat, keep track
of the number of outstanding destructor calls.

When we attempt to create a new expression, flush the cleanup worker
to make sure destructors have completed.

With lots of help from Pablo Neira.

Reported-by: Pablo Neira Ayso 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: x_tables: Switch synchronization to RCU

2020-12-30T10:50:54+00:00

[ Upstream commit cc00bcaa589914096edef7fb87ca5cee4a166b5c ]

When running concurrent iptables rules replacement with data, the per CPU
sequence count is checked after the assignment of the new information.
The sequence count is used to synchronize with the packet path without the
use of any explicit locking. If there are any packets in the packet path using
the table information, the sequence count is incremented to an odd value and
is incremented to an even after the packet process completion.

The new table value assignment is followed by a write memory barrier so every
CPU should see the latest value. If the packet path has started with the old
table information, the sequence counter will be odd and the iptables
replacement will wait till the sequence count is even prior to freeing the
old table info.

However, this assumes that the new table information assignment and the memory
barrier is actually executed prior to the counter check in the replacement
thread. If CPU decides to execute the assignment later as there is no user of
the table information prior to the sequence check, the packet path in another
CPU may use the old table information. The replacement thread would then free
the table information under it leading to a use after free in the packet
processing context-

Unable to handle kernel NULL pointer dereference at virtual
address 000000000000008e
pc : ip6t_do_table+0x5d0/0x89c
lr : ip6t_do_table+0x5b8/0x89c
ip6t_do_table+0x5d0/0x89c
ip6table_filter_hook+0x24/0x30
nf_hook_slow+0x84/0x120
ip6_input+0x74/0xe0
ip6_rcv_finish+0x7c/0x128
ipv6_rcv+0xac/0xe4
__netif_receive_skb+0x84/0x17c
process_backlog+0x15c/0x1b8
napi_poll+0x88/0x284
net_rx_action+0xbc/0x23c
__do_softirq+0x20c/0x48c

This could be fixed by forcing instruction order after the new table
information assignment or by switching to RCU for the synchronization.

Fixes: 80055dab5de0 ("netfilter: x_tables: make xt_replace_table wait until old rules are not used anymore")
Reported-by: Sean Tranchetti 
Reported-by: kernel test robot 
Suggested-by: Florian Westphal 
Signed-off-by: Subash Abhinov Kasiviswanathan 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nftables_offload: set address type in control dissector

2020-12-11T12:23:33+00:00

commit 3c78e9e0d33a27ab8050e4492c03c6a1f8d0ed6b upstream.

This patch adds nft_flow_rule_set_addr_type() to set the address type
from the nft_payload expression accordingly.

If the address type is not set in the control dissector then a rule that
matches either on source or destination IP address does not work.

After this patch, nft hardware offload generates the flow dissector
configuration as tc-flower does to match on an IP address.

This patch has been also tested functionally to make sure packets are
filtered out by the NIC.

This is also getting the code aligned with the existing netfilter flow
offload infrastructure which is also setting the control dissector.

Fixes: c9626a2cbdb2 ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: nf_tables: avoid false-postive lockdep splat

2020-12-11T12:23:33+00:00

commit c0700dfa2cae44c033ed97dade8a2679c7d22a9d upstream.

There are reports wrt lockdep splat in nftables, e.g.:
------------[ cut here ]------------
WARNING: CPU: 2 PID: 31416 at net/netfilter/nf_tables_api.c:622
lockdep_nfnl_nft_mutex_not_held+0x28/0x38 [nf_tables]
...

These are caused by an earlier, unrelated bug such as a n ABBA deadlock
in a different subsystem.
In such an event, lockdep is disabled and lockdep_is_held returns true
unconditionally.  This then causes the WARN() in nf_tables.

Make the WARN conditional on lockdep still active to avoid this.

Fixes: f102d66b335a417 ("netfilter: nf_tables: use dedicated mutex to guard transactions")
Reported-by: Naresh Kamboju 
Link: https://lore.kernel.org/linux-kselftest/CA+G9fYvFUpODs+NkSYcnwKnXm62tmP=ksLeBPmB+KFrB2rvCtQ@mail.gmail.com/
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: ipset: prevent uninit-value in hash_ip6_add

2020-12-11T12:23:32+00:00

commit 68ad89de918e1c5a79c9c56127e5e31741fd517e upstream.

syzbot found that we are not validating user input properly
before copying 16 bytes [1].

