net/netfilter/nft_fwd_netdev.c: In function ‘nft_fwd_netdev_eval’:
net/netfilter/nft_fwd_netdev.c:32:10: error: ‘struct sk_buff’ has no member named ‘tc_redirected’
pkt->skb->tc_redirected = 1;
^~
net/netfilter/nft_fwd_netdev.c:33:10: error: ‘struct sk_buff’ has no member named ‘tc_from_ingress’
pkt->skb->tc_from_ingress = 1;
^~
To avoid a direct dependency with tc actions from netfilter, wrap the
redirect bits around CONFIG_NET_REDIRECT and move helpers to
include/linux/skbuff.h. Turn on this toggle from the ifb driver, the
only existing client of these bits in the tree.
This patch adds skb_set_redirected() that sets on the redirected bit
on the skbuff, it specifies if the packet was redirect from ingress
and resets the timestamp (timestamp reset was originally missing in the
netfilter bugfix).
Fixes: bcfabee1af ("netfilter: nft_fwd_netdev: allow to redirect to ifb via ingress")
Reported-by: noreply@ellerman.id.au
Reported-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Set skb->tc_redirected to 1, otherwise the ifb driver drops the packet.
Set skb->tc_from_ingress to 1 to reinject the packet back to the ingress
path after leaving the ifb egress path.
This patch inconditionally sets on these two skb fields that are
meaningful to the ifb driver. The existing forward action is guaranteed
to run from ingress path.
Fixes: 39e6dea28a ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Make sure the forward action is only used from ingress.
Fixes: 39e6dea28a ("netfilter: nf_tables: add forward expression to the netdev family")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
...and return -ENOTEMPTY to the front-end in this case, instead of
proceeding. Currently, nft takes care of checking for these cases
and not sending them to the kernel, but if we drop the set_overlap()
call in nft we can end up in situations like:
# nft add table t
# nft add set t s '{ type inet_service ; flags interval ; }'
# nft add element t s '{ 1 - 5 }'
# nft add element t s '{ 6 - 10 }'
# nft add element t s '{ 4 - 7 }'
# nft list set t s
table ip t {
set s {
type inet_service
flags interval
elements = { 1-3, 4-5, 6-7 }
}
}
This change has the primary purpose of making the behaviour
consistent with nft_set_pipapo, but is also functional to avoid
inconsistent behaviour if userspace sends overlapping elements for
any reason.
v2: When we meet the same key data in the tree, as start element while
inserting an end element, or as end element while inserting a start
element, actually check that the existing element is active, before
resetting the overlap flag (Pablo Neira Ayuso)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Replace negations of nft_rbtree_interval_end() with a new helper,
nft_rbtree_interval_start(), wherever this helps to visualise the
problem at hand, that is, for all the occurrences except for the
comparison against given flags in __nft_rbtree_get().
This gets especially useful in the next patch.
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
...and return -ENOTEMPTY to the front-end on collision, -EEXIST if
an identical element already exists. Together with the previous patch,
element collision will now be returned to the user as -EEXIST.
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Currently, the -EEXIST return code of ->insert() callbacks is ambiguous: it
might indicate that a given element (including intervals) already exists as
such, or that the new element would clash with existing ones.
If identical elements already exist, the front-end is ignoring this without
returning error, in case NLM_F_EXCL is not set. However, if the new element
can't be inserted due an overlap, we should report this to the user.
To this purpose, allow set back-ends to return -ENOTEMPTY on collision with
existing elements, translate that to -EEXIST, and return that to userspace,
no matter if NLM_F_EXCL was set.
Reported-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nf_flow_rule_match() sets control.addr_type in key, so needs to also set
the corresponding mask. An exact match is wanted, so mask is all ones.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Freeing a flowtable with offloaded flows, the flow are deleted from
hardware but are not deleted from the flow table, leaking them,
and leaving their offload bit on.
Add a second pass of the disabled gc to delete the these flows from
the flow table before freeing it.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since pskb_may_pull may change skb->data, so we need to reload ip{v6}h at
the right place.
Fixes: a908fdec3d ("netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table")
Fixes: 7d20868717 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since nf_flow_snat_port and nf_flow_snat_ip{v6} call pskb_may_pull()
which may change skb->data, so we need to reload ip{v6}h at the right
place.
Fixes: a908fdec3d ("netfilter: nf_flow_table: move ipv6 offload hook code to nf_flow_table")
Fixes: 7d20868717 ("netfilter: nf_flow_table: move ipv4 offload hook code to nf_flow_table")
Signed-off-by: Haishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nft will loop forever if the kernel doesn't support an expression:
1. nft_expr_type_get() appends the family specific name to the module list.
