[ Upstream commit 90918e3b64 ]
Sequence adjustment may be required for FTP traffic with PASV/EPSV modes.
due to need to re-write packet payload (IP, port) on the ftp control
connection. This can require changes to the TCP length and expected
seq / ack_seq.
The easiest way to reproduce this issue is with PASV mode.
Example ruleset:
table inet ftp_nat {
ct helper ftp_helper {
type "ftp" protocol tcp
l3proto inet
}
chain prerouting {
type filter hook prerouting priority 0; policy accept;
tcp dport 21 ct state new ct helper set "ftp_helper"
}
}
table ip nat {
chain prerouting {
type nat hook prerouting priority -100; policy accept;
tcp dport 21 dnat ip prefix to ip daddr map {
192.168.100.1 : 192.168.13.2/32 }
}
chain postrouting {
type nat hook postrouting priority 100 ; policy accept;
tcp sport 21 snat ip prefix to ip saddr map {
192.168.13.2 : 192.168.100.1/32 }
}
}
Note that the ftp helper gets assigned *after* the dnat setup.
The inverse (nat after helper assign) is handled by an existing
check in nf_nat_setup_info() and will not show the problem.
Topoloy:
+-------------------+ +----------------------------------+
| FTP: 192.168.13.2 | <-> | NAT: 192.168.13.3, 192.168.100.1 |
+-------------------+ +----------------------------------+
|
+-----------------------+
| Client: 192.168.100.2 |
+-----------------------+
ftp nat changes do not work as expected in this case:
Connected to 192.168.100.1.
[..]
ftp> epsv
EPSV/EPRT on IPv4 off.
ftp> ls
227 Entering passive mode (192,168,100,1,209,129).
421 Service not available, remote server has closed connection.
Kernel logs:
Missing nfct_seqadj_ext_add() setup call
WARNING: CPU: 1 PID: 0 at net/netfilter/nf_conntrack_seqadj.c:41
[..]
__nf_nat_mangle_tcp_packet+0x100/0x160 [nf_nat]
nf_nat_ftp+0x142/0x280 [nf_nat_ftp]
help+0x4d1/0x880 [nf_conntrack_ftp]
nf_confirm+0x122/0x2e0 [nf_conntrack]
nf_hook_slow+0x3c/0xb0
..
Fix this by adding the required extension when a conntrack helper is assigned
to a connection that has a nat binding.
Fixes: 1a64edf54f ("netfilter: nft_ct: add helper set support")
Signed-off-by: Andrii Melnychenko <a.melnychenko@vyos.io>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3d95a2e016 ]
Now that nft_setelem_flush is not called with rcu read lock held or
disabled softinterrupts anymore this can now use GFP_KERNEL too.
This is the last atomic allocation of transaction elements, so remove
all gfp_t arguments and the wrapper function.
This makes attempts to delete large sets much more reliable, before
this was prone to transient memory allocation failures.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f359b809d5 ]
Referencing a synproxy stateful object from OUTPUT hook causes kernel
crash due to infinite recursive calls:
BUG: TASK stack guard page was hit at 000000008bda5b8c (stack is 000000003ab1c4a5..00000000494d8b12)
[...]
Call Trace:
__find_rr_leaf+0x99/0x230
fib6_table_lookup+0x13b/0x2d0
ip6_pol_route+0xa4/0x400
fib6_rule_lookup+0x156/0x240
ip6_route_output_flags+0xc6/0x150
__nf_ip6_route+0x23/0x50
synproxy_send_tcp_ipv6+0x106/0x200
synproxy_send_client_synack_ipv6+0x1aa/0x1f0
nft_synproxy_do_eval+0x263/0x310
nft_do_chain+0x5a8/0x5f0 [nf_tables
nft_do_chain_inet+0x98/0x110
nf_hook_slow+0x43/0xc0
__ip6_local_out+0xf0/0x170
ip6_local_out+0x17/0x70
synproxy_send_tcp_ipv6+0x1a2/0x200
synproxy_send_client_synack_ipv6+0x1aa/0x1f0
[...]
Implement objref and objrefmap expression validate functions.
Currently, only NFT_OBJECT_SYNPROXY object type requires validation.
This will also handle a jump to a chain using a synproxy object from the
OUTPUT hook.
Now when trying to reference a synproxy object in the OUTPUT hook, nft
will produce the following error:
synproxy_crash.nft: Error: Could not process rule: Operation not supported
synproxy name mysynproxy
^^^^^^^^^^^^^^^^^^^^^^^^
Fixes: ee394f96ad ("netfilter: nft_synproxy: add synproxy stateful object support")
Reported-by: Georg Pfuetzenreuter <georg.pfuetzenreuter@suse.com>
Closes: https://bugzilla.suse.com/1250237
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit c5ba345b2d ]
ct_seq_show() has an opportunistic garbage collector :
if (nf_ct_should_gc(ct)) {
nf_ct_kill(ct);
goto release;
}
So if one nf_conn is killed there, next time ct_get_next() runs,
we skip the following item in the bucket, even if it should have
been displayed if gc did not take place.
We can decrement st->skip_elems to tell ct_get_next() one of the items
was removed from the chain.
Fixes: 58e207e498 ("netfilter: evict stale entries when user reads /proc/net/nf_conntrack")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 09efbac953 ]
During a batch replay, the nlh pointer is not reset until the parsing of
the commands. Since commit bf2ac490d2 ("netfilter: nfnetlink: Handle
ACK flags for batch messages") that is problematic as the condition to
add an ACK for batch begin will evaluate to true even if NLM_F_ACK
wasn't used for batch begin message.
If there is an error during the command processing, netlink is sending
an ACK despite that. This misleads userspace tools which think that the
return code was 0. Reset the nlh pointer to the original one when a
replay is triggered.
Fixes: bf2ac490d2 ("netfilter: nfnetlink: Handle ACK flags for batch messages")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 134121bfd9 ]
On the netns cleanup path, __ip_vs_ftp_exit() may unregister ip_vs_ftp
before connections with valid cp->app pointers are flushed, leading to a
use-after-free.
Fix this by introducing a global `exiting_module` flag, set to true in
ip_vs_ftp_exit() before unregistering the pernet subsystem. In
__ip_vs_ftp_exit(), skip ip_vs_ftp unregister if called during netns
cleanup (when exiting_module is false) and defer it to
__ip_vs_cleanup_batch(), which unregisters all apps after all connections
are flushed. If called during module exit, unregister ip_vs_ftp
immediately.
Fixes: 61b1ab4583 ("IPVS: netns, add basic init per netns.")
Suggested-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Slavin Liu <slavin452@gmail.com>
Signed-off-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 944b6b216c ]
KCSAN reported a data-race on the `ipvs->enable` flag, which is
written in the control path and read concurrently from many other
contexts.
Following a suggestion by Julian, this patch fixes the race by
converting all accesses to use `WRITE_ONCE()/READ_ONCE()`.
This lightweight approach ensures atomic access and acts as a
compiler barrier, preventing unsafe optimizations where the flag
is checked in loops (e.g., in ip_vs_est.c).
Additionally, the `enable` checks in the fast-path hooks
(`ip_vs_in_hook`, `ip_vs_out_hook`, `ip_vs_forward_icmp`) are
removed. These are unnecessary since commit 857ca89711
("ipvs: register hooks only with services"). The `enable=0`
condition they check for can only occur in two rare and non-fatal
scenarios: 1) after hooks are registered but before the flag is set,
and 2) after hooks are unregistered on cleanup_net. In the worst
case, a single packet might be mishandled (e.g., dropped), which
does not lead to a system crash or data corruption. Adding a check
in the performance-critical fast-path to handle this harmless
condition is not a worthwhile trade-off.
Fixes: 857ca89711 ("ipvs: register hooks only with services")
Reported-by: syzbot+1651b5234028c294c339@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=1651b5234028c294c339
Suggested-by: Julian Anastasov <ja@ssi.bg>
Link: https://lore.kernel.org/lvs-devel/2189fc62-e51e-78c9-d1de-d35b8e3657e3@ssi.bg/
Signed-off-by: Zhang Tengfei <zhtfdev@gmail.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ba941796d7 ]
Since the ahash_region() macro was redefined to calculate the region
index solely from HTABLE_REGION_BITS, the htable_bits parameter became
unused.
Remove the unused htable_bits argument and its call sites, simplifying
the code without changing semantics.
Fixes: 8478a729c0 ("netfilter: ipset: fix region locking in hash types")
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Reviewed-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
The hash, hash_fast, rhash and bitwise sets may indicate no result even
though a matching element exists during a short time window while other
cpu is finalizing the transaction.
This happens when the hash lookup/bitwise lookup function has picked up
the old genbit, right before it was toggled by nf_tables_commit(), but
then the same cpu managed to unlink the matching old element from the
hash table:
cpu0 cpu1
has added new elements to clone
has marked elements as being
inactive in new generation
perform lookup in the set
enters commit phase:
A) observes old genbit
increments base_seq
I) increments the genbit
II) removes old element from the set
B) finds matching element
C) returns no match: found
element is not valid in old
generation
Next lookup observes new genbit and
finds matching e2.
Consider a packet matching element e1, e2.
cpu0 processes following transaction:
1. remove e1
2. adds e2, which has same key as e1.
P matches both e1 and e2. Therefore, cpu1 should always find a match
for P. Due to above race, this is not the case:
cpu1 observed the old genbit. e2 will not be considered once it is found.
The element e1 is not found anymore if cpu0 managed to unlink it from the
hlist before cpu1 found it during list traversal.
The situation only occurs for a brief time period, lookups happening
after I) observe new genbit and return e2.
This problem exists in all set types except nft_set_pipapo, so fix it once
in nft_lookup rather than each set ops individually.
Sample the base sequence counter, which gets incremented right before the
genbit is changed.
Then, if no match is found, retry the lookup if the base sequence was
altered in between.
If the base sequence hasn't changed:
- No update took place: no-match result is expected.
This is the common case. or:
- nf_tables_commit() hasn't progressed to genbit update yet.
Old elements were still visible and nomatch result is expected, or:
- nf_tables_commit updated the genbit:
We picked up the new base_seq, so the lookup function also picked
up the new genbit, no-match result is expected.
If the old genbit was observed, then nft_lookup also picked up the old
base_seq: nft_lookup_should_retry() returns true and relookup is performed
in the new generation.
This problem was added when the unconditional synchronize_rcu() call
that followed the current/next generation bit toggle was removed.
Thanks to Pablo Neira Ayuso for reviewing an earlier version of this
patchset, for suggesting re-use of existing base_seq and placement of
the restart loop in nft_set_do_lookup().
Fixes: 0cbc06b3fa ("netfilter: nf_tables: remove synchronize_rcu in commit phase")
Signed-off-by: Florian Westphal <fw@strlen.de>
This function was added for retpoline mitigation and is replaced by a
static inline helper if mitigations are not enabled.
Enable this helper function unconditionally so next patch can add a lookup
restart mechanism to fix possible false negatives while transactions are
in progress.
Adding lookup restarts in nft_lookup_eval doesn't work as nft_objref would
then need the same copypaste loop.
This patch is separate to ease review of the actual bug fix.
Suggested-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
This will soon be read from packet path around same time as the gencursor.
Both gencursor and base_seq get incremented almost at the same time, so
it makes sense to place them in the same structure.
This doesn't increase struct net size on 64bit due to padding.
Signed-off-by: Florian Westphal <fw@strlen.de>
When the rbtree lookup function finds a match in the rbtree, it sets the
range start interval to a potentially inactive element.
Then, after tree lookup, if the matching element is inactive, it returns
NULL and suppresses a matching result.
This is wrong and leads to false negative matches when a transaction has
already entered the commit phase.
cpu0 cpu1
has added new elements to clone
has marked elements as being
inactive in new generation
perform lookup in the set
enters commit phase:
I) increments the genbit
A) observes new genbit
B) finds matching range
C) returns no match: found
range invalid in new generation
II) removes old elements from the tree
C New nft_lookup happening now
will find matching element,
because it is no longer
obscured by old, inactive one.
Consider a packet matching range r1-r2:
cpu0 processes following transaction:
1. remove r1-r2
2. add r1-r3
P is contained in both ranges. Therefore, cpu1 should always find a match
for P. Due to above race, this is not the case:
cpu1 does find r1-r2, but then ignores it due to the genbit indicating
the range has been removed. It does NOT test for further matches.
The situation persists for all lookups until after cpu0 hits II) after
which r1-r3 range start node is tested for the first time.
Move the "interval start is valid" check ahead so that tree traversal
continues if the starting interval is not valid in this generation.
Thanks to Stefan Hanreich for providing an initial reproducer for this
bug.
Reported-by: Stefan Hanreich <s.hanreich@proxmox.com>
Fixes: c1eda3c639 ("netfilter: nft_rbtree: ignore inactive matching element with no descendants")
Signed-off-by: Florian Westphal <fw@strlen.de>
The pipapo set type is special in that it has two copies of its
datastructure: one live copy containing only valid elements and one
on-demand clone used during transaction where adds/deletes happen.
This clone is not visible to the datapath.
This is unlike all other set types in nftables, those all link new
elements into their live hlist/tree.
For those sets, the lookup functions must skip the new elements while the
transaction is ongoing to ensure consistency.
As the clone is shallow, removal does have an effect on the packet path:
once the transaction enters the commit phase the 'gencursor' bit that
determines which elements are active and which elements should be ignored
(because they are no longer valid) is flipped.
This causes the datapath lookup to ignore these elements if they are found
during lookup.
This opens up a small race window where pipapo has an inconsistent view of
the dataset from when the transaction-cpu flipped the genbit until the
transaction-cpu calls nft_pipapo_commit() to swap live/clone pointers:
cpu0 cpu1
has added new elements to clone
has marked elements as being
inactive in new generation
perform lookup in the set
enters commit phase:
I) increments the genbit
A) observes new genbit
removes elements from the clone so
they won't be found anymore
B) lookup in datastructure
can't see new elements yet,
but old elements are ignored
-> Only matches elements that
were not changed in the
transaction
II) calls nft_pipapo_commit(), clone
and live pointers are swapped.
C New nft_lookup happening now
will find matching elements.
Consider a packet matching range r1-r2:
cpu0 processes following transaction:
1. remove r1-r2
2. add r1-r3
P is contained in both ranges. Therefore, cpu1 should always find a match
for P. Due to above race, this is not the case:
cpu1 does find r1-r2, but then ignores it due to the genbit indicating
the range has been removed.
At the same time, r1-r3 is not visible yet, because it can only be found
in the clone.
The situation persists for all lookups until after cpu0 hits II).
The fix is easy: Don't check the genbit from pipapo lookup functions.
This is possible because unlike the other set types, the new elements are
not reachable from the live copy of the dataset.
The clone/live pointer swap is enough to avoid matching on old elements
while at the same time all new elements are exposed in one go.
After this change, step B above returns a match in r1-r2.
This is fine: r1-r2 only becomes truly invalid the moment they get freed.
This happens after a synchronize_rcu() call and rcu read lock is held
via netfilter hook traversal (nf_hook_slow()).
Cc: Stefano Brivio <sbrivio@redhat.com>
Fixes: 3c4287f620 ("nf_tables: Add set type for arbitrary concatenation of ranges")
Signed-off-by: Florian Westphal <fw@strlen.de>
Running new 'set_flush_add_atomic_bitmap' test case for nftables.git
with CONFIG_PROVE_RCU_LIST=y yields:
net/netfilter/nft_set_bitmap.c:231 RCU-list traversed in non-reader section!!
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by nft/4008:
#0: ffff888147f79cd8 (&nft_net->commit_mutex){+.+.}-{4:4}, at: nf_tables_valid_genid+0x2f/0xd0
lockdep_rcu_suspicious+0x116/0x160
nft_bitmap_walk+0x22d/0x240
nf_tables_delsetelem+0x1010/0x1a00
..
This is a false positive, the list cannot be altered while the
transaction mutex is held, so pass the relevant argument to the iterator.
Fixes tag intentionally wrong; no point in picking this up if earlier
false-positive-fixups were not applied.
Fixes: 28b7a6b84c ("netfilter: nf_tables: avoid false-positive lockdep splats in set walker")
Signed-off-by: Florian Westphal <fw@strlen.de>
This new attribute is supposed to be used instead of NFTA_DEVICE_NAME
for simple wildcard interface specs. It holds a NUL-terminated string
representing an interface name prefix to match on.
While kernel code to distinguish full names from prefixes in
NFTA_DEVICE_NAME is simpler than this solution, reusing the existing
attribute with different semantics leads to confusion between different
versions of kernel and user space though:
* With old kernels, wildcards submitted by user space are accepted yet
silently treated as regular names.
* With old user space, wildcards submitted by kernel may cause crashes
since libnftnl expects NUL-termination when there is none.
Using a distinct attribute type sanitizes these situations as the
receiving part detects and rejects the unexpected attribute nested in
*_HOOK_DEVS attributes.
Fixes: 6d07a28950 ("netfilter: nf_tables: Support wildcard netdev hook specs")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
The helper registration return value is passed-through by module_init
callbacks which modprobe confuses with the harmless -EEXIST returned
when trying to load an already loaded module.
Make sure modprobe fails so users notice their helper has not been
registered and won't work.
Suggested-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Fixes: 12f7a50533 ("netfilter: add user-space connection tracking helper infrastructure")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Florian Westphal <fw@strlen.de>
A chain/flowtable update with duplicated devices in the same batch is
possible. Unfortunately, netdev event path only removes the first
device that is found, leaving unregistered the hook of the duplicated
device.
Check if a duplicated device exists in the transaction batch, bail out
with EEXIST in such case.
WARNING is hit when unregistering the hook:
[49042.221275] WARNING: CPU: 4 PID: 8425 at net/netfilter/core.c:340 nf_hook_entry_head+0xaa/0x150
[49042.221375] CPU: 4 UID: 0 PID: 8425 Comm: nft Tainted: G S 6.16.0+ #170 PREEMPT(full)
[...]
[49042.221382] RIP: 0010:nf_hook_entry_head+0xaa/0x150
Fixes: 78d9f48f7f ("netfilter: nf_tables: add devices to existing flowtable")
Fixes: b9703ed44f ("netfilter: nf_tables: support for adding new devices to an existing netdev chain")
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Florian Westphal <fw@strlen.de>
The estimator kthreads' affinity are defined by sysctl overwritten
preferences and applied through a plain call to the scheduler's affinity
API.
However since the introduction of managed kthreads preferred affinity,
such a practice shortcuts the kthreads core code which eventually
overwrites the target to the default unbound affinity.
Fix this with using the appropriate kthread's API.
Fixes: d1a8919758 ("kthread: Default affine kthread to its preferred NUMA node")
Signed-off-by: Frederic Weisbecker <frederic@kernel.org>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Florian Westphal <fw@strlen.de>
Blamed commit broke the check for a null scratch map:
- if (unlikely(!m || !*raw_cpu_ptr(m->scratch)))
+ if (unlikely(!raw_cpu_ptr(m->scratch)))
This should have been "if (!*raw_ ...)".
Use the pattern of the avx2 version which is more readable.
This can only be reproduced if avx2 support isn't available.
Fixes: d8d871a35c ("netfilter: nft_set_pipapo: merge pipapo_get/lookup")
Signed-off-by: Florian Westphal <fw@strlen.de>
Pablo Neira Ayuso says:
====================
Netfilter fixes for net
The following patchset contains Netfilter fixes for net:
1) Reinstantiate Florian Westphal as a Netfilter maintainer.
2) Depend on both NETFILTER_XTABLES and NETFILTER_XTABLES_LEGACY,
from Arnd Bergmann.
3) Use id to annotate last conntrack/expectation visited to resume
netlink dump, patches from Florian Westphal.
4) Fix bogus element in nft_pipapo avx2 lookup, introduced in
the last nf-next batch of updates, also from Florian.
5) Return 0 instead of recycling ret variable in
nf_conntrack_log_invalid_sysctl(), introduced in the last
nf-next batch of updates, from Dan Carpenter.
6) Fix WARN_ON_ONCE triggered by syzbot with larger cgroup level
in nft_socket.
* tag 'nf-25-08-07' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf:
netfilter: nft_socket: remove WARN_ON_ONCE with huge level value
netfilter: conntrack: clean up returns in nf_conntrack_log_invalid_sysctl()
netfilter: nft_set_pipapo: don't return bogus extension pointer
netfilter: ctnetlink: remove refcounting in expectation dumpers
netfilter: ctnetlink: fix refcount leak on table dump
netfilter: add back NETFILTER_XTABLES dependencies
MAINTAINERS: resurrect my netfilter maintainer entry
====================
Link: https://patch.msgid.link/20250807112948.1400523-1-pablo@netfilter.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
syzbot managed to reach this WARN_ON_ONCE by passing a huge level
value, remove it.
WARNING: CPU: 0 PID: 5853 at net/netfilter/nft_socket.c:220 nft_socket_init+0x2f4/0x3d0 net/netfilter/nft_socket.c:220
Reported-by: syzbot+a225fea35d7baf8dbdc3@syzkaller.appspotmail.com
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Smatch complains that these look like error paths with missing error
codes, especially the one where we return if nf_log_is_registered() is
true:
net/netfilter/nf_conntrack_standalone.c:575 nf_conntrack_log_invalid_sysctl()
warn: missing error code? 'ret'
In fact, all these return zero deliberately. Change them to return a
literal instead which helps readability as well as silencing the warning.
Fixes: e89a680466 ("netfilter: load nf_log_syslog on enabling nf_conntrack_log_invalid")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Acked-by: Lance Yang <lance.yang@linux.dev>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Dan Carpenter says:
Commit 17a20e09f0 ("netfilter: nft_set: remove one argument from
lookup and update functions") [..] leads to the following Smatch
static checker warning:
net/netfilter/nft_set_pipapo_avx2.c:1269 nft_pipapo_avx2_lookup()
error: uninitialized symbol 'ext'.
Fix this by initing ext to NULL and set it only once we've found
a match.
Fixes: 17a20e09f0 ("netfilter: nft_set: remove one argument from lookup and update functions")
Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Closes: https://lore.kernel.org/netfilter-devel/aJBzc3V5wk-yPOnH@stanley.mountain/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Same pattern as previous patch: do not keep the expectation object
alive via refcount, only store a cookie value and then use that
as the skip hint for dump resumption.
AFAICS this has the same issue as the one resolved in the conntrack
dumper, when we do
if (!refcount_inc_not_zero(&exp->use))
to increment the refcount, there is a chance that exp == last, which
causes a double-increment of the refcount and subsequent memory leak.
Fixes: cf6994c2b9 ("[NETFILTER]: nf_conntrack_netlink: sync expectation dumping with conntrack table dumping")
Fixes: e844a92843 ("netfilter: ctnetlink: allow to dump expectation per master conntrack")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
There is a reference count leak in ctnetlink_dump_table():
if (res < 0) {
nf_conntrack_get(&ct->ct_general); // HERE
cb->args[1] = (unsigned long)ct;
...
While its very unlikely, its possible that ct == last.
If this happens, then the refcount of ct was already incremented.
This 2nd increment is never undone.
This prevents the conntrack object from being released, which in turn
keeps prevents cnet->count from dropping back to 0.
This will then block the netns dismantle (or conntrack rmmod) as
nf_conntrack_cleanup_net_list() will wait forever.
This can be reproduced by running conntrack_resize.sh selftest in a loop.
It takes ~20 minutes for me on a preemptible kernel on average before
I see a runaway kworker spinning in nf_conntrack_cleanup_net_list.
One fix would to change this to:
if (res < 0) {
if (ct != last)
nf_conntrack_get(&ct->ct_general);
But this reference counting isn't needed in the first place.
We can just store a cookie value instead.
A followup patch will do the same for ctnetlink_exp_dump_table,
it looks to me as if this has the same problem and like
ctnetlink_dump_table, we only need a 'skip hint', not the actual
object so we can apply the same cookie strategy there as well.
Fixes: d205dc4079 ("[NETFILTER]: ctnetlink: fix deadlock in table dumping")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Pull bpf updates from Alexei Starovoitov:
- Remove usermode driver (UMD) framework (Thomas Weißschuh)
- Introduce Strongly Connected Component (SCC) in the verifier to
detect loops and refine register liveness (Eduard Zingerman)
- Allow 'void *' cast using bpf_rdonly_cast() and corresponding
'__arg_untrusted' for global function parameters (Eduard Zingerman)
- Improve precision for BPF_ADD and BPF_SUB operations in the verifier
(Harishankar Vishwanathan)
- Teach the verifier that constant pointer to a map cannot be NULL
(Ihor Solodrai)
- Introduce BPF streams for error reporting of various conditions
detected by BPF runtime (Kumar Kartikeya Dwivedi)
- Teach the verifier to insert runtime speculation barrier (lfence on
x86) to mitigate speculative execution instead of rejecting the
programs (Luis Gerhorst)
- Various improvements for 'veristat' (Mykyta Yatsenko)
- For CONFIG_DEBUG_KERNEL config warn on internal verifier errors to
improve bug detection by syzbot (Paul Chaignon)
- Support BPF private stack on arm64 (Puranjay Mohan)
- Introduce bpf_cgroup_read_xattr() kfunc to read xattr of cgroup's
node (Song Liu)
- Introduce kfuncs for read-only string opreations (Viktor Malik)
- Implement show_fdinfo() for bpf_links (Tao Chen)
- Reduce verifier's stack consumption (Yonghong Song)
- Implement mprog API for cgroup-bpf programs (Yonghong Song)
* tag 'bpf-next-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next: (192 commits)
selftests/bpf: Migrate fexit_noreturns case into tracing_failure test suite
selftests/bpf: Add selftest for attaching tracing programs to functions in deny list
bpf: Add log for attaching tracing programs to functions in deny list
bpf: Show precise rejected function when attaching fexit/fmod_ret to __noreturn functions
bpf: Fix various typos in verifier.c comments
bpf: Add third round of bounds deduction
selftests/bpf: Test invariants on JSLT crossing sign
selftests/bpf: Test cross-sign 64bits range refinement
selftests/bpf: Update reg_bound range refinement logic
bpf: Improve bounds when s64 crosses sign boundary
bpf: Simplify bounds refinement from s32
selftests/bpf: Enable private stack tests for arm64
bpf, arm64: JIT support for private stack
bpf: Move bpf_jit_get_prog_name() to core.c
bpf, arm64: Fix fp initialization for exception boundary
umd: Remove usermode driver framework
bpf/preload: Don't select USERMODE_DRIVER
selftests/bpf: Fix test dynptr/test_dynptr_memset_xdp_chunks failure
selftests/bpf: Fix test dynptr/test_dynptr_copy_xdp failure
selftests/bpf: Increase xdp data size for arm64 64K page size
...
The scratchmap size depends on the number of elements in the set.
For huge sets, each scratch map can easily require very large
allocations, e.g. for 100k entries each scratch map will require
close to 64kbyte of memory.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The matching algorithm has implemented thrice:
1. data path lookup, generic version
2. data path lookup, avx2 version
3. control plane lookup
Merge 1 and 3 by refactoring pipapo_get as a common helper, then make
nft_pipapo_lookup and nft_pipapo_get both call the common helper.
Aside from the code savings this has the benefit that we no longer allocate
temporary scratch maps for each control plane get and insertion operation.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This stems from a time when sets and nft_dynset resided in different kernel
modules. We can replace this with a direct call.
We could even remove both ->update and ->delete, given its only
supported by rhashtable, but on the off-chance we'll see runtime
add/delete for other types or a new set type keep that as-is for now.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Return the extension pointer instead of passing it as a function
argument to be filled in by the callee.
As-is, whenever false is returned, the extension pointer is not used.
For all set types, when true is returned, the extension pointer was set
to the matching element.
Only exception: nft_set_bitmap doesn't support extensions.
Return a pointer to a static const empty element extension container.
return false -> return NULL
return true -> return the elements' extension pointer.
This saves one function argument.
Signed-off-by: Florian Westphal <fw@strlen.de>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce NFNL_HOOK_TYPE_NFT_FLOWTABLE to distinguish flowtable hooks
from base chain ones. Nested attributes are shared with the old NFTABLES
hook info type since they fit apart from their misleading name.
Old nftables in user space will ignore this new hook type and thus
continue to print flowtable hooks just like before, e.g.:
| family netdev {
| hook ingress device test0 {
| 0000000000 nf_flow_offload_ip_hook [nf_flow_table]
| }
| }
With this patch in place and support for the new hook info type, output
becomes more useful:
| family netdev {
| hook ingress device test0 {
| 0000000000 flowtable ip mytable myft [nf_flow_table]
| }
| }
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Introduce a helper routine adding the nested attribute for use by a
second caller later.
Note how this introduces cancelling of 'nest2' for categorical reasons.
