Before commit 871df5007e ("netfilter: flowtable: bail out if forward
path cannot be discovered"), there was a fallback to set up a forward
path in case .ndo_fill_forward_path fails or DEV_PATH_MTK_WDMA was used.
Such fallback was used by commit d787a3e38f ("mac80211: add support
for .ndo_fill_forward_path").
One possibility is to handle DEV_PATH_MTK_WDMA from the flowtable
forward path discovery. However, this is only used internally by drivers
to retrieve mtk_wdma information to set up hardware offload. Felix
decided to use the .fill_forward_path interface for this purpose due to
the lack of a better interface at that time.
Add a new DEV_PATH_IEEE80211 path which is offered if the new ieee80211
flag is set on in the struct net_device_path_ctx to restore the
flowtable with a ieee80211 netdevice. Handle this new DEV_PATH_IEEE80211
path just like DEV_PATH_ETHERNET and DEV_PATH_DSA, ie. this is the last
netdevice in the stack.
This new ieee80211 flag is implicitly unset for mtk_ppe and airoha which
call dev_fill_forward_path() to retrieve a DEV_PATH_MTK_WDMA path.
Fixes: 871df5007e ("netfilter: flowtable: bail out if forward path cannot be discovered")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Rename NF_FLOW_HW_PENDING to NF_FLOW_PENDING and use it to inhibit the
flowtable GC worker until pending hw offload work has been completed.
Apparently, nf_flow_offload_stats() can schedule work to retrieve stats
while the flow is being removed by GC.
And this bit can also be used in a follow up patch to disable GC until
the flow has been fully added in both directions.
Revert the reordering done in commit d644b23afe ("netfilter:
flowtable: publish HW_DEAD after worker is done") to prevent a race
between GC and hw offload handler.
Fixes: 2c8897953f ("netfilter: flowtable: Add pending bit for offload work")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
As bpf_ct_set_nat_info() is not validating the NAT manipulation type a
wrong value can be passed directly to nf_nat_setup_info(). This triggers
the WARN_ON() at nf_nat_setup_info() and if panic_on_warn isn't set,
then IPS_SRC_NAT_DONE is set without adding nat_bysource and conntrack
cleanup tries to unlink an uninitialized hlist node.
Fix this by checking that NAT manipulation type is correct before
calling nf_nat_setup_info(). In addition, if the WARN_ON is hit, return
NF_DROP instead of continuing with the processing to avoid similar
situations in the future.
Reported-by: VEGA <[email protected]>
Fixes: 0fabd2aa19 ("net: netfilter: add bpf_ct_set_nat_info kfunc helper")
Signed-off-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Since nft_set_commit_update() runs set commit callbacks before processing
NEWSETELEM transactions, nft_rbtree_gc_scan() can observe elements added by
the transaction being committed.
The scan records an interval end in rbe_end without checking the element's
transaction state. A later, unrelated expired start then moves both
elements to the expired list. The synchronous GC queue can free the new end
element before the transaction subsequently activates it, causing a
use-after-free.
Only consider elements that are fully active in both generations. This
keeps transaction-state elements out of the GC scan and preserves interval
pairing across skipped elements.
KASAN reports:
BUG: KASAN: slab-use-after-free in nft_setelem_activate
nft_setelem_activate net/netfilter/nf_tables_api.c:7047
nf_tables_commit net/netfilter/nf_tables_api.c:11137
Allocated by task 130:
nft_set_elem_init net/netfilter/nf_tables_api.c:6794
nft_add_set_elem net/netfilter/nf_tables_api.c:7523
Freed by task 130:
nft_trans_gc_trans_free net/netfilter/nf_tables_api.c:10506
rcu_core kernel/rcu/tree.c:2919
Fixes: 1e3b9e1c77 ("netfilter: nf_tables: call set ops .commit when building new ruleset blob")
Reported-by: <[email protected]>
Assisted-by: LLM
Signed-off-by: Weiming Shi <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
While the IPVS SYNC protocol is not secure by design
we can still protect the backup server from messages that
can wreak havoc.
This commit addresses problems from received connection flags
or their combinations. We now drop messages as follows:
1. the NO_CPORT+TEMPLATE combination allows lookups for normal
connections to hit template which can break in many ways.
While the master does not sync connections with NO_CPORT flag,
i.e. before they are established, we still accept NO_CPORT
without TEMPLATE.
2. ONE_PACKET: it is not sent by master, so we do not
expect it in backup. Before now it was ignored by
IP_VS_CONN_F_BACKUP_MASK for protocol v1 while protocol
v0 created connections that are not hashed and dropped
immediately. Better to apply the IP_VS_CONN_F_BACKUP_MASK
also to the flags from v0 messages for consistency with v1.
Fixes: 87375ab47c ("[IPVS]: ip_vs_ftp breaks connections using persistence")
Signed-off-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
ip_vs_lblcr_new() and ip_vs_lblc_new() create cache entries for
every previously unseen destination address. The table max_size only
tells the periodic collector to reclaim entries after the cache has
already exceeded the limit. It does not reclaim entries that the
attacker continues to use.
Reject new cache entries once either table reaches max_size * 3 / 2.
The extra headroom lets the periodic collector catch up while the
existing scheduler fallback continues to use the selected destination
when cache creation fails. New traffic therefore stays serviceable
without growing the tables further.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Cc: [email protected]
Reported-by: Vega <[email protected]>
Suggested-by: Julian Anastasov <[email protected]>
Signed-off-by: Zhiling Zou <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nft_flow_offload_init() bumps the flowtable use count with
nft_use_inc() before calling nf_ct_netns_get(). When the latter
fails, the error is returned as-is and the reference is leaked.