2. -EAGAIN is returned to nfnetlink, nfnetlink calls abort path.
3. abort path sets ->done to true and calls request_module for the
expression.
4. nfnetlink replays the batch, we end up in nft_expr_type_get() again.
5. nft_expr_type_get attempts to append family-specific name. This
one already exists on the list, so we continue
6. nft_expr_type_get adds the generic expression name to the module
list. -EAGAIN is returned, nfnetlink calls abort path.
7. abort path encounters the family-specific expression which
has 'done' set, so it gets removed.
8. abort path requests the generic expression name, sets done to true.
9. batch is replayed.
If the expression could not be loaded, then we will end up back at 1),
because the family-specific name got removed and the cycle starts again.
Note that userspace can SIGKILL the nft process to stop the cycle, but
the desired behaviour is to return an error after the generic expr name
fails to load the expression.
Fixes: eb014de4fd ("netfilter: nf_tables: autoload modules from the abort path")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing attribute validation for tunnel source and
destination ports to the netlink policy.
Fixes: af308b94a2 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add missing attribute validation for NFTA_PAYLOAD_CSUM_FLAGS
to the netlink policy.
Fixes: 1814096980 ("netfilter: nft_payload: layer 4 checksum adjustment for pseudoheader fields")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If hook registration fails, the hooks allocated via nft_netdev_hook_alloc
need to be freed.
We can't change the goto label to 'goto 5' -- while it does fix the memleak
it does cause a warning splat from the netfilter core (the hooks were not
registered).
Fixes: 3f0465a9ef ("netfilter: nf_tables: dynamically allocate hooks per net_device in flowtables")
Reported-by: syzbot+a2ff6fa45162a5ed4dd3@syzkaller.appspotmail.com
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Without patch:
# dd if=/proc/net/ip_tables_matches # original file output
conntrack
conntrack
conntrack
recent
recent
icmp
udplite
udp
tcp
0+1 records in
0+1 records out
65 bytes copied, 5.4074e-05 s, 1.2 MB/s
# dd if=/proc/net/ip_tables_matches bs=62 skip=1
dd: /proc/net/ip_tables_matches: cannot skip to specified offset
cp <<< end of last line
tcp <<< and then unexpected whole last line once again
0+1 records in
0+1 records out
7 bytes copied, 0.000102447 s, 68.3 kB/s
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Without the patch:
# dd if=/proc/net/xt_recent/SSH # original file outpt
src=127.0.0.4 ttl: 0 last_seen: 6275444819 oldest_pkt: 1 6275444819
src=127.0.0.2 ttl: 0 last_seen: 6275438906 oldest_pkt: 1 6275438906
src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
0+1 records in
0+1 records out
204 bytes copied, 6.1332e-05 s, 3.3 MB/s
Read after lseek into middle of last line (offset 140 in example below)
generates expected end of last line and then unexpected whole last line
once again
# dd if=/proc/net/xt_recent/SSH bs=140 skip=1
dd: /proc/net/xt_recent/SSH: cannot skip to specified offset
127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
src=127.0.0.3 ttl: 0 last_seen: 6275441953 oldest_pkt: 1 6275441953
0+1 records in
0+1 records out
132 bytes copied, 6.2487e-05 s, 2.1 MB/s
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If .next function does not change position index,
following .show function will repeat output related
to current position index.
Cc: stable@vger.kernel.org
Fixes: 1f4aace60b ("fs/seq_file.c: simplify seq_file iteration code ...")
Link: https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Before releasing the global mutex, we only unlink the hashtable
from the hash list, its proc file is still not unregistered at
this point. So syzbot could trigger a race condition where a
parallel htable_create() could register the same file immediately
after the mutex is released.
Move htable_remove_proc_entry() back to mutex protection to
fix this. And, fold htable_destroy() into htable_put() to make
the code slightly easier to understand.
Reported-and-tested-by: syzbot+d195fd3b9a364ddd6731@syzkaller.appspotmail.com
Fixes: c4a3922d2d ("netfilter: xt_hashlimit: reduce hashlimit_mutex scope for htable_put()")
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Phil reports that adding elements, flushing and re-adding them
right away:
nft add table t '{ set s { type ipv4_addr . inet_service; flags interval; }; }'
nft add element t s '{ 10.0.0.1 . 22-25, 10.0.0.1 . 10-20 }'
nft flush set t s
nft add element t s '{ 10.0.0.1 . 10-20, 10.0.0.1 . 22-25 }'
triggers, almost reliably, a crash like this one:
[ 71.319848] general protection fault, probably for non-canonical address 0x6f6b6e696c2e756e: 0000 [#1] PREEMPT SMP PTI
[ 71.321540] CPU: 3 PID: 1201 Comm: kworker/3:2 Not tainted 5.6.0-rc1-00377-g2bb07f4e1d861 #192
[ 71.322746] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS ?-20190711_202441-buildvm-armv7-10.arm.fedoraproject.org-2.fc31 04/01/2014
[ 71.324430] Workqueue: events nf_tables_trans_destroy_work [nf_tables]
[ 71.325387] RIP: 0010:nft_set_elem_destroy+0xa5/0x110 [nf_tables]
[ 71.326164] Code: 89 d4 84 c0 74 0e 8b 77 44 0f b6 f8 48 01 df e8 41 ff ff ff 45 84 e4 74 36 44 0f b6 63 08 45 84 e4 74 2c 49 01 dc 49 8b 04 24 <48> 8b 40 38 48 85 c0 74 4f 48 89 e7 4c 8b
[ 71.328423] RSP: 0018:ffffc9000226fd90 EFLAGS: 00010282
[ 71.329225] RAX: 6f6b6e696c2e756e RBX: ffff88813ab79f60 RCX: ffff88813931b5a0
[ 71.330365] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88813ab79f9a
[ 71.331473] RBP: ffff88813ab79f60 R08: 0000000000000008 R09: 0000000000000000
[ 71.332627] R10: 000000000000021c R11: 0000000000000000 R12: ffff88813ab79fc2
[ 71.333615] R13: ffff88813b3adf50 R14: dead000000000100 R15: ffff88813931b8a0
[ 71.334596] FS: 0000000000000000(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000
[ 71.335780] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 71.336577] CR2: 000055ac683710f0 CR3: 000000013a222003 CR4: 0000000000360ee0
[ 71.337533] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 71.338557] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 71.339718] Call Trace:
[ 71.340093] nft_pipapo_destroy+0x7a/0x170 [nf_tables_set]
[ 71.340973] nft_set_destroy+0x20/0x50 [nf_tables]
[ 71.341879] nf_tables_trans_destroy_work+0x246/0x260 [nf_tables]
[ 71.342916] process_one_work+0x1d5/0x3c0
[ 71.343601] worker_thread+0x4a/0x3c0
[ 71.344229] kthread+0xfb/0x130
[ 71.344780] ? process_one_work+0x3c0/0x3c0
[ 71.345477] ? kthread_park+0x90/0x90
[ 71.346129] ret_from_fork+0x35/0x40
[ 71.346748] Modules linked in: nf_tables_set nf_tables nfnetlink 8021q [last unloaded: nfnetlink]
[ 71.348153] ---[ end trace 2eaa8149ca759bcc ]---
[ 71.349066] RIP: 0010:nft_set_elem_destroy+0xa5/0x110 [nf_tables]
[ 71.350016] Code: 89 d4 84 c0 74 0e 8b 77 44 0f b6 f8 48 01 df e8 41 ff ff ff 45 84 e4 74 36 44 0f b6 63 08 45 84 e4 74 2c 49 01 dc 49 8b 04 24 <48> 8b 40 38 48 85 c0 74 4f 48 89 e7 4c 8b
[ 71.350017] RSP: 0018:ffffc9000226fd90 EFLAGS: 00010282
[ 71.350019] RAX: 6f6b6e696c2e756e RBX: ffff88813ab79f60 RCX: ffff88813931b5a0
[ 71.350019] RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88813ab79f9a
[ 71.350020] RBP: ffff88813ab79f60 R08: 0000000000000008 R09: 0000000000000000
[ 71.350021] R10: 000000000000021c R11: 0000000000000000 R12: ffff88813ab79fc2
[ 71.350022] R13: ffff88813b3adf50 R14: dead000000000100 R15: ffff88813931b8a0
[ 71.350025] FS: 0000000000000000(0000) GS:ffff88813bd80000(0000) knlGS:0000000000000000
[ 71.350026] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 71.350027] CR2: 000055ac683710f0 CR3: 000000013a222003 CR4: 0000000000360ee0
[ 71.350028] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 71.350028] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 71.350030] Kernel panic - not syncing: Fatal exception
[ 71.350412] Kernel Offset: disabled
[ 71.365922] ---[ end Kernel panic - not syncing: Fatal exception ]---
which is caused by dangling elements that have been deactivated, but
never removed.
On a flush operation, nft_pipapo_walk() walks through all the elements
in the mapping table, which are then deactivated by nft_flush_set(),
one by one, and added to the commit list for removal. Element data is
then freed.
On transaction commit, nft_pipapo_remove() is called, and failed to
remove these elements, leading to the stale references in the mapping.
The first symptom of this, revealed by KASan, is a one-byte
use-after-free in subsequent calls to nft_pipapo_walk(), which is
usually not enough to trigger a panic. When stale elements are used
more heavily, though, such as double-free via nft_pipapo_destroy()
as in Phil's case, the problem becomes more noticeable.
The issue comes from that fact that, on a flush operation,
nft_pipapo_remove() won't get the actual key data via elem->key,
elements to be deleted upon commit won't be found by the lookup via
pipapo_get(), and removal will be skipped. Key data should be fetched
via nft_set_ext_key(), instead.
Reported-by: Phil Sutter <phil@nwl.cc>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Jozsef Kadlecsik says:
====================
ipset patches for nf
The first one is larger than usual, but the issue could not be solved simpler.
Also, it's a resend of the patch I submitted a few days ago, with a one line
fix on top of that: the size of the comment extensions was not taken into
account at reporting the full size of the set.
- Fix "INFO: rcu detected stall in hash_xxx" reports of syzbot
by introducing region locking and using workqueue instead of timer based
gc of timed out entries in hash types of sets in ipset.
- Fix the forceadd evaluation path - the bug was also uncovered by the syzbot.
====================
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When the forceadd option is enabled, the hash:* types should find and replace
the first entry in the bucket with the new one if there are no reuseable
(deleted or timed out) entries. However, the position index was just not set
to zero and remained the invalid -1 if there were no reuseable entries.
Reported-by: syzbot+6a86565c74ebe30aea18@syzkaller.appspotmail.com
Fixes: 23c42a403a ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
In the case of huge hash:* types of sets, due to the single spinlock of
a set the processing of the whole set under spinlock protection could take
too long.
There were four places where the whole hash table of the set was processed
from bucket to bucket under holding the spinlock:
- During resizing a set, the original set was locked to exclude kernel side
add/del element operations (userspace add/del is excluded by the
nfnetlink mutex). The original set is actually just read during the
resize, so the spinlocking is replaced with rcu locking of regions.
However, thus there can be parallel kernel side add/del of entries.
In order not to loose those operations a backlog is added and replayed
after the successful resize.
- Garbage collection of timed out entries was also protected by the spinlock.
In order not to lock too long, region locking is introduced and a single
region is processed in one gc go. Also, the simple timer based gc running
is replaced with a workqueue based solution. The internal book-keeping
(number of elements, size of extensions) is moved to region level due to
the region locking.
- Adding elements: when the max number of the elements is reached, the gc
was called to evict the timed out entries. The new approach is that the gc
is called just for the matching region, assuming that if the region
(proportionally) seems to be full, then the whole set does. We could scan
the other regions to check every entry under rcu locking, but for huge
sets it'd mean a slowdown at adding elements.
- Listing the set header data: when the set was defined with timeout
support, the garbage collector was called to clean up timed out entries
to get the correct element numbers and set size values. Now the set is
scanned to check non-timed out entries, without actually calling the gc
for the whole set.
Thanks to Florian Westphal for helping me to solve the SOFTIRQ-safe ->
SOFTIRQ-unsafe lock order issues during working on the patch.
Reported-by: syzbot+4b0e9d4ff3cf117837e5@syzkaller.appspotmail.com
Reported-by: syzbot+c27b8d5010f45c666ed1@syzkaller.appspotmail.com
Reported-by: syzbot+68a806795ac89df3aa1c@syzkaller.appspotmail.com
Fixes: 23c42a403a ("netfilter: ipset: Introduction of new commands and protocol version 7")
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
I originally used unlikely() in the if (match_only) clause, which
we hit on the mapping table for the last field in a set, to ensure
we avoid branching to the rest of for loop body, which is executed
more frequently.
However, Pablo reports, this is confusing as it gives the impression
that this is not a common case, and it's actually not the intended
usage of unlikely().
I couldn't observe any statistical difference in matching rates on
x864_64 and aarch64 without it, so just drop it.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In both insertion and lookup examples, the two element pointers
of rule mapping tables were swapped. Fix that.
Reported-by: Pablo Neira Ayuso <pablo@netfilter.org>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This patch further relaxes the need to drop an skb due to a clash with
an existing conntrack entry.
Current clash resolution handles the case where the clash occurs between
two identical entries (distinct nf_conn objects with same tuples), i.e.:
Original Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
... existing handling will discard the unconfirmed clashing entry and
makes skb->_nfct point to the existing one. The skb can then be
processed normally just as if the clash would not have existed in the
first place.
For other clashes, the skb needs to be dropped.
This frequently happens with DNS resolvers that send A and AAAA queries
back-to-back when NAT rules are present that cause packets to get
different DNAT transformations applied, for example:
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.6:5353
-m statistics --mode random ... -j DNAT --dnat-to 10.0.0.7:5353
In this case the A or AAAA query is dropped which incurs a costly
delay during name resolution.
This patch also allows this collision type:
Original Reply
existing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.6:5353
clashing: 10.2.3.4:42 -> 10.8.8.8:53 10.2.3.4:42 <- 10.0.0.7:5353
In this case, clash is in original direction -- the reply direction
is still unique.
The change makes it so that when the 2nd colliding packet is received,
the clashing conntrack is tagged with new IPS_NAT_CLASH_BIT, gets a fixed
1 second timeout and is inserted in the reply direction only.
The entry is hidden from 'conntrack -L', it will time out quickly
and it can be early dropped because it will never progress to the
ASSURED state.
To avoid special-casing the delete code path to special case
the ORIGINAL hlist_nulls node, a new helper, "hlist_nulls_add_fake", is
added so hlist_nulls_del() will work.
Example:
CPU A: CPU B:
1. 10.2.3.4:42 -> 10.8.8.8:53 (A)
2. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
3. Apply DNAT, reply changed to 10.0.0.6
4. 10.2.3.4:42 -> 10.8.8.8:53 (AAAA)
5. Apply DNAT, reply changed to 10.0.0.7
6. confirm/commit to conntrack table, no collisions
7. commit clashing entry
Reply comes in:
10.2.3.4:42 <- 10.0.0.6:5353 (A)
-> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
10.2.3.4:42 <- 10.0.0.7:5353 (AAAA)
-> Finds a conntrack, DNAT is reversed & packet forwarded to 10.2.3.4:42
The conntrack entry is deleted from table, as it has the NAT_CLASH
bit set.
In case of a retransmit from ORIGINAL dir, all further packets will get
the DNAT transformation to 10.0.0.6.
I tried to come up with other solutions but they all have worse
problems.
Alternatives considered were:
1. Confirm ct entries at allocation time, not in postrouting.
a. will cause uneccesarry work when the skb that creates the
conntrack is dropped by ruleset.
b. in case nat is applied, ct entry would need to be moved in
the table, which requires another spinlock pair to be taken.
c. breaks the 'unconfirmed entry is private to cpu' assumption:
we would need to guard all nfct->ext allocation requests with
ct->lock spinlock.
2. Make the unconfirmed list a hash table instead of a pcpu list.
Shares drawback c) of the first alternative.
3. Document this is expected and force users to rearrange their
ruleset (e.g. by using "-m cluster" instead of "-m statistics").
nft has the 'jhash' expression which can be used instead of 'numgen'.
Major drawback: doesn't fix what I consider a bug, not very realistic
and I believe its reasonable to have the existing rulesets to 'just
work'.
4. Document this is expected and force users to steer problematic
packets to the same CPU -- this would serialize the "allocate new
conntrack entry/nat table evaluation/perform nat/confirm entry", so
no race can occur. Similar drawback to 3.
Another advantage of this patch compared to 1) and 2) is that there are
no changes to the hot path; things are handled in the udp tracker and
the clash resolution path.
Cc: rcu@vger.kernel.org
Cc: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Josh Triplett <josh@joshtriplett.org>
Cc: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Followup patch will need a helper function with the 'clashing entries
refer to the identical tuple in both directions' resolution logic.
This patch will add another resolve_clash helper where loser_ct must
not be added to the dying list because it will be inserted into the
table.
Therefore this also moves the stat counters and dying-list insertion
of the losing ct.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
... so it can be re-used from clash resolution in followup patch.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
ctinfo is whats taken from the skb, i.e.
ct = nf_ct_get(skb, &ctinfo).
We do not pass 'ct' and instead re-fetch it from the skb.
Just do the same for both netns and ctinfo.
Also add a comment on what clash resolution is supposed to do.
While at it, one indent level can be removed.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
nftables test case
tests/shell/testcases/flowtable/0001flowtable_0
results in a crash. After the refactor, if we leave early via
nf_flowtable_hw_offload(), then "struct flow_block_offload" is left
in an uninitialized state, but later users assume its initialised.
Fixes: a7965d58dd ("netfilter: flowtable: add nf_flow_table_offload_cmd()")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The user-specified hashtable size is unbound, this could
easily lead to an OOM or a hung task as we hold the global
mutex while allocating and initializing the new hashtable.
Add a max value to cap both cfg->size and cfg->max, as
suggested by Florian.
Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
It is unnecessary to hold hashlimit_mutex for htable_destroy()
as it is already removed from the global hashtable and its
refcount is already zero.
Also, switch hinfo->use to refcount_t so that we don't have
to hold the mutex until it reaches zero in htable_put().
Reported-and-tested-by: syzbot+adf6c6c2be1c3a718121@syzkaller.appspotmail.com
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pull networking fixes from David Miller:
1) Use after free in rxrpc_put_local(), from David Howells.
2) Fix 64-bit division error in mlxsw, from Nathan Chancellor.
3) Make sure we clear various bits of TCP state in response to
tcp_disconnect(). From Eric Dumazet.
4) Fix netlink attribute policy in cls_rsvp, from Eric Dumazet.
5) txtimer must be deleted in stmmac suspend(), from Nicolin Chen.
6) Fix TC queue mapping in bnxt_en driver, from Michael Chan.
7) Various netdevsim fixes from Taehee Yoo (use of uninitialized data,
snapshot panics, stack out of bounds, etc.)
8) cls_tcindex changes hash table size after allocating the table, fix
from Cong Wang.
9) Fix regression in the enforcement of session ID uniqueness in l2tp.
We only have to enforce uniqueness for IP based tunnels not UDP
ones. From Ridge Kennedy.
* git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (46 commits)
gtp: use __GFP_NOWARN to avoid memalloc warning
l2tp: Allow duplicate session creation with UDP
r8152: Add MAC passthrough support to new device
net_sched: fix an OOB access in cls_tcindex
qed: Remove set but not used variable 'p_link'
tc-testing: add missing 'nsPlugin' to basic.json
tc-testing: fix eBPF tests failure on linux fresh clones
net: hsr: fix possible NULL deref in hsr_handle_frame()
netdevsim: remove unused sdev code
netdevsim: use __GFP_NOWARN to avoid memalloc warning
netdevsim: use IS_ERR instead of IS_ERR_OR_NULL for debugfs
netdevsim: fix stack-out-of-bounds in nsim_dev_debugfs_init()
netdevsim: fix panic in nsim_dev_take_snapshot_write()
netdevsim: disable devlink reload when resources are being used
netdevsim: fix using uninitialized resources
bnxt_en: Fix TC queue mapping.
bnxt_en: Fix logic that disables Bus Master during firmware reset.
bnxt_en: Fix RDMA driver failure with SRIOV after firmware reset.
bnxt_en: Refactor logic to re-enable SRIOV after firmware reset detected.
net: stmmac: Delete txtimer in suspend()
...
During the refactor this was accidently removed.
Fixes: ae29045018 ("netfilter: flowtable: add nf_flow_offload_tuple() helper")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If entries exist when freeing a hardware offload enabled table,
we queue work for hardware while running the gc iteration.
Execute it (flush) after queueing.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
On netdev down event, nf_flow_table_cleanup() is called for the relevant
device and it cleans all the tables that are on that device.
If one of those tables has hardware offload flag,
nf_flow_table_iterate_cleanup flushes hardware and then runs the gc.
But the gc can queue more hardware work, which will take time to execute.
Instead first add the work, then flush it, to execute it now.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Signed-off-by: Paul Blakey <paulb@mellanox.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Convert the uses of kvmalloc_array with __GFP_ZERO to
the equivalent kvcalloc.
Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
find_set_and_id() is called when the NFNL_SUBSYS_IPSET mutex is held.
However, in the error path there can be a follow-up recvmsg() without
the mutex held. Use the start() function of struct netlink_dump_control
instead of dump() to verify and report if the specified set does not
exist.
Thanks to Pablo Neira Ayuso for helping me to understand the subleties
of the netlink protocol.
Reported-by: syzbot+fc69d7cb21258ab4ae4d@syzkaller.appspotmail.com
Signed-off-by: Jozsef Kadlecsik <kadlec@netfilter.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This new set type allows for intervals in concatenated fields,
which are expressed in the usual way, that is, simple byte
concatenation with padding to 32 bits for single fields, and
given as ranges by specifying start and end elements containing,
each, the full concatenation of start and end values for the
single fields.
Ranges are expanded to composing netmasks, for each field: these
are inserted as rules in per-field lookup tables. Bits to be
classified are divided in 4-bit groups, and for each group, the
lookup table contains 4^2 buckets, representing all the possible
values of a bit group. This approach was inspired by the Grouper
algorithm:
http://www.cse.usf.edu/~ligatti/projects/grouper/
Matching is performed by a sequence of AND operations between
bucket values, with buckets selected according to the value of
packet bits, for each group. The result of this sequence tells
us which rules matched for a given field.
In order to concatenate several ranged fields, per-field rules
are mapped using mapping arrays, one per field, that specify
which rules should be considered while matching the next field.
The mapping array for the last field contains a reference to
the element originally inserted.
The notes in nft_set_pipapo.c cover the algorithm in deeper
detail.
A pure hash-based approach is of no use here, as ranges need
to be classified. An implementation based on "proxying" the
existing red-black tree set type, creating a tree for each
field, was considered, but deemed impractical due to the fact
that elements would need to be shared between trees, at least
as long as we want to keep UAPI changes to a minimum.
A stand-alone implementation of this algorithm is available at:
https://pipapo.lameexcu.se
together with notes about possible future optimisations
(in pipapo.c).
This algorithm was designed with data locality in mind, and can
be highly optimised for SIMD instruction sets, as the bulk of
the matching work is done with repetitive, simple bitwise
operations.
At this point, without further optimisations, nft_concat_range.sh
reports, for one AMD Epyc 7351 thread (2.9GHz, 512 KiB L1D$, 8 MiB
L2$):
TEST: performance
net,port [ OK ]
baseline (drop from netdev hook): 10190076pps
baseline hash (non-ranged entries): 6179564pps
baseline rbtree (match on first field only): 2950341pps
set with 1000 full, ranged entries: 2304165pps
port,net [ OK ]
baseline (drop from netdev hook): 10143615pps
baseline hash (non-ranged entries): 6135776pps
baseline rbtree (match on first field only): 4311934pps
set with 100 full, ranged entries: 4131471pps
net6,port [ OK ]
baseline (drop from netdev hook): 9730404pps
baseline hash (non-ranged entries): 4809557pps
baseline rbtree (match on first field only): 1501699pps
set with 1000 full, ranged entries: 1092557pps
port,proto [ OK ]
baseline (drop from netdev hook): 10812426pps
baseline hash (non-ranged entries): 6929353pps
baseline rbtree (match on first field only): 3027105pps
set with 30000 full, ranged entries: 284147pps
net6,port,mac [ OK ]
baseline (drop from netdev hook): 9660114pps
baseline hash (non-ranged entries): 3778877pps
baseline rbtree (match on first field only): 3179379pps
set with 10 full, ranged entries: 2082880pps
net6,port,mac,proto [ OK ]
baseline (drop from netdev hook): 9718324pps
baseline hash (non-ranged entries): 3799021pps
baseline rbtree (match on first field only): 1506689pps
set with 1000 full, ranged entries: 783810pps
net,mac [ OK ]
baseline (drop from netdev hook): 10190029pps
baseline hash (non-ranged entries): 5172218pps
baseline rbtree (match on first field only): 2946863pps
set with 1000 full, ranged entries: 1279122pps
v4:
- fix build for 32-bit architectures: 64-bit division needs
div_u64() (kbuild test robot <lkp@intel.com>)
v3:
- rework interface for field length specification,
NFT_SET_SUBKEY disappears and information is stored in
description
- remove scratch area to store closing element of ranges,
as elements now come with an actual attribute to specify
the upper range limit (Pablo Neira Ayuso)
- also remove pointer to 'start' element from mapping table,
closing key is now accessible via extension data
- use bytes right away instead of bits for field lengths,
this way we can also double the inner loop of the lookup
function to take care of upper and lower bits in a single
iteration (minor performance improvement)
- make it clearer that set operations are actually atomic
API-wise, but we can't e.g. implement flush() as one-shot
action
- fix type for 'dup' in nft_pipapo_insert(), check for
duplicates only in the next generation, and in general take
care of differentiating generation mask cases depending on
the operation (Pablo Neira Ayuso)
- report C implementation matching rate in commit message, so
that AVX2 implementation can be compared (Pablo Neira Ayuso)
v2:
- protect access to scratch maps in nft_pipapo_lookup() with
local_bh_disable/enable() (Florian Westphal)
- drop rcu_read_lock/unlock() from nft_pipapo_lookup(), it's
already implied (Florian Westphal)
- explain why partial allocation failures don't need handling
in pipapo_realloc_scratch(), rename 'm' to clone and update
related kerneldoc to make it clear we're not operating on
the live copy (Florian Westphal)
- add expicit check for priv->start_elem in
nft_pipapo_insert() to avoid ending up in nft_pipapo_walk()
with a NULL start element, and also zero it out in every
operation that might make it invalid, so that insertion
doesn't proceed with an invalid element (Florian Westphal)
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce a new nested netlink attribute, NFTA_SET_DESC_CONCAT, used
to specify the length of each field in a set concatenation.