Using NLA_BINARY in ipaddr_policy[] for IPv6 address is not correct,
since it ensures at most 16 bytes were provided.

We should instead make sure user provided exactly 16 bytes.

In old kernels (before v4.20), fix would be to remove the NLA_BINARY,
since NLA_POLICY_EXACT_LEN() was not yet available.

[1]
BUG: KMSAN: uninit-value in hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
CPU: 1 PID: 11611 Comm: syz-executor.0 Not tainted 5.10.0-rc4-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:118
 __msan_warning+0x5f/0xa0 mm/kmsan/kmsan_instr.c:197
 hash_ip6_add+0x1cba/0x3a50 net/netfilter/ipset/ip_set_hash_gen.h:892
 hash_ip6_uadt+0x976/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:267
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45deb9
Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe2e503fc78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000029ec0 RCX: 000000000045deb9
RDX: 0000000000000000 RSI: 0000000020000140 RDI: 0000000000000003
RBP: 000000000118bf60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c
R13: 000000000169fb7f R14: 00007fe2e50409c0 R15: 000000000118bf2c

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 __msan_chain_origin+0x57/0xa0 mm/kmsan/kmsan_instr.c:147
 ip6_netmask include/linux/netfilter/ipset/pfxlen.h:49 [inline]
 hash_ip6_netmask net/netfilter/ipset/ip_set_hash_ip.c:185 [inline]
 hash_ip6_uadt+0xb1c/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:263
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was stored to memory at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_chain_origin+0xad/0x130 mm/kmsan/kmsan.c:289
 kmsan_memcpy_memmove_metadata+0x25e/0x2d0 mm/kmsan/kmsan.c:226
 kmsan_memcpy_metadata+0xb/0x10 mm/kmsan/kmsan.c:246
 __msan_memcpy+0x46/0x60 mm/kmsan/kmsan_instr.c:110
 ip_set_get_ipaddr6+0x2cb/0x370 net/netfilter/ipset/ip_set_core.c:310
 hash_ip6_uadt+0x439/0xbd0 net/netfilter/ipset/ip_set_hash_ip.c:255
 call_ad+0x329/0xd00 net/netfilter/ipset/ip_set_core.c:1720
 ip_set_ad+0x111f/0x1440 net/netfilter/ipset/ip_set_core.c:1808
 ip_set_uadd+0xf6/0x110 net/netfilter/ipset/ip_set_core.c:1833
 nfnetlink_rcv_msg+0xc7d/0xdf0 net/netfilter/nfnetlink.c:252
 netlink_rcv_skb+0x70a/0x820 net/netlink/af_netlink.c:2494
 nfnetlink_rcv+0x4f0/0x4380 net/netfilter/nfnetlink.c:600
 netlink_unicast_kernel net/netlink/af_netlink.c:1304 [inline]
 netlink_unicast+0x11da/0x14b0 net/netlink/af_netlink.c:1330
 netlink_sendmsg+0x173c/0x1840 net/netlink/af_netlink.c:1919
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Uninit was created at:
 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:121 [inline]
 kmsan_internal_poison_shadow+0x5c/0xf0 mm/kmsan/kmsan.c:104
 kmsan_slab_alloc+0x8d/0xe0 mm/kmsan/kmsan_hooks.c:76
 slab_alloc_node mm/slub.c:2906 [inline]
 __kmalloc_node_track_caller+0xc61/0x15f0 mm/slub.c:4512
 __kmalloc_reserve net/core/skbuff.c:142 [inline]
 __alloc_skb+0x309/0xae0 net/core/skbuff.c:210
 alloc_skb include/linux/skbuff.h:1094 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1176 [inline]
 netlink_sendmsg+0xdb8/0x1840 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:651 [inline]
 sock_sendmsg net/socket.c:671 [inline]
 ____sys_sendmsg+0xc7a/0x1240 net/socket.c:2353
 ___sys_sendmsg net/socket.c:2407 [inline]
 __sys_sendmsg+0x6d5/0x830 net/socket.c:2440
 __do_sys_sendmsg net/socket.c:2449 [inline]
 __se_sys_sendmsg+0x97/0xb0 net/socket.c:2447
 __x64_sys_sendmsg+0x4a/0x70 net/socket.c:2447
 do_syscall_64+0x9f/0x140 arch/x86/entry/common.c:48
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Fixes: a7b4f989a629 ("netfilter: ipset: IP set core support")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Acked-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Greg Kroah-Hartman

netfilter: ipset: Update byte and packet counters regardless of whether they match

2020-11-18T18:20:17+00:00

[ Upstream commit 7d10e62c2ff8e084c136c94d32d9a94de4d31248 ]

In ip_set_match_extensions(), for sets with counters, we take care of
updating counters themselves by calling ip_set_update_counter(), and of
checking if the given comparison and values match, by calling
ip_set_match_counter() if needed.