The upper layers do not balance it either: nf_tables_newexpr()
clears expr->ops when the expression init callback fails, so the
nft_expr_more() iteration in nft_rule_expr_deactivate() and
nf_tables_rule_destroy() stops right before the failed expression
and its ->destroy callback, which would drop the reference, never
runs.
Each failed rule addition therefore leaks one flowtable reference
and the flowtable can no longer be removed: NFT_MSG_DELFLOWTABLE
keeps reporting -EBUSY even though no rule references it.
Save the nf_ct_netns_get() return value and undo the nft_use_inc()
when it fails, restoring the inc/dec pairing within
nft_flow_offload_init() itself.
Fixes: a3c90f7a23 ("netfilter: nf_tables: flow offload expression")
Reported-by: TencentOS Corvus AI <[email protected]>
Cc: [email protected]
Assisted-by: CodeBuddy:Kimi-K3
Signed-off-by: Aohan Mei <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
'Fixes' commit stopped calling ip_set_init_comment() for hash types
from kernel-side-adds (xtables .. -j SET). ip_set_init_comment() says:
"The kadt functions don't use the comment extensions in any way."
But bitmap set type calls the function from kadt cb too.
While this appears to be safe (serialized via the set spinlock), it seems
better to not call the init function either, least of all to keep
behaviour consistent.
ip_set_list calls ip_set_init_comment() only from uadt cb, it can be
kept as-is.
This was triggered by yet another LLM review, hinting that the existing
rcu_dereference_protected() cannot be downgraded to only check if the
nfnl mutex is held.
Fixes: f30415929b ("netfilter: ipset: do not update comments from kernel-side hash adds")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nft_setelem_catchall_insert() looks up duplicates with
nft_set_elem_active() only, while nft_set_catchall_lookup() and the
dump path additionally skip expired elements.
Once a catchall element with a timeout expires, this predicate drift
makes it invisible to userspace dumps, yet it still blocks
re-insertion: with NLM_F_EXCL the request fails with -EEXIST, and
without it the request reports success but silently inserts nothing.
The stale entry only goes away when the (user-tunable) gc interval
elapses, so the catchall rule may silently stop matching for an
arbitrarily long time after its first expiration.
The delete path shows the same drift: nft_setelem_catchall_deactivate()
picks the first active-next entry in the catchall list, so with an
expired entry still pending GC it retires the stale entry instead of
the fresh one, and it deactivates an element that userspace no longer
sees instead of failing with -ENOENT.
Align both walks with the lookup and dump predicates: only an element
that is active and not expired counts as a duplicate or delete
candidate, using the per-netns timestamp taken at transaction start,
in line with the set backend .insert/.deactivate and catchall GC sync
paths.
Reported-by: TencentOS Corvus AI <[email protected]>
Cc: [email protected]
Fixes: aaa31047a6 ("netfilter: nftables: add catch-all set element support")
Assisted-by: CodeBuddy:Kimi-K3
Signed-off-by: Aohan Mei <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
expect_iter_name() is invoked by nf_ct_expect_iterate_net() under
spin_lock_bh(&nf_conntrack_expect_lock). It does not hold
rcu_read_lock().
When accessing exp->helper with rcu_dereference() in syzbot's report,
lockdep warns:
=============================
WARNING: suspicious RCU usage
syzkaller #0 Not tainted
-----------------------------
net/netfilter/nf_conntrack_netlink.c:3393 suspicious rcu_dereference_check() usage!
locks held by syz-executor381/5628: 2, last CPU#1:
#0: ffffffff9aee42a0 (nfnl_subsys_ctnetlink_exp){+.+.}-{4:4},
at: nfnetlink_rcv_msg+0xa69/0x12b0
#1: ffffffff8ea74d58 (nf_conntrack_expect_lock){+...}-{3:3},
at: nf_ct_expect_iterate_net+0x38/0x180
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150
lockdep_rcu_suspicious+0x140/0x1d0
expect_iter_name+0xfb/0x100
nf_ct_expect_iterate_net+0xf2/0x180
ctnetlink_del_expect+0x45d/0x640
nfnetlink_rcv_msg+0xcc2/0x12b0
netlink_rcv_skb+0x226/0x4a0
nfnetlink_rcv+0x2b9/0x28c0
netlink_unicast+0x7bd/0x940
netlink_sendmsg+0x813/0xb40
____sys_sendmsg+0x54e/0x850
___sys_sendmsg+0x2a5/0x360
__sys_sendmsg+0x2a5/0x360
do_syscall_64+0x166/0x520
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Use rcu_dereference_protected() with lockdep_is_held() on
nf_conntrack_expect_lock instead, similar to expect_iter_me() in
nf_conntrack_helper.c.
Fixes: f017941060 ("netfilter: nf_conntrack_expect: use expect->helper")
Reported-by: [email protected]
Closes: https://lore.kernel.org/netdev/[email protected]/T/#u
Signed-off-by: Naman Gulati <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
While the outer IP header is already pulled into the skb head, we must
be careful and revalidate the embedded headers after reading them from
the skb frags to prevent possible out-of-bounds access.