Since always followed by cancelling of the outer 'nest', it is
technically not needed.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Commit 8fa7292fee ("treewide: Switch/rename to timer_delete[_sync]()")
switched del_timer to timer_delete, but did not modify the comment for
ip_vs_conn_expire_now(). Now fix it.
Signed-off-by: WangYuli <wangyuli@uniontech.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
The seqcount xt_recseq is used to synchronize the replacement of
xt_table::private in xt_replace_table() against all readers such as
ipt_do_table()
To ensure that there is only one writer, the writing side disables
bottom halves. The sequence counter can be acquired recursively. Only the
first invocation modifies the sequence counter (signaling that a writer
is in progress) while the following (recursive) writer does not modify
the counter.
The lack of a proper locking mechanism for the sequence counter can lead
to live lock on PREEMPT_RT if the high prior reader preempts the
writer. Additionally if the per-CPU lock on PREEMPT_RT is removed from
local_bh_disable() then there is no synchronisation for the per-CPU
sequence counter.
The affected code is "just" the legacy netfilter code which is replaced
by "netfilter tables". That code can be disabled without sacrificing
functionality because everything is provided by the newer
implementation. This will only requires the usage of the "-nft" tools
instead of the "-legacy" ones.
The long term plan is to remove the legacy code so lets accelerate the
progress.
Relax dependencies on iptables legacy, replace select with depends on,
this should cause no harm to existing kernel configs and users can still
toggle IP{6}_NF_IPTABLES_LEGACY in any case.
Make EBTABLES_LEGACY, IPTABLES_LEGACY and ARPTABLES depend on
NETFILTER_XTABLES_LEGACY. Hide xt_recseq and its users,
xt_register_table() and xt_percpu_counter_alloc() behind
NETFILTER_XTABLES_LEGACY. Let NETFILTER_XTABLES_LEGACY depend on
!PREEMPT_RT.
This will break selftest expecing the legacy options enabled and will be
addressed in a following patch.
Co-developed-by: Florian Westphal <fw@strlen.de>
Co-developed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Since commit a3efd81205 ("netfilter: conntrack: move generation
seqcnt out of netns_ct") this param is unused.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
When no logger is registered, nf_conntrack_log_invalid fails to log invalid
packets, leaving users unaware of actual invalid traffic. Improve this by
loading nf_log_syslog, similar to how 'iptables -I FORWARD 1 -m conntrack
--ctstate INVALID -j LOG' triggers it.
Suggested-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Zi Li <zi.li@linux.dev>
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Add the netns field in the "nf_conntrack: table full, dropping packet"
log to help locate the specific netns when the table is full.
Signed-off-by: lvxiafei <lvxiafei@sensetime.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
A crash in conntrack was reported while trying to unlink the conntrack
entry from the hash bucket list:
[exception RIP: __nf_ct_delete_from_lists+172]
[..]
#7 [ff539b5a2b043aa0] nf_ct_delete at ffffffffc124d421 [nf_conntrack]
#8 [ff539b5a2b043ad0] nf_ct_gc_expired at ffffffffc124d999 [nf_conntrack]
#9 [ff539b5a2b043ae0] __nf_conntrack_find_get at ffffffffc124efbc [nf_conntrack]
[..]
The nf_conn struct is marked as allocated from slab but appears to be in
a partially initialised state:
ct hlist pointer is garbage; looks like the ct hash value
(hence crash).
ct->status is equal to IPS_CONFIRMED|IPS_DYING, which is expected
ct->timeout is 30000 (=30s), which is unexpected.
Everything else looks like normal udp conntrack entry. If we ignore
ct->status and pretend its 0, the entry matches those that are newly
allocated but not yet inserted into the hash:
- ct hlist pointers are overloaded and store/cache the raw tuple hash
- ct->timeout matches the relative time expected for a new udp flow
rather than the absolute 'jiffies' value.
If it were not for the presence of IPS_CONFIRMED,
__nf_conntrack_find_get() would have skipped the entry.
Theory is that we did hit following race:
cpu x cpu y cpu z
found entry E found entry E
E is expired <preemption>
nf_ct_delete()
return E to rcu slab
init_conntrack
E is re-inited,
ct->status set to 0
reply tuplehash hnnode.pprev
stores hash value.
cpu y found E right before it was deleted on cpu x.
E is now re-inited on cpu z. cpu y was preempted before
checking for expiry and/or confirm bit.
->refcnt set to 1
E now owned by skb
->timeout set to 30000
If cpu y were to resume now, it would observe E as
expired but would skip E due to missing CONFIRMED bit.
nf_conntrack_confirm gets called
sets: ct->status |= CONFIRMED
This is wrong: E is not yet added
to hashtable.
cpu y resumes, it observes E as expired but CONFIRMED:
<resumes>
nf_ct_expired()
-> yes (ct->timeout is 30s)
confirmed bit set.
cpu y will try to delete E from the hashtable:
nf_ct_delete() -> set DYING bit
__nf_ct_delete_from_lists
Even this scenario doesn't guarantee a crash:
cpu z still holds the table bucket lock(s) so y blocks:
wait for spinlock held by z
CONFIRMED is set but there is no
guarantee ct will be added to hash:
"chaintoolong" or "clash resolution"
logic both skip the insert step.
reply hnnode.pprev still stores the
hash value.
unlocks spinlock
return NF_DROP
<unblocks, then
crashes on hlist_nulls_del_rcu pprev>
In case CPU z does insert the entry into the hashtable, cpu y will unlink
E again right away but no crash occurs.
Without 'cpu y' race, 'garbage' hlist is of no consequence:
ct refcnt remains at 1, eventually skb will be free'd and E gets
destroyed via: nf_conntrack_put -> nf_conntrack_destroy -> nf_ct_destroy.
To resolve this, move the IPS_CONFIRMED assignment after the table
insertion but before the unlock.
Pablo points out that the confirm-bit-store could be reordered to happen
before hlist add resp. the timeout fixup, so switch to set_bit and
before_atomic memory barrier to prevent this.
It doesn't matter if other CPUs can observe a newly inserted entry right
before the CONFIRMED bit was set:
Such event cannot be distinguished from above "E is the old incarnation"
case: the entry will be skipped.
Also change nf_ct_should_gc() to first check the confirmed bit.
The gc sequence is:
1. Check if entry has expired, if not skip to next entry
2. Obtain a reference to the expired entry.
3. Call nf_ct_should_gc() to double-check step 1.
nf_ct_should_gc() is thus called only for entries that already failed an
expiry check. After this patch, once the confirmed bit check passes
ct->timeout has been altered to reflect the absolute 'best before' date
instead of a relative time. Step 3 will therefore not remove the entry.
Without this change to nf_ct_should_gc() we could still get this sequence:
1. Check if entry has expired.
2. Obtain a reference.
3. Call nf_ct_should_gc() to double-check step 1:
4 - entry is still observed as expired
5 - meanwhile, ct->timeout is corrected to absolute value on other CPU
and confirm bit gets set
6 - confirm bit is seen
7 - valid entry is removed again
First do check 6), then 4) so the gc expiry check always picks up either
confirmed bit unset (entry gets skipped) or expiry re-check failure for
re-inited conntrack objects.
This change cannot be backported to releases before 5.19. Without
commit 8a75a2c174 ("netfilter: conntrack: remove unconfirmed list")
|= IPS_CONFIRMED line cannot be moved without further changes.
Cc: Razvan Cojocaru <rzvncj@gmail.com>
Link: https://lore.kernel.org/netfilter-devel/20250627142758.25664-1-fw@strlen.de/
Link: https://lore.kernel.org/netfilter-devel/4239da15-83ff-4ca4-939d-faef283471bb@gmail.com/
Fixes: 1397af5bfd ("netfilter: conntrack: remove the percpu dying list")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This reverts commit 465b9ee0ee.
Such notifications fit better into core or nfnetlink_hook code,
following the NFNL_MSG_HOOK_GET message format.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Its a kernel implementation detail, at least at this time:
We can later decide to revert this patch if there is a compelling
reason, but then we should also remove the ifdef that prevents exposure
of ip_conntrack_status enum IPS_NAT_CLASH value in the uapi header.
Clash entries are not included in dumps (true for both old /proc
and ctnetlink) either. So for now exclude the clash bit when dumping.
Fixes: 7e5c6aa67e ("netfilter: nf_tables: add packets conntrack state to debug trace info")
Link: https://lore.kernel.org/netfilter-devel/aGwf3dCggwBlRKKC@strlen.de/
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
It's needed to check the return value of lockdep_commit_lock_is_held(),
otherwise there's no point in this assertion as it doesn't print any
debug information on itself.
Found by Linux Verification Center (linuxtesting.org) with Svace static
analysis tool.
Fixes: b04df3da1b ("netfilter: nf_tables: do not defer rule destruction via call_rcu")
Reported-by: Alexey Khoroshilov <khoroshilov@ispras.ru>
Signed-off-by: Fedor Pchelkin <pchelkin@ispras.ru>
Acked-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Restore commit 28339b21a3 ("netfilter: nf_tables: do not send complete
notification of deletions") and fix it:
- Avoid upfront modification of 'event' variable so the conditionals
become effective.
- Always include NFTA_OBJ_TYPE attribute in object notifications, user
space requires it for proper deserialisation.
- Catch DESTROY events, too.
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
This practically reverts commit 28339b21a3 ("netfilter: nf_tables: do
not send complete notification of deletions"): The feature was never
effective, due to prior modification of 'event' variable the conditional
early return never happened.
User space also relies upon the current behaviour, so better reintroduce
the shortened deletion notifications once it is fixed.
Fixes: 28339b21a3 ("netfilter: nf_tables: do not send complete notification of deletions")
Signed-off-by: Phil Sutter <phil@nwl.cc>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