This allows set implementations to support concatenation of multiple
ranged items, as they can divide the input key into matching data for
every single field. Such set implementations would be selected as
they specify support for NFT_SET_INTERVAL and allow desc->field_count
to be greater than one. Explicitly disallow this for nft_set_rbtree.
In order to specify the interval for a set entry, userspace would
include in NFTA_SET_DESC_CONCAT attributes field lengths, and pass
range endpoints as two separate keys, represented by attributes
NFTA_SET_ELEM_KEY and NFTA_SET_ELEM_KEY_END.
While at it, export the number of 32-bit registers available for
packet matching, as nftables will need this to know the maximum
number of field lengths that can be specified.
For example, "packets with an IPv4 address between 192.0.2.0 and
192.0.2.42, with destination port between 22 and 25", can be
expressed as two concatenated elements:
NFTA_SET_ELEM_KEY: 192.0.2.0 . 22
NFTA_SET_ELEM_KEY_END: 192.0.2.42 . 25
and NFTA_SET_DESC_CONCAT attribute would contain:
NFTA_LIST_ELEM
NFTA_SET_FIELD_LEN: 4
NFTA_LIST_ELEM
NFTA_SET_FIELD_LEN: 2
v4: No changes
v3: Complete rework, NFTA_SET_DESC_CONCAT instead of NFTA_SET_SUBKEY
v2: No changes
Signed-off-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add NFTA_SET_ELEM_KEY_END attribute to convey the closing element of the
interval between kernel and userspace.
This patch also adds the NFT_SET_EXT_KEY_END extension to store the
closing element value in this interval.
v4: No changes
v3: New patch
[sbrivio: refactor error paths and labels; add corresponding
nft_set_ext_type for new key; rebase]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add helper function to parse the set element key netlink attribute.
v4: No changes
v3: New patch
[sbrivio: refactor error paths and labels; use NFT_DATA_VALUE_MAXLEN
instead of sizeof(*key) in helper, value can be longer than that;
rebase]
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Missing netlink attribute sanity check for NFTA_OSF_DREG,
from Florian Westphal.
2) Use bitmap infrastructure in ipset to fix KASAN slab-out-of-bounds
reads, from Jozsef Kadlecsik.
3) Missing initial CLOSED state in new sctp connection through
ctnetlink events, from Jiri Wiesner.
4) Missing check for NFT_CHAIN_HW_OFFLOAD in nf_tables offload
indirect block infrastructure, from wenxu.
5) Add __nft_chain_type_get() to sanity check family and chain type.
6) Autoload modules from the nf_tables abort path to fix races
reported by syzbot.
7) Remove unnecessary skb->csum update on inet_proto_csum_replace16(),
from Praveen Chaudhary.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch introduces a list of pending module requests. This new module
list is composed of nft_module_request objects that contain the module
name and one status field that tells if the module has been already
loaded (the 'done' field).
In the first pass, from the preparation phase, the netlink command finds
that a module is missing on this list. Then, a module request is
allocated and added to this list and nft_request_module() returns
-EAGAIN. This triggers the abort path with the autoload parameter set on
from nfnetlink, request_module() is called and the module request enters
the 'done' state. Since the mutex is released when loading modules from
the abort phase, the module list is zapped so this is iteration occurs
over a local list. Therefore, the request_module() calls happen when
object lists are in consistent state (after fulling aborting the
transaction) and the commit list is empty.
On the second pass, the netlink command will find that it already tried
to load the module, so it does not request it again and
nft_request_module() returns 0. Then, there is a look up to find the
object that the command was missing. If the module was successfully
loaded, the command proceeds normally since it finds the missing object
in place, otherwise -ENOENT is reported to userspace.
This patch also updates nfnetlink to include the reason to enter the
abort phase, which is required for this new autoload module rationale.
Fixes: ec7470b834 ("netfilter: nf_tables: store transaction list locally while requesting module")
Reported-by: syzbot+29125d208b3dae9a7019@syzkaller.appspotmail.com
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