One such place reported by Sashiko is ip_vs_in_icmp() where local
process can change the ihl field and after pskb_may_pull() we can see
larger value. Even if icmp_send() has checks to prevent out-of-bounds
access, play safe and add check to drop the packet if the ihl field is
changed. As the outer headers are pulled, make sure the transport
header is updated too, it was used before commit 7fcc2fe39f ("net:
icmp: avoid invalid transport header access in icmp_send tracepoint")
Fixes: f2edb9f770 ("ipvs: implement passive PMTUD for IPIP packets")
Link: https://sashiko.dev/#/patchset/20260806105211.34622-1-ja%40ssi.bg
Signed-off-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nft_synproxy_do_eval() verifies the TCP checksum before it switches on
skb->protocol. It uses nf_ip_checksum(), which constructs an IPv4
pseudo header and relies on the IPv4 header checksum when folding the
whole skb. Neither operation is valid for an IPv6 packet.
A correctly checksummed IPv6 segment can therefore fail verification
when it reaches the hook as CHECKSUM_NONE or, at NF_INET_LOCAL_IN,
CHECKSUM_COMPLETE. nft_synproxy_do_eval() returns NF_DROP before
nft_synproxy_eval_v6() can send a SYN-ACK.
nft_synproxy_validate() deliberately admits NFPROTO_IPV6 and
NFPROTO_INET, and the xtables counterpart ip6t_SYNPROXY.c already calls
nf_ip6_checksum().
Use nf_checksum() with nft_pf() so the checksum helper dispatches to the
packet family's implementation.
Fixes: ad49d86e07 ("netfilter: nf_tables: Add synproxy support")
Assisted-by: LLM
Signed-off-by: Karl Mehltretter <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
We must serialize the release notifier and the config netlink function.
A concurrent thread can issue close() which can call the release function
while unrelated socket processes UNBIND request for same portid:
Oops: general protection fault, [..]
RIP: 0010:__instance_destroy+0x60/0x210 [nfnetlink_queue]
Call Trace:
nfqnl_recv_config+0x9b0/0xdc0 [nfnetlink_queue]
nfnetlink_rcv_msg+0x7c2/0xeb0
? __pfx_nfnetlink_rcv_msg+0x10/0x10
After this, parallel UNBIND and URELEASE events are impossible.
This change isn't nice, but its the shortest fix given instances
are not refcounted and the nfnetlink config callback drops the
rcu read lock early due to need for sleeping allocations.
Fixes: 7af4cc3fa1 ("[NETFILTER]: Add "nfnetlink_queue" netfilter queue handler over nfnetlink")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
flow_offload_work_del() sets NF_FLOW_HW_DEAD before the work handler
clears NF_FLOW_HW_PENDING. Once a flow is both HW_DYING and HW_DEAD, a
concurrent garbage collection pass can remove it and schedule it for RCU
freeing.
The offload worker holds neither an RCU read lock nor a reference to the
flow. If it is preempted after publishing HW_DEAD, the RCU callback can
free the flow before the worker resumes and clears HW_PENDING, resulting
in a use-after-free.
Move HW_DEAD publication to the common worker epilogue after the pending
bit is cleared, making it the final flow access by destroy work. Order all
preceding flow accesses before publishing the bit that allows garbage
collection to free the object.
Fixes: 2c8897953f ("netfilter: flowtable: Add pending bit for offload work")
Assisted-by: Codex:gpt-5
Signed-off-by: Jérémy Jean <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nf_ct_put() releases the ct->ext area inmediately, the rcu typesafe
semantics also allow to refer to the wrong conntrack from the flowtable
datapath. Hold reference on ct until flow is released after rcu grace
period.
Add rcu_barrier() on module exit path, to ensure pending flow entries
are release before module goes away.
Fixes: 0ff90b6c20 ("netfilter: nf_flow_offload: fix use-after-free and a resource leak")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
If nf_hook_entries_insert_raw() fails, the NAT hooks get never released,
resulting in a memleak.
Postpone setting nat_proto_net->nat_hook_ops when the hooks are
registered to simplify the error path to decide whether the nat hooks
need unwinding.
Fixes: 1cd472bf03 ("netfilter: nf_nat: add nat hook register functions to nf_nat")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Currently, a netdev chain or flowtable hooked to a device prefix can be
unintentionally deleted by a control-plane request targeting an exact
device name or even a shorter one due to the usage of min() to calculate
the length to match.
Fix this by making sure an exact device match never matches a prefix and
that both the target and the candidate have the same length during
delete operation. The add and update paths retain the existing overlap
matching to prevent a single device from matching multiple hooks.
Reported-by: Wei Fang <[email protected]>
Closes: https://lore.kernel.org/netfilter-devel/CANE+tVrDeNCHQVmsqkV2ozeBqyE3GtRDMhZgsg1bhw10yGNTRQ@mail.gmail.com/
Fixes: 6d07a28950 ("netfilter: nf_tables: Support wildcard netdev hook specs")
Signed-off-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nft_nat_setup_netmap() builds the mapped address in an on-stack
union nf_inet_addr. For an IPv4 mapping it writes only the 4-byte .ip
member and the loop runs a single 32-bit iteration, but it then copies
the whole 16-byte union into range->min_addr and range->max_addr, so the
upper 12 bytes reach nf_nat_setup_info() uninitialised.
KMSAN reports an uninit-value in nf_nat_setup_info() reached from
nft_nat_eval(). The IPv6 path fills all 16 bytes and is not affected.
Zero-initialise new_addr.
Fixes: 3ff7ddb135 ("netfilter: nft_nat: add netmap support")
Signed-off-by: Theodor Arsenij Larionov Trichkine <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Pull networking fixes from Jakub Kicinski:
"Nothing too exciting, usual stream of fixes. Including fixes from
Netfilter, Bluetooth and WPAN.
Current release - new code bugs:
- Bluetooth: hci_sync: fix not setting CE length properly
- eth: enic: match mailbox replies to request numbers
Previous releases - regressions:
- tunnels: drop stale dst when building an ICMP error for PMTUD
- ipv6: null-check fib6_node before accessing in __ip6_del_rt_siblings()
(bug in the rtnl_lock -> RCU conversion)
- eth: bnxt_en:
- fix crashes on Thor2 due to OOB coalescing buffer accesses
- prevent queue stop with deferred completions
Previous releases - always broken:
- eth:
- ice: don't dereference pointers from TP_printk()
- fix OOB writes on ethtool flow rule dump in 3 drivers
- mlx5: fix FEC configuration with RS_544_514_INTERLEAVED_QUAD
- dsa: tag_brcm: legacy FCS: request needed tailroom
Misc:
- net: cap tx_queue_len at S16_MAX to prevent oversized ring alloc
- ipv6: flowlabel: cap duplicate leases per socket"
* tag 'net-7.3-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (164 commits)
selftests: tc-testing: test action batch failure cleanup
net/sched: act_api: release all action references on NEWACTION failure
openvswitch: fix wrong flag value in get_ipv6_ext_hdrs()
ipmr: account multicast table and route memory
net: phy: dp83td510: handle the active-high LED polarity mode
net: macb: initialize PTP state before registering clock
net: hsr: enable promiscuous mode on interlink port with fwd offload
ipv6: fix fib6 walker UAF on seq stop
net: stmmac: fix TX descriptor availability check for TSO traffic
net/rds: fix tcp stream corruption with large pages
net: mana: restore the XDP program pointer when pre-allocation fails
net: phy: dp83867: handle the active-high LED polarity mode
octeontx2-af: fix PF/CGX debugfs PCI bus lookup
net: net_failover: Fix the deadlock in net_failover_slave_name_change()
net: phy: mediatek-ge: disable EEE on the MT7530 PHY
tcp: reject non zerocopy devmem tx
net: ethernet: mtk_eth_soc: populate lpi_interfaces to fix EEE support
net: dsa: mt7530: populate lpi_interfaces to fix EEE support
net: hinic: fix mailbox segment buffer overflow
net: sun4i-emac: fix missing of_node_put() for phy_node
...
NLM_F_DUMP_FILTERED is only set on data elements in the conntrack dump.
But when everything is filtered out it is confusing for the user space,
since the flag is not reported anymore and it looks like the table was
empty, which may or may not be the case.
'answer_flags' were introduced precisely for this use case, and the
conntrack dump should set the flag in there in case the filtering was
applied.
This is important, for example, to be able to tell if the filters are
supported or not by the kernel without modifying the kernel state.
With the proper reporting of NLM_F_DUMP_FILTERED on NLMSG_DONE, an
application in user space can just try and dump with an arbitrary
filter without worrying that there could be no matching entry. The
reported flag will signal that the filtering was applied and therefore
supported.
Fixes: cb8aa9a3af ("netfilter: ctnetlink: add kernel side filtering for dump")
Cc: [email protected]
Signed-off-by: Ilya Maximets <[email protected]>
Reviewed-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
This feature is required to use 32bit arptables binary on 64bit kernels.
It's already off in many distributions including Debian and Fedora for
many years.
Zap arptables first, it's the most esoteric of the 4 flavors.
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Instances are refcounted. However, only memory release happens on the
1 -> 0 transition; the unlink from hashes can occur with any refcount.
Uncooperative userspace can force a situation where a queue is pending
for destruction from netlink event while a different socket with same
portid processes an UNBIND request.
With right timing, this will unhash the instance again:
Oops: general protection fault, [..]
Call Trace:
<TASK>
nfulnl_recv_config+0x31a/0xd50
nfnetlink_rcv_msg+0x7c2/0xeb0
Fixes: 0597f2680d ("[NETFILTER]: Add new "nfnetlink_log" userspace packet logging facility")
Reported-by: Eulgyu Kim <[email protected]>
Reported-by: Jaeyoung Chung <[email protected]>
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
This is another run of the Coccinelle script for converting kmalloc()
family of allocations to kmalloc_obj() via the existing rules in
scripts/coccinelle/api/kmalloc_objs.cocci
This catches both the set of kmalloc() uses added since the first
kmalloc_obj() conversions in v7.0 and adds a large group missed in the
first pass due to Coccinelle not interacting well with the cleanup.h
scoped_...() family of macros[1]. I worked around this with spatch's
"--macro-file" argument to a file with all the scoped_...() macros mapped
to Coccinelle's YACFE_ITERATOR[2] as that was the closest viable control
flow indicator I could find.
Build tested allmodconfig on x86, arm64, arm, loongarch, mips, powerpc,
riscv, and s390 with no new warnings.
Link: https://lore.kernel.org/lkml/202609021314.8A9C0B8@keescook/ [1]
Link: https://github.com/coccinelle/coccinelle/blob/master/standard.h [2]
Signed-off-by: Kees Cook <[email protected]>
nf_log_syslog and nfnetlink_log unregister their per-network namespace
operations before unregistering their global logger backends. This
leaves a window where a sysctl or netlink writer can rebind the still-
registered logger after the per-net pre-exit callback cleared the old
selection.
The race looks like this:
CPU 0 CPU 1
---- ----
unregister_pernet_subsys()
nf_log_unset(net, logger)
net->nf.nf_loggers[pf] = NULL
lock nf_log_mutex
find logger in loggers[][]
net->nf.nf_loggers[pf] = logger
unlock nf_log_mutex
nf_log_unregister(logger)
lock nf_log_mutex
loggers[pf][type] = NULL
unlock nf_log_mutex
synchronize_rcu()
module exit returns
module core frees backend memory
Later, a sysctl read or packet logging operation can dereference the
stale per-net logger pointer.
Fix this by unregistering the global logger backends before tearing down
per-net state. Once the global registrations are gone, later writers can
no longer rebind the logger. unregister_pernet_subsys() already waits
for an RCU grace period after the pre-exit callback clears the per-net
selection, while nf_log_unregister() continues to cover readers of the
global logger table.
Apply this ordering fix to both nf_log backends that combine per-net
teardown with global logger registration.
Fixes: 5b023fc8d8 ("netfilter: enable per netns support for nf_loggers")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
nf_ct_set_timeout() protects the timeout hook dereference and policy lookup
with rcu_read_lock(). cttimeout_exit(), however, unregisters the per-net
operations before it clears the hook.
This allows the following interleaving:
CPU 0 CPU 1
cttimeout_exit() nf_ct_set_timeout()
unregister_pernet_subsys() rcu_read_lock()
kfree(pernet) h = nf_ct_timeout_hook
h->timeout_find_get()
nfct_timeout_pernet()
The hook still points to ctnl_timeout_find_get() when CPU 1 looks up the
already freed per-net timeout list. KASAN reported:
BUG: KASAN: slab-use-after-free in ctnl_timeout_find_get
Read of size 8 by task poc/90
Call Trace:
ctnl_timeout_find_get+0x271/0x2a0 [nfnetlink_cttimeout]
nf_ct_set_timeout+0x7b/0x3c0
xt_ct_tg_check+0x724/0xb20
xt_check_target+0x234/0xa90
do_ipt_set_ctl+0x570/0x1270
Allocated by task 89:
__kmalloc_noprof+0x16e/0x460
ops_init+0x6d/0x420
register_pernet_operations+0x2f6/0x670
Freed by task 91:
kfree+0x131/0x390
ops_undo_list+0x3d4/0x730
unregister_pernet_operations+0x232/0x490
unregister_pernet_subsys+0x1c/0x30
cttimeout_exit+0x52/0x970 [nfnetlink_cttimeout]
Clear the hook and wait for existing readers before unregistering the
per-net operations. This blocks new policy lookups and ensures readers that
observed the hook finish before the per-net storage is freed.
Fixes: ebfbe67568 ("netfilter: cttimeout: use net_generic infra")
Cc: [email protected]
Signed-off-by: Chengfeng Ye <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
sip_skip_whitespace() returns dptr unchanged when its own loop
exhausts the buffer (dptr == limit), instead of NULL like its sibling
sip_follow_continuation() returns on its own "no more data" path.
ct_sip_get_header() only checks for NULL after calling it:
dptr = sip_skip_whitespace(dptr, limit);
if (dptr == NULL)
break;
if (*dptr != ':' || ++dptr >= limit)
break;
so a recognized header name followed only by spaces/tabs running to
the exact end of the SIP payload, with no colon, makes the very next
statement read one byte past the buffer.
Make both "no more data" outcomes return NULL, matching the
convention sip_follow_continuation() already uses and that both
existing callers already check for.
Fixes: ea45f12a27 ("[NETFILTER]: nf_conntrack_sip: parse SIP headers properly")
Signed-off-by: Joas Antonio dos Santos <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
hton_seq() expects the host-order source first and the unaligned
network-order destination second. The version 1 sync sender passes these
arguments in reverse for both sequence blocks. This leaves 24 bytes of the
kmalloc-backed message unwritten. It may disclose stale heap data and
replace the live connection sequence state with values read from the
buffer.
Pass the connection sequence state as the source and the message payload as
the destination for both blocks.
Fixes: 986a075795 ("IPVS: Backup, Change sending to Version 1 format")
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Kyle Zeng <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
IPVS sync receivers validate protocol states before creating or updating a
connection. For connection templates, however, they only log states outside
the template state range and still store the value in the connection.
A template can be returned by ordinary connection lookup. TCP and SCTP then
use the invalid state as an index into their transition tables.
Reject invalid template states in both sync protocol versions before
looking up or modifying a connection. The version 1 path handles both
IPv4 and IPv6 records.
Fixes: 275411430f ("ipvs: add assured state for conn templates")
Cc: [email protected]
Assisted-by: Codex:gpt-5.6-sol
Signed-off-by: Kyle Zeng <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
This list has been moved to per-netns, remove onstack list which is not
used anymore.
Fixes: b343ededb3 ("netfilter: nf_tables: move set_update_list to nftables per-netns")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
.commit call for sets is skipped if set->dead flag is set on, but this
flag is set on later in the commit path.
This also reintroduces the bug fixed in commit 7315dc1e12
("netfilter: nf_tables: skip set commit for deleted/destroyed sets").
Fixes: 1e3b9e1c77 ("netfilter: nf_tables: call set ops .commit when building new ruleset blob")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Both the dynset and newsetelem path clone the existing set expressions
when setting set element expressions if no override expressions are
provided. This results in a double clone, once to clone the template set
expressions then another clone on the new element. Add a flag to
annotate if userspace provides a override expression (ie. expression of
the same type of the set but different configuration), otherwise borrow
the existing expression from the set. Add conditionals to release
expression iif they represent an override. Use this new override_exprs
flag to dump the dynset expression override to userspace.
This simplifies the existing logic and it also fixes a bug with the
connlimit expression which results in a module refcount imbalance
WARNING splat when resorting on the default set expressions.
Fixes: 65038428b2 ("netfilter: nf_tables: allow to specify stateful expression in set definition")
Fixes: fca05d4d61 ("netfilter: nft_dynset: honor stateful expressions in set definition")
Reported-by: Xingyuan Mo <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Several xtables extension still use pr_err() or pr_info() without
ratelimit.
For xt_cgroup, while at this, remove redundant "xt_cgroup:" prefix
since pr_fmt is already set on.
Fixes: c38c4597e4 ("netfilter: implement xt_cgroup cgroup2 path match")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Remove pr_debug() for these xtables extensions, these have no use
these days. Still, turn pr_debug() into pr_info_ratelimited() in the
.checkentry path since this helps provide a hint via dmesg in legacy
iptables.
Exception is xt_IDLETIMER in the module init path, where pr_err() is
used.
Add missing pr_fmt() definition in xt_REDIRECT, xt_NETMAP and
xt_MASQUERADE.
Add missing \n to several pr_debug() that were translated to use
pr_info_ratelimited().
Link: https://patch.msgid.link/[email protected]/
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Since pipapo_get_avx2() uses YMM registers, execute vzeroupper before
returning from it. This is needed to avoid degrading the performance of
any later SSE code that may happen to be executed.
Fixes: 7400b06396 ("nft_set_pipapo: Introduce AVX2-based lookup implementation")
Cc: [email protected]
Signed-off-by: Eric Biggers <[email protected]>
Reviewed-by: Stefano Brivio <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Allocate the chain blob before the ruleset offload to reduce chances of
entering an inconsistent state where the offloaded ruleset in the nic
and the software ruleset differ.
Fixes: c9626a2cbd ("netfilter: nf_tables: add hardware offload support")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Replace WARN_ON_ONCE with DEBUG_NET_WARN_ON_ONCE in __nf_conncount_add.
The function handles count limit breaches safely by returning
-EOVERFLOW, so a production backtrace is not needed. This prevents
unnecessary system panics when panic_on_warn=1 is enabled in production
systems.
Signed-off-by: Fernando Fernandez Mancera <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
ip_vs_ftp_get_addrport() accumulates decimal digits into a __u16
(hport) and into unsigned char (p[]) without checking for overflow.
A crafted FTP PASV/EPSV response with an over-long port or address
octet wraps the value, so the helper configures the data connection
with a truncated port/address.
The netfilter conntrack FTP helper had the same defect, fixed in
commit 2b413fc689 ("netfilter: nf_conntrack_ftp: avoid u16
overflows"). Apply the equivalent fix here: widen the port accumulator
to u32 and reject values above 65535, and reject address octets above
255.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Joas Antonio dos Santos <[email protected]>
Acked-by: Julian Anastasov <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
The rbtree set only builds the b-search array after the new ruleset has
been published through set ops .commit.
This exposes an empty set for a short time span which results in a bogus
mismatch for the following batch:
destroy table ip x
table ip x {
...
}
The same problem also affects the pipapo set backend which also provides
a set ops .commit interface too.
This patch moves the set ops .commit call right before building and
publishing the chain blob. The commit path now performs an early
handling of the DELSETELEM command to remove stale elements from the
clone before it is published via rcu. Note that DELSETELEM notifications
are still delivered in order. NEWSETELEM commands are handled after the
set is published, since this clears the previous genbit to 1 to prepare
the element for the next control plane transaction. This comes at the
cost of one extra iteration over the transaction list.
Suggested-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
This list is used to invoke the set .commit and .abort ops for the
rbtree and pipapo to run GC on expired elements and replace the current
datastructure view by the clone. For the rbtree, this also rebuild the
datapath b-search array.
From abort path, remove the set from the update_list if it is already
bound to rule, then the rule itself takes care of releasing the set and
its elements, otherwise, memleak is possible because set ops .abort
only deals with removing the set data structure, not the elements.
This is a preparation patch to call set .commit before processing the
transaction list for the rbtree, no functional changes are intended.
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Expose expectation flags included in the NF_CT_EXPECT_MASK bitmask
only. The DEAD flag is internal, do not expose it.
Fixes: b8b09dc2bf ("netfilter: nf_conntrack_expect: use conntrack GC to reap expectations")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Consolidate the check for buggy expectations with DEAD flag on
insertion, which is called both by nf_ct_expect_related() and
nf_ct_expect_related_pair().
Fixes: e765c95faa ("netfilter: nf_conntrack_expect: bail out on insert dead expectations")
Signed-off-by: Pablo Neira Ayuso <[email protected]>
All file:line references below are against v7.2-rc4 (ac5b0e5651b1). The
trace was captured on 7.2.0-rc6-kasan72rc6 (075b74841b), where the same
lines apply.
nft_obj_notify() is exported and reached from the packet path. Its only
in-tree caller is nft_quota_obj_eval() (net/netfilter/nft_quota.c:68),
which notifies with GFP_ATOMIC while evaluating a rule for a transiting
packet, holding no mutex.
Since commit 67cc570eda ("netfilter: nf_tables: coalesce multiple
notifications into one skbuff") that notification is no longer sent
immediately. __nft_obj_notify() queues it onto nft_net->notify_list via
nft_notify_enqueue() (net/netfilter/nf_tables_api.c:1211), which is a bare
list_add_tail(). notify_list has no lock of its own
(include/net/netfilter/nf_tables.h:1951), it is serialised by commit_mutex:
the six other enqueue sites all run inside a netlink transaction, and the
drain in nft_commit_notify() (net/netfilter/nf_tables_api.c:10746) does
list_del() + kfree_skb() from nf_tables_commit() with commit_mutex held.
Sending packets through a chain that references a depleted quota object
therefore races an unlocked list_add_tail() against list_del() +
kfree_skb() on another CPU. The WRITE_ONCE(prev->next, new) in __list_add()
then stores through an sk_buff that has already been freed:
BUG: KASAN: slab-use-after-free in __nft_obj_notify+0x2c5/0x2d0
Write of size 8 at addr ff110001047183c0 by task poc/76
CPU: 0 UID: 1000 PID: 76 Comm: poc Tainted: G W 7.2.0-rc6-kasan72rc6 #4
Call Trace:
<IRQ>
__nft_obj_notify (include/linux/list.h:164 include/linux/list.h:191
net/netfilter/nf_tables_api.c:1211
net/netfilter/nf_tables_api.c:8743)
nft_quota_obj_eval (net/netfilter/nft_quota.c:68)
nft_do_chain_inet
nf_hook_slow
__ip_local_out
ip_push_pending_frames
udp_send_skb
udp_sendmsg
__x64_sys_sendto
Allocated by task 77:
__alloc_skb (net/core/skbuff.c:704)
__nft_obj_notify (include/net/netlink.h:1055
net/netfilter/nf_tables_api.c:8731)
nft_quota_obj_eval (net/netfilter/nft_quota.c:68)
nft_do_chain
Freed by task 79:
nf_tables_commit (include/linux/skbuff.h:1332
net/netfilter/nf_tables_api.c:10759
net/netfilter/nf_tables_api.c:11185)
nfnetlink_rcv_batch (net/netfilter/nfnetlink.c:574)
netlink_unicast
netlink_sendmsg
The buggy address belongs to the cache skbuff_head_cache of size 232
Queueing from the packet path is wrong even leaving the race aside:
notify_list is only drained by nft_commit_notify() from nf_tables_commit()
(:11185), so a notification enqueued outside a transaction is not sent
until some later netlink batch commits, if one ever does.
The gfp argument that nft_obj_notify() still takes is a leftover of the
pre-67cc570edaa0 behaviour, where this path called nfnetlink_send()
directly. Restore that: split the message construction out into
nft_obj_notify_alloc() and let each caller decide what to do with the skb.
nft_obj_notify(), the exported one reached from the packet path, sends it
straight away; nf_tables_obj_notify(), which runs under commit_mutex, keeps
queueing it, so transaction notifications are still coalesced.
Fixes: 67cc570eda ("netfilter: nf_tables: coalesce multiple notifications into one skbuff")
Cc: [email protected]
Reported-by: TencentOS Corvus AI <[email protected]>
Assisted-by: tencentos-corvus-ai:kimi-k3
Signed-off-by: Fourie Zhang <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Allocating mem via GFP_ATOMIC on delete is problematic, delete operations
should always succeed.
Do in-place substitution: When /cidr reaches 0 count (no more elements in
the range), move ranges stored later in the array forward and keep the
count 0 ones at the end.
INIT_CIDR() can then check count == 0 without a need to search next element
in the array.
To avoid problems on weakly ordered architectures, pack the structure so it
is only 32bit wide, then use READ/WRITE_ONCE to store both cidr and count.
atomically.
Also update comments to mention the possible presence of ignored
0-count-0-cidr structures at the end and need for seqcount.
seqcount is used to restart. This avoids bogus range misses.
Given: [0]: /29 [1]: /24
cpu1 reads slot 0. then, right after, cpu2 removes /29. count drops to 0,
so it updates array to: [0], /24, [1], /0 (count 0).
cpu1 then skips /28: slot 0 was already visited, but slot 1 already replaced.
Note that mtype_add() doesn't check mtype_add_cidr() return value.
Doing this here is useless noise as this code is extensively rewritten
in the rhashtable replacement patch.
Assisted-by: Claude:claude-sonnet-5
Fixes: 8e5fd2a55e ("netfilter: ipset: rework cidr bookkeeping")
Signed-off-by: Florian Westphal <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
NFQUEUE and nft_payload can hand packet data modified by userspace back
to the stack. Recent restrictions keep link and network headers stable,
but transport header fields can still be changed.
A packet can therefore keep the same network header and conntrack entry
while changing the transport header layout. For TCP, increasing doff can
make later helper or NAT code use a different transport-header base than
the parser used, and can make offsets point past skb->tail.
Extend NFQUEUE payload validation to check the final L4 protocol and
known base headers after IPv4 options or IPv6 extension headers. Reject
packets whose L4 protocol no longer matches an attached non-template
conntrack entry, and reject IP fragments that already have such a
conntrack entry before trying to validate transport headers. Unknown L4
protocols are left to their normal protocol handlers.
For nft payload writes, reject transport-header stores that overlap TCP
doff. nft_nh_write_ok() already rejects network-header protocol changes,
so keeping doff stable prevents nft payload writes from changing the TCP
header length underneath conntrack and helper users.
This patch is a follow up to commit df07998dfd ("netfilter: nftables:
restrict linklayer and network header writes") and commit 54f34607d1
("netfilter: nfnetlink_queue: restrict writes to network header").