However, if a given comparison on counters doesn't match the configured
values, that doesn't mean the set entry itself isn't matching.

This fix restores the behaviour we had before commit 4750005a85f7
("netfilter: ipset: Fix "don't update counters" mode when counters used
at the matching"), without reintroducing the issue fixed there: back
then, mtype_data_match() first updated counters in any case, and then
took care of matching on counters.

Now, if the IPSET_FLAG_SKIP_COUNTER_UPDATE flag is set,
ip_set_update_counter() will anyway skip counter updates if desired.

The issue observed is illustrated by this reproducer:

  ipset create c hash:ip counters
  ipset add c 192.0.2.1
  iptables -I INPUT -m set --match-set c src --bytes-gt 800 -j DROP

if we now send packets from 192.0.2.1, bytes and packets counters
for the entry as shown by 'ipset list' are always zero, and, no
matter how many bytes we send, the rule will never match, because
counters themselves are not updated.

Reported-by: Mithil Mhatre 
Fixes: 4750005a85f7 ("netfilter: ipset: Fix "don't update counters" mode when counters used at the matching")
Signed-off-by: Stefano Brivio 
Signed-off-by: Jozsef Kadlecsik 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: nf_tables: missing validation from the abort path

2020-11-18T18:20:17+00:00

[ Upstream commit c0391b6ab810381df632677a1dcbbbbd63d05b6d ]

If userspace does not include the trailing end of batch message, then
nfnetlink aborts the transaction. This allows to check that ruleset
updates trigger no errors.

After this patch, invoking this command from the prerouting chain:

 # nft -c add rule x y fib saddr . oif type local

fails since oif is not supported there.

This patch fixes the lack of rule validation from the abort/check path
to catch configuration errors such as the one above.

Fixes: a654de8fdc18 ("netfilter: nf_tables: fix chain dependency validation")
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin

netfilter: use actual socket sk rather than skb sk when routing harder

2020-11-18T18:20:17+00:00

[ Upstream commit 46d6c5ae953cc0be38efd0e469284df7c4328cf8 ]

If netfilter changes the packet mark when mangling, the packet is
rerouted using the route_me_harder set of functions. Prior to this
commit, there's one big difference between route_me_harder and the
ordinary initial routing functions, described in the comment above
__ip_queue_xmit():

   /* Note: skb->sk can be different from sk, in case of tunnels */
   int __ip_queue_xmit(struct sock *sk, struct sk_buff *skb, struct flowi *fl,

That function goes on to correctly make use of sk->sk_bound_dev_if,
rather than skb->sk->sk_bound_dev_if. And indeed the comment is true: a
tunnel will receive a packet in ndo_start_xmit with an initial skb->sk.
It will make some transformations to that packet, and then it will send
the encapsulated packet out of a *new* socket. That new socket will
basically always have a different sk_bound_dev_if (otherwise there'd be
a routing loop). So for the purposes of routing the encapsulated packet,
the routing information as it pertains to the socket should come from
that socket's sk, rather than the packet's original skb->sk. For that
reason __ip_queue_xmit() and related functions all do the right thing.

One might argue that all tunnels should just call skb_orphan(skb) before
transmitting the encapsulated packet into the new socket. But tunnels do
*not* do this -- and this is wisely avoided in skb_scrub_packet() too --
because features like TSQ rely on skb->destructor() being called when
that buffer space is truely available again. Calling skb_orphan(skb) too
early would result in buffers filling up unnecessarily and accounting
info being all wrong. Instead, additional routing must take into account
the new sk, just as __ip_queue_xmit() notes.

So, this commit addresses the problem by fishing the correct sk out of
state->sk -- it's already set properly in the call to nf_hook() in
__ip_local_out(), which receives the sk as part of its normal
functionality. So we make sure to plumb state->sk through the various
route_me_harder functions, and then make correct use of it following the
example of __ip_queue_xmit().

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jason A. Donenfeld 
Reviewed-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin