Ensure the match happens in the right direction, previously the
destination used was the server, not the NAT host, as the comment
shows the code intended.
Additionally nf_nat_irc uses port 0 as a signal and there's no valid way
it can appear in a DCC message, so consider port 0 also forged.
Fixes: 869f37d8e4 ("[NETFILTER]: nf_conntrack/nf_nat: add IRC helper port")
Signed-off-by: David Leadbeater <dgl@dgl.cx>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
__nf_ct_try_assign_helper() remains in place but it now requires a
template to configure the helper.
A toggle to disable automatic helper assignment was added by:
a900689264 ("netfilter: nf_ct_helper: allow to disable automatic helper assignment")
in 2012 to address the issues described in "Secure use of iptables and
connection tracking helpers". Automatic conntrack helper assignment was
disabled by:
3bb398d925 ("netfilter: nf_ct_helper: disable automatic helper assignment")
back in 2016.
This patch removes the sysctl and modparam toggles, users now have to
rely on explicit conntrack helper configuration via ruleset.
Update tools/testing/selftests/netfilter/nft_conntrack_helper.sh to
check that auto-assignment does not happen anymore.
Acked-by: Aaron Conole <aconole@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
1) Fix crash with malformed ebtables blob which do not provide all
entry points, from Florian Westphal.
2) Fix possible TCP connection clogging up with default 5-days
timeout in conntrack, from Florian.
3) Fix crash in nf_tables tproxy with unsupported chains, also from Florian.
4) Do not allow to update implicit chains.
5) Make table handle allocation per-netns to fix data race.
6) Do not truncated payload length and offset, and checksum offset.
Instead report EINVAl.
7) Enable chain stats update via static key iff no error occurs.
8) Restrict osf expression to ip, ip6 and inet families.
9) Restrict tunnel expression to netdev family.
10) Fix crash when trying to bind again an already bound chain.
11) Flowtable garbage collector might leave behind pending work to
delete entries. This patch comes with a previous preparation patch
as dependency.
12) Allow net.netfilter.nf_conntrack_frag6_high_thresh to be lowered,
from Eric Dumazet.
* git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nf_defrag_ipv6: allow nf_conntrack_frag6_high_thresh increases
netfilter: flowtable: fix stuck flows on cleanup due to pending work
netfilter: flowtable: add function to invoke garbage collection immediately
netfilter: nf_tables: disallow binding to already bound chain
netfilter: nft_tunnel: restrict it to netdev family
netfilter: nft_osf: restrict osf to ipv4, ipv6 and inet families
netfilter: nf_tables: do not leave chain stats enabled on error
netfilter: nft_payload: do not truncate csum_offset and csum_type
netfilter: nft_payload: report ERANGE for too long offset and length
netfilter: nf_tables: make table handle allocation per-netns friendly
netfilter: nf_tables: disallow updates of implicit chain
netfilter: nft_tproxy: restrict to prerouting hook
netfilter: conntrack: work around exceeded receive window
netfilter: ebtables: reject blobs that don't provide all entry points
====================
Link: https://lore.kernel.org/r/20220824220330.64283-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
While reading sysctl_[rw]mem_(max|default), they can be changed
concurrently. Thus, we need to add READ_ONCE() to its readers.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
To clear the flow table on flow table free, the following sequence
normally happens in order:
1) gc_step work is stopped to disable any further stats/del requests.
2) All flow table entries are set to teardown state.
3) Run gc_step which will queue HW del work for each flow table entry.
4) Waiting for the above del work to finish (flush).
5) Run gc_step again, deleting all entries from the flow table.
6) Flow table is freed.
But if a flow table entry already has pending HW stats or HW add work
step 3 will not queue HW del work (it will be skipped), step 4 will wait
for the pending add/stats to finish, and step 5 will queue HW del work
which might execute after freeing of the flow table.
To fix the above, this patch flushes the pending work, then it sets the
teardown flag to all flows in the flowtable and it forces a garbage
collector run to queue work to remove the flows from hardware, then it
flushes this new pending work and (finally) it forces another garbage
collector run to remove the entry from the software flowtable.
Stack trace:
[47773.882335] BUG: KASAN: use-after-free in down_read+0x99/0x460
[47773.883634] Write of size 8 at addr ffff888103b45aa8 by task kworker/u20:6/543704
[47773.885634] CPU: 3 PID: 543704 Comm: kworker/u20:6 Not tainted 5.12.0-rc7+ #2
[47773.886745] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009)
[47773.888438] Workqueue: nf_ft_offload_del flow_offload_work_handler [nf_flow_table]
[47773.889727] Call Trace:
[47773.890214] dump_stack+0xbb/0x107
[47773.890818] print_address_description.constprop.0+0x18/0x140
[47773.892990] kasan_report.cold+0x7c/0xd8
[47773.894459] kasan_check_range+0x145/0x1a0
[47773.895174] down_read+0x99/0x460
[47773.899706] nf_flow_offload_tuple+0x24f/0x3c0 [nf_flow_table]
[47773.907137] flow_offload_work_handler+0x72d/0xbe0 [nf_flow_table]
[47773.913372] process_one_work+0x8ac/0x14e0
[47773.921325]
[47773.921325] Allocated by task 592159:
[47773.922031] kasan_save_stack+0x1b/0x40
[47773.922730] __kasan_kmalloc+0x7a/0x90
[47773.923411] tcf_ct_flow_table_get+0x3cb/0x1230 [act_ct]
[47773.924363] tcf_ct_init+0x71c/0x1156 [act_ct]
[47773.925207] tcf_action_init_1+0x45b/0x700
[47773.925987] tcf_action_init+0x453/0x6b0
[47773.926692] tcf_exts_validate+0x3d0/0x600
[47773.927419] fl_change+0x757/0x4a51 [cls_flower]
[47773.928227] tc_new_tfilter+0x89a/0x2070
[47773.936652]
[47773.936652] Freed by task 543704:
[47773.937303] kasan_save_stack+0x1b/0x40
[47773.938039] kasan_set_track+0x1c/0x30
[47773.938731] kasan_set_free_info+0x20/0x30
[47773.939467] __kasan_slab_free+0xe7/0x120
[47773.940194] slab_free_freelist_hook+0x86/0x190
[47773.941038] kfree+0xce/0x3a0
[47773.941644] tcf_ct_flow_table_cleanup_work
Original patch description and stack trace by Paul Blakey.
Fixes: c29f74e0df ("netfilter: nf_flow_table: hardware offload support")
Reported-by: Paul Blakey <paulb@nvidia.com>
Tested-by: Paul Blakey <paulb@nvidia.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Only allow to use this expression from NFPROTO_NETDEV family.
Fixes: af308b94a2 ("netfilter: nf_tables: add tunnel support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
As it was originally intended, restrict extension to supported families.
Fixes: b96af92d6e ("netfilter: nf_tables: implement Passive OS fingerprint module in nft_osf")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Error might occur later in the nf_tables_addchain() codepath, enable
static key only after transaction has been created.
Fixes: 9f08ea8481 ("netfilter: nf_tables: keep chain counters away from hot path")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead report ERANGE if csum_offset is too long, and EOPNOTSUPP if type
is not support.
Fixes: 7ec3f7b47b ("netfilter: nft_payload: add packet mangling support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of offset and length are truncation to u8, report ERANGE.
Fixes: 96518518cc ("netfilter: add nftables")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
TPROXY is only allowed from prerouting, but nft_tproxy doesn't check this.
This fixes a crash (null dereference) when using tproxy from e.g. output.
Fixes: 4ed8eb6570 ("netfilter: nf_tables: Add native tproxy support")
Reported-by: Shell Chen <xierch@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
When a TCP sends more bytes than allowed by the receive window, all future
packets can be marked as invalid.
This can clog up the conntrack table because of 5-day default timeout.
Sequence of packets:
01 initiator > responder: [S], seq 171, win 5840, options [mss 1330,sackOK,TS val 63 ecr 0,nop,wscale 1]
02 responder > initiator: [S.], seq 33211, ack 172, win 65535, options [mss 1460,sackOK,TS val 010 ecr 63,nop,wscale 8]
03 initiator > responder: [.], ack 33212, win 2920, options [nop,nop,TS val 068 ecr 010], length 0
04 initiator > responder: [P.], seq 172:240, ack 33212, win 2920, options [nop,nop,TS val 279 ecr 010], length 68
Window is 5840 starting from 33212 -> 39052.
05 responder > initiator: [.], ack 240, win 256, options [nop,nop,TS val 872 ecr 279], length 0
06 responder > initiator: [.], seq 33212:34530, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
This is fine, conntrack will flag the connection as having outstanding
data (UNACKED), which lowers the conntrack timeout to 300s.
07 responder > initiator: [.], seq 34530:35848, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
08 responder > initiator: [.], seq 35848:37166, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
09 responder > initiator: [.], seq 37166:38484, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
10 responder > initiator: [.], seq 38484:39802, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 1318
Packet 10 is already sending more than permitted, but conntrack doesn't
validate this (only seq is tested vs. maxend, not 'seq+len').
38484 is acceptable, but only up to 39052, so this packet should
not have been sent (or only 568 bytes, not 1318).
At this point, connection is still in '300s' mode.
Next packet however will get flagged:
11 responder > initiator: [P.], seq 39802:40128, ack 240, win 256, options [nop,nop,TS val 892 ecr 279], length 326
nf_ct_proto_6: SEQ is over the upper bound (over the window of the receiver) .. LEN=378 .. SEQ=39802 ACK=240 ACK PSH ..
Now, a couple of replies/acks comes in:
12 initiator > responder: [.], ack 34530, win 4368,
[.. irrelevant acks removed ]
16 initiator > responder: [.], ack 39802, win 8712, options [nop,nop,TS val 296201291 ecr 2982371892], length 0
This ack is significant -- this acks the last packet send by the
responder that conntrack considered valid.
This means that ack == td_end. This will withdraw the
'unacked data' flag, the connection moves back to the 5-day timeout
of established conntracks.
17 initiator > responder: ack 40128, win 10030, ...
This packet is also flagged as invalid.
Because conntrack only updates state based on packets that are
considered valid, packet 11 'did not exist' and that gets us:
nf_ct_proto_6: ACK is over upper bound 39803 (ACKed data not seen yet) .. SEQ=240 ACK=40128 WINDOW=10030 RES=0x00 ACK URG
Because this received and processed by the endpoints, the conntrack entry
remains in a bad state, no packets will ever be considered valid again:
30 responder > initiator: [F.], seq 40432, ack 2045, win 391, ..
31 initiator > responder: [.], ack 40433, win 11348, ..
32 initiator > responder: [F.], seq 2045, ack 40433, win 11348 ..
... all trigger 'ACK is over bound' test and we end up with
non-early-evictable 5-day default timeout.
NB: This patch triggers a bunch of checkpatch warnings because of silly
indent. I will resend the cleanup series linked below to reduce the
indent level once this change has propagated to net-next.
I could route the cleanup via nf but that causes extra backport work for
stable maintainers.
Link: https://lore.kernel.org/netfilter-devel/20220720175228.17880-1-fw@strlen.de/T/#mb1d7147d36294573cc4f81d00f9f8dadfdd06cd8
Signed-off-by: Florian Westphal <fw@strlen.de>
NF_CONNTRACK_PROCFS was marked obsolete in commit 54b07dca68
("netfilter: provide config option to disable ancient procfs parts") in
v3.3.
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Since f3a2181e16 ("netfilter: nf_tables: Support for sets with
multiple ranged fields"), it possible to combine intervals and
concatenations. Later on, ef516e8625 ("netfilter: nf_tables:
reintroduce the NFT_SET_CONCAT flag") provides the NFT_SET_CONCAT flag
for userspace to report that the set stores a concatenation.
Make sure NFT_SET_CONCAT is set on if field_count is specified for
consistency. Otherwise, if NFT_SET_CONCAT is specified with no
field_count, bail out with EINVAL.
Fixes: ef516e8625 ("netfilter: nf_tables: reintroduce the NFT_SET_CONCAT flag")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These flags are mutually exclusive, report EINVAL in this case.
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the NFT_SET_CONCAT|NFT_SET_INTERVAL flags are set on, then the
netlink attribute NFTA_SET_ELEM_KEY_END must be specified. Otherwise,
NFTA_SET_ELEM_KEY_END should not be present.
For catch-all element, NFTA_SET_ELEM_KEY_END should not be present.
The NFT_SET_ELEM_INTERVAL_END is never used with this set flags
combination.
Fixes: 7b225d0b5c ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
If the NFTA_SET_ELEM_OBJREF netlink attribute is present and
NFT_SET_OBJECT flag is set on, report EINVAL.
Move existing sanity check earlier to validate that NFT_SET_OBJECT
requires NFTA_SET_ELEM_OBJREF.
Fixes: 8aeff920dc ("netfilter: nf_tables: add stateful object reference to set elements")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
While looping to build the bitmap of used anonymous set names, check the
current set in the iteration, instead of the one that is being created.
Fixes: 37a9cc5255 ("netfilter: nf_tables: add generation mask to sets")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
To avoid allocation of the conntrack extension area when possible,
the default behaviour was changed to only allocate the event extension
if a userspace program is subscribed to a notification group.
Problem is that while 'conntrack -E' does enable the event allocation
behind the scenes, 'conntrack -E expect' does not: no expectation events
are delivered unless user sets
"net.netfilter.nf_conntrack_events" back to 1 (always on).
Fix the autodetection to also consider EXP type group.
We need to track the 6 event groups (3+3, new/update/destroy for events and
for expectations each) independently, else we'd disable events again
if an expectation group becomes empty while there is still an active
event group.
Fixes: 2794cdb0b9 ("netfilter: nfnetlink: allow to detect if ctnetlink listeners exist")
Reported-by: Yi Chen <yiche@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
nf_tables_check_loops() can be called from rhashtable list
walk so cond_resched() cannot be used here.
Fixes: 81ea010667 ("netfilter: nf_tables: add rescheduling points during loop detection walks")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This uses a pseudo-linearization scheme with a 64k global buffer,
but BIG TCP arrival means IPv6 TCP stack can generate skbs
that exceed this size.
In practice, IRC commands are not expected to exceed 512 bytes, plus
this is interactive protocol, so we should not see large packets
in practice.
Given most IRC connections nowadays use TLS so this helper could also be
removed in the near future.
Fixes: 7c4e983c4f ("net: allow gso_max_size to exceed 65536")
Fixes: 0fe79f28bf ("net: allow gro_max_size to exceed 65536")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This uses a pseudo-linearization scheme with a 64k global buffer,
but BIG TCP arrival means IPv6 TCP stack can generate skbs
that exceed this size.
Use skb_linearize. It should be possible to rewrite this to properly
deal with segmented skbs (i.e., only do small chunk-wise accesses),
but this is going to be a lot more intrusive than this because every
helper function needs to get the sk_buff instead of a pointer to a raw
data buffer.
In practice, provided we're really looking at FTP control channel packets,
there should never be a case where we deal with huge packets.
Fixes: 7c4e983c4f ("net: allow gso_max_size to exceed 65536")
Fixes: 0fe79f28bf ("net: allow gro_max_size to exceed 65536")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
With BIG TCP, packets generated by tcp stack may exceed 64kb.
Cap datalen at 64kb. The internal message format uses 16bit fields,
so no embedded message can exceed 64k size.
Multiple h323 messages in a single superpacket may now result
in a message to get treated as incomplete/truncated, but thats
better than scribbling past h323_buffer.
Another alternative suitable for net tree would be a switch to
skb_linearize().
Fixes: 7c4e983c4f ("net: allow gso_max_size to exceed 65536")
Fixes: 0fe79f28bf ("net: allow gro_max_size to exceed 65536")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
For historical reason this code performs pseudo linearization of skbs
via skb_header_pointer and a global 64k buffer.
With arrival of BIG TCP, packets generated by TCP stack can exceed 64kb.
Rewrite this to only extract the needed header data. This also allows
to get rid of the locking.
Fixes: 7c4e983c4f ("net: allow gso_max_size to exceed 65536")
Fixes: 0fe79f28bf ("net: allow gro_max_size to exceed 65536")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
dst->ops is set on when nft_expr_clone() fails, but module refcount has
not been bumped yet, therefore nft_expr_destroy() leads to module
reference underflow.
Fixes: 8cfd9b0f85 ("netfilter: nftables: generalize set expressions support")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
These are mutually exclusive, actually NFTA_SET_ELEM_KEY_END replaces
the flag notation.
Fixes: 7b225d0b5c ("netfilter: nf_tables: add NFTA_SET_ELEM_KEY_END attribute")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The generation ID is bumped from the commit path while holding the
mutex, however, netlink dump operations rely on RCU.
This patch also adds missing cb->base_eq initialization in
nf_tables_dump_set().
Fixes: 38e029f14a ("netfilter: nf_tables: set NLM_F_DUMP_INTR if netlink dumping is stale")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
In nf_tables_updtable, if nf_tables_table_enable returns an error,
nft_trans_destroy is called to free the transaction object.
nft_trans_destroy() calls list_del(), but the transaction was never
placed on a list -- the list head is all zeroes, this results in
a null dereference:
BUG: KASAN: null-ptr-deref in nft_trans_destroy+0x26/0x59
Call Trace:
nft_trans_destroy+0x26/0x59
nf_tables_newtable+0x4bc/0x9bc
[..]
Its sane to assume that nft_trans_destroy() can be called
on the transaction object returned by nft_trans_alloc(), so
make sure the list head is initialised.
Fixes: 55dd6f9307 ("netfilter: nf_tables: use new transaction infrastructure to handle table")
Reported-by: mingi cho <mgcho.minic@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Extend struct nft_data_desc to add a flag field that specifies
nft_data_init() is being called for set element data.
Use it to disallow jump to implicit chain from set element, only jump
to chain via immediate expression is allowed.
Fixes: d0e2c7de92 ("netfilter: nf_tables: add NFT_CHAIN_BINDING")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Instead of parsing the data and then validate that type and length are
correct, pass a description of the expected data so it can be validated
upfront before parsing it to bail out earlier.
This patch adds a new .size field to specify the maximum size of the
data area. The .len field is optional and it is used as an input/output
field, it provides the specific length of the expected data in the input
path. If then .len field is not specified, then obtained length from the
netlink attribute is stored. This is required by cmp, bitwise, range and
immediate, which provide no netlink attribute that describes the data
length. The immediate expression uses the destination register type to
infer the expected data type.
Relying on opencoded validation of the expected data might lead to
subtle bugs as described in 7e6bc1f6ca ("netfilter: nf_tables:
stricter validation of element data").
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for rules on the same batch by using its ID, a rule from
a different chain can be used. If a rule is added to a chain but tries to
be positioned next to a rule from a different chain, it will be linked to
chain2, but the use counter on chain1 would be the one to be incremented.
When looking for rules by ID, use the chain that was used for the lookup by
name. The chain used in the context copied to the transaction needs to
match that same chain. That way, struct nft_rule does not need to get
enlarged with another member.
Fixes: 1a94e38d25 ("netfilter: nf_tables: add NFTA_RULE_ID attribute")
Fixes: 75dd48e2e4 ("netfilter: nf_tables: Support RULE_ID reference in new rule")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for chains on the same batch by using its ID, a chain
from a different table can be used. If a rule is added to a table but
refers to a chain in a different table, it will be linked to the chain in
table2, but would have expressions referring to objects in table1.
Then, when table1 is removed, the rule will not be removed as its linked to
a chain in table2. When expressions in the rule are processed or removed,
that will lead to a use-after-free.
When looking for chains by ID, use the table that was used for the lookup
by name, and only return chains belonging to that same table.
Fixes: 837830a4b4 ("netfilter: nf_tables: add NFTA_RULE_CHAIN_ID attribute")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When doing lookups for sets on the same batch by using its ID, a set from a
different table can be used.
Then, when the table is removed, a reference to the set may be kept after
the set is freed, leading to a potential use-after-free.
When looking for sets by ID, use the table that was used for the lookup by
name, and only return sets belonging to that same table.
This fixes CVE-2022-2586, also reported as ZDI-CAN-17470.
Reported-by: Team Orca of Sea Security (@seasecresponse)
Fixes: 958bee14d0 ("netfilter: nf_tables: use new transaction infrastructure to handle sets")
Signed-off-by: Thadeu Lima de Souza Cascardo <cascardo@canonical.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Update template to validate variable length extensions. This patch adds
a new .ext_len[id] field to the template to store the expected extension
length. This is used to sanity check the initialization of the variable
length extension.
Use PTR_ERR() in nft_set_elem_init() to report errors since, after this
update, there are two reason why this might fail, either because of
ENOMEM or insufficient room in the extension field (EINVAL).
Kernels up until 7e6bc1f6ca ("netfilter: nf_tables: stricter
validation of element data") allowed to copy more data to the extension
than was allocated. This ext_len field allows to validate if the
destination has the correct size as additional check.
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Remove default to 'y', this infrastructure is not fundamental for the
flowtable operational.
Add a missing dependency on CONFIG_NF_FLOW_TABLE.
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Fixes: b038177636 ("netfilter: nf_flow_table: count pending offload workqueue tasks")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
do not access info->pkt when info->trace is not 1.
nft_traceinfo is not initialized, except when tracing is enabled.
The 'nft_trace_enabled' static key cannot be used for this, we must
always check info->trace first.
Pass nft_pktinfo directly to avoid this.
Fixes: e34b9ed96c ("netfilter: nf_tables: avoid skb access on nf_stolen")
Reported-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Trying to use 'queue' statement in ingress (for example)
triggers a splat on reinject:
WARNING: CPU: 3 PID: 1345 at net/netfilter/nf_queue.c:291
... because nf_reinject cannot find the ruleset head.
The netdev family doesn't support async resume at the moment anyway,
so disallow loading such rulesets with a more appropriate
error message.
v2: add 'validate' callback and also check hook points, v1 did
allow ingress use in 'table inet', but that doesn't work either. (Pablo)
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add explicit rescheduling points during ruleset walk.
Switching to a faster algorithm is possible but this is a much
smaller change, suitable for nf tree.
Link: https://bugzilla.netfilter.org/show_bug.cgi?id=1460
Signed-off-by: Florian Westphal <fw@strlen.de>
Acked-by: Pablo Neira Ayuso <pablo@netfilter.org>
Domingo Dirutigliano and Nicola Guerrera report kernel panic when
sending nf_queue verdict with 1-byte nfta_payload attribute.
The IP/IPv6 stack pulls the IP(v6) header from the packet after the
input hook.
If user truncates the packet below the header size, this skb_pull() will
result in a malformed skb (skb->len < 0).
Fixes: 7af4cc3fa1 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink")
Reported-by: Domingo Dirutigliano <pwnzer0tt1@proton.me>
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Daniel Borkmann says:
====================
bpf-next 2022-07-22
We've added 73 non-merge commits during the last 12 day(s) which contain
a total of 88 files changed, 3458 insertions(+), 860 deletions(-).
The main changes are:
1) Implement BPF trampoline for arm64 JIT, from Xu Kuohai.
2) Add ksyscall/kretsyscall section support to libbpf to simplify tracing kernel
syscalls through kprobe mechanism, from Andrii Nakryiko.
3) Allow for livepatch (KLP) and BPF trampolines to attach to the same kernel
function, from Song Liu & Jiri Olsa.
4) Add new kfunc infrastructure for netfilter's CT e.g. to insert and change
entries, from Kumar Kartikeya Dwivedi & Lorenzo Bianconi.
5) Add a ksym BPF iterator to allow for more flexible and efficient interactions
with kernel symbols, from Alan Maguire.
6) Bug fixes in libbpf e.g. for uprobe binary path resolution, from Dan Carpenter.
7) Fix BPF subprog function names in stack traces, from Alexei Starovoitov.
8) libbpf support for writing custom perf event readers, from Jon Doron.
9) Switch to use SPDX tag for BPF helper man page, from Alejandro Colomar.
10) Fix xsk send-only sockets when in busy poll mode, from Maciej Fijalkowski.
11) Reparent BPF maps and their charging on memcg offlining, from Roman Gushchin.
12) Multiple follow-up fixes around BPF lsm cgroup infra, from Stanislav Fomichev.
13) Use bootstrap version of bpftool where possible to speed up builds, from Pu Lehui.
14) Cleanup BPF verifier's check_func_arg() handling, from Joanne Koong.
15) Make non-prealloced BPF map allocations low priority to play better with
memcg limits, from Yafang Shao.
16) Fix BPF test runner to reject zero-length data for skbs, from Zhengchao Shao.
17) Various smaller cleanups and improvements all over the place.
* https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (73 commits)
bpf: Simplify bpf_prog_pack_[size|mask]
bpf: Support bpf_trampoline on functions with IPMODIFY (e.g. livepatch)
bpf, x64: Allow to use caller address from stack
ftrace: Allow IPMODIFY and DIRECT ops on the same function
ftrace: Add modify_ftrace_direct_multi_nolock
bpf/selftests: Fix couldn't retrieve pinned program in xdp veth test
bpf: Fix build error in case of !CONFIG_DEBUG_INFO_BTF
selftests/bpf: Fix test_verifier failed test in unprivileged mode
selftests/bpf: Add negative tests for new nf_conntrack kfuncs
selftests/bpf: Add tests for new nf_conntrack kfuncs
selftests/bpf: Add verifier tests for trusted kfunc args
net: netfilter: Add kfuncs to set and change CT status
net: netfilter: Add kfuncs to set and change CT timeout
net: netfilter: Add kfuncs to allocate and insert CT
net: netfilter: Deduplicate code in bpf_{xdp,skb}_ct_lookup
bpf: Add documentation for kfuncs
bpf: Add support for forcing kfunc args to be trusted
bpf: Switch to new kfunc flags infrastructure
tools/resolve_btfids: Add support for 8-byte BTF sets
bpf: Introduce 8-byte BTF set
...
====================
Link: https://lore.kernel.org/r/20220722221218.29943-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Introduce bpf_ct_set_status and bpf_ct_change_status kfunc helpers in
order to set nf_conn field of allocated entry or update nf_conn status
field of existing inserted entry. Use nf_ct_change_status_common to
share the permitted status field changes between netlink and BPF side
by refactoring ctnetlink_change_status.
It is required to introduce two kfuncs taking nf_conn___init and nf_conn
instead of sharing one because KF_TRUSTED_ARGS flag causes strict type
checking. This would disallow passing nf_conn___init to kfunc taking
nf_conn, and vice versa. We cannot remove the KF_TRUSTED_ARGS flag as we
only want to accept refcounted pointers and not e.g. ct->master.
Hence, bpf_ct_set_* kfuncs are meant to be used on allocated CT, and
bpf_ct_change_* kfuncs are meant to be used on inserted or looked up
CT entry.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-10-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce bpf_ct_set_timeout and bpf_ct_change_timeout kfunc helpers in
order to change nf_conn timeout. This is same as ctnetlink_change_timeout,
hence code is shared between both by extracting it out to
__nf_ct_change_timeout. It is also updated to return an error when it
sees IPS_FIXED_TIMEOUT_BIT bit in ct->status, as that check was missing.
It is required to introduce two kfuncs taking nf_conn___init and nf_conn
instead of sharing one because KF_TRUSTED_ARGS flag causes strict type
checking. This would disallow passing nf_conn___init to kfunc taking
nf_conn, and vice versa. We cannot remove the KF_TRUSTED_ARGS flag as we
only want to accept refcounted pointers and not e.g. ct->master.
Apart from this, bpf_ct_set_timeout is only called for newly allocated
CT so it doesn't need to inspect the status field just yet. Sharing the
helpers even if it was possible would make timeout setting helper
sensitive to order of setting status and timeout after allocation.
Hence, bpf_ct_set_* kfuncs are meant to be used on allocated CT, and
bpf_ct_change_* kfuncs are meant to be used on inserted or looked up
CT entry.
Co-developed-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-9-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Introduce bpf_xdp_ct_alloc, bpf_skb_ct_alloc and bpf_ct_insert_entry
kfuncs in order to insert a new entry from XDP and TC programs.
Introduce bpf_nf_ct_tuple_parse utility routine to consolidate common
code.
We extract out a helper __nf_ct_set_timeout, used by the ctnetlink and
nf_conntrack_bpf code, extract it out to nf_conntrack_core, so that
nf_conntrack_bpf doesn't need a dependency on CONFIG_NF_CT_NETLINK.
Later this helper will be reused as a helper to set timeout of allocated
but not yet inserted CT entry.
The allocation functions return struct nf_conn___init instead of
nf_conn, to distinguish allocated CT from an already inserted or looked
up CT. This is later used to enforce restrictions on what kfuncs
allocated CT can be used with.
Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org>
Co-developed-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-8-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Move common checks inside the common function, and maintain the only
difference the two being how to obtain the struct net * from ctx.
No functional change intended.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Link: https://lore.kernel.org/r/20220721134245.2450-7-memxor@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