Reported-by: Vega <[email protected]>
Signed-off-by: Zhiling Zou <[email protected]>
Signed-off-by: Pablo Neira Ayuso <[email protected]>
Pablo Neira Ayuso says:
====================
Netfilter updates for net
This includes an enhancement to detect ct memleaks easier via
DEBUG_NET and flowtable preparation patches for IPv4 over IPV6
and vice-versa. This also includes a fix for the nft_ct custom
expectation support.
1) Add DEBUG_NET_WARN_ON_ONCE to nf_ct_set() to spot ct memleaks.
2) Pass struct net_device_path_ctx to dev_fill_forward_path() to
make it easier to pass more parameters to this function.
From Lorenzo Bianconi.
3) Add ether_type field to net_device_path context structucture.
4) Rename tun.l3_proto field to tun.inner_proto.
5) Rename ctx.tun.proto to ctx.tun.inner_proto.
6) Store ether_type in flowtable context.
7) Move IPv4 and IPv6 xmit path to a helper function.
8) Move encapsulation header parser out of the flowtable lookup
function.
9) Rework nft_ct custom expectation support to address a possible
reallocation of ct extension area while expectation list also
contains expectations. Move datapath to a ct helper to fix it.
10) Ensure timeout is always lowered for the non-closing RST case
in the TCP connection tracking.
11) Bail out when inserting already dead expectation, this should
not ever happen, hence report it via DEBUG_NET.
12) Comestic updates for improving the conntrack selftest dump and
flush userspace program, from Qingshuang Fu.
* tag 'nf-next-26-08-10' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf-next:
selftests: netfilter: conntrack_dump_flush: remove unused variables and fix typo
netfilter: nf_conntrack_expect: bail out on insert dead expectations
netfilter: conntrack: always lower timeout for non-closing RST packets
netfilter: nft_ct: move custom expectation support to helper
netfilter: flowtable: detach layer 2 encapsulation parser from lookup
netfilter: flowtable: move ipv4 and ipv6 xmit path to function
netfilter: flowtable: store ethertype in flowtable context
netfilter: flowtable: rename ctx.tun.proto to ctx.tun.inner_proto
netfilter: flowtable: rename tun.l3_proto to tun.inner_proto
net: netfilter: add ether_type to net_device_path_ctx and use it
net: pass net_device_path_ctx to dev_fill_forward_path()
netfilter: add DEBUG_NET_WARN_ON_ONCE to skb_set_nfct()
====================
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jakub Kicinski <[email protected]>
Pull networking fixes from Paolo Abeni:
"Including fixes from netfilter.
There is a known WiFi/mt76 regression, waiting for a complete fix that
should land soonish.
Previous releases - regressions:
- tcp: fix icsk_ack.ato bitfield overflow
- af_unix: Unlink scc_entry in unix_del_edge()
- ipv4: fix use-after-free in fib_nhc_update_mtu()
- netfilter:
- ipset: fix refcount race between list:set GC and swap
- nf_tables_offload: suppress WARN_ON_ONCE for ENOMEM in abort
path
- sched: act_ct: fix sk_buff leak when the header checks reject a
packet
- sctp: clear new_transport when removing a peer
- dibs: correct freeing of dmb_clientid_arr
- ovpn: fix NULL dereference when killing missing key
- eth:
- veth: fix queue index used to wake the peer txq in veth_poll
- ngbe: fix NULL pointer dereference in non-MSI-X interrupt
enabling
- gve: fix zero-length skb frag with header-split
Previous releases - always broken:
- core: fix skb length accounting after generic XDP frag adjustment
- af_packet: don't send zero-byte data in tpacket_snd().
- eth:
- bnxt: avoid deadlock when canceling IRQ affinity notifier
- ipvlan: inherit needed_headroom and needed_tailroom from
phy_dev"
* tag 'net-7.2-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (55 commits)
l2tp: fix tunnel and session refcount leak on seq_file release
net/sched: cls_bpf: reject dev-bound programs bound to a different device
sctp: fix use-after-free of cached ASCONF chunk
net: ethernet: ti: am65-cpsw-nuss: Fix port_id extraction from SRC TAG
sctp: clear new_transport when removing a peer
net/dibs: Correct freeing of dmb_clientid_arr
net/sched: cls_u32: skip hash tables in u32_bind_class()
gve: fix NULL dereference due to missing ptp adjfine
gve: fix zero-length skb frag with header-split
net/sched: act_api: fix TOCTOU NULL deref on a->goto_chain
af_packet: Don't send zero-byte data in tpacket_snd().
tipc: read le->link under the node lock in tipc_node_link_down()
selftests: tls: cover splice after a failed decrypt
net/tls: Fail tls_sw_splice_read() after a failed async decrypt
net: ngbe: fix NULL pointer dereference in non-MSI-X interrupt enabling
net: tap: fix wrong transport_header when sending VLAN-tagged frame
net: packet: fix wrong transport_header when sending VLAN-tagged frame
vxlan: do not arm the ageing timer on a device that is down
ipv4: fix use-after-free in fib_nhc_update_mtu()
NTB: ntb_netdev: Preserve RX queue depth on allocation failure
...
Add duplication helpers in the cases where the ctl_table array elements
are modified after duplication. Helpers return a ctl_table as const
pointer allowing the const qualification of the static global ctl_table
array.
Signed-off-by: Joel Granados <[email protected]>
Link: https://patch.msgid.link/[email protected]
Reviewed-by: Simon Horman <[email protected]>
Signed-off-by: Paolo Abeni <[email protected]>
Pablo Neira Ayuso