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2026-04-10netfilter: require Ethernet MAC header before using eth_hdr()Zhengchuan Liang-12/+19
`ip6t_eui64`, `xt_mac`, the `bitmap:ip,mac`, `hash:ip,mac`, and `hash:mac` ipset types, and `nf_log_syslog` access `eth_hdr(skb)` after either assuming that the skb is associated with an Ethernet device or checking only that the `ETH_HLEN` bytes at `skb_mac_header(skb)` lie between `skb->head` and `skb->data`. Make these paths first verify that the skb is associated with an Ethernet device, that the MAC header was set, and that it spans at least a full Ethernet header before accessing `eth_hdr(skb)`. Suggested-by: Florian Westphal <fw@strlen.de> Tested-by: Ren Wei <enjou1224z@gmail.com> Signed-off-by: Zhengchuan Liang <zcliangcn@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: nft_fwd_netdev: check ttl/hl before forwardingFlorian Westphal-0/+10
Drop packets if their ttl/hl is too small for forwarding. Fixes: d32de98ea70f ("netfilter: nft_fwd_netdev: allow to forward packets via neighbour layer") Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: x_tables: Avoid a couple -Wflex-array-member-not-at-end warningsGustavo A. R. Silva-4/+8
-Wflex-array-member-not-at-end was introduced in GCC-14, and we are getting ready to enable it, globally. Use the TRAILING_OVERLAP() helper to fix the following warnings: 1 net/netfilter/x_tables.c:816:39: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] 1 net/netfilter/x_tables.c:811:39: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end] This helper creates a union between a flexible-array member (FAM) and a set of members that would otherwise follow it. This overlays the trailing members onto the FAM while preserving the original memory layout. Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: conntrack: remove UDP-Lite conntrack supportFernando Fernandez Mancera-160/+0
UDP-Lite (RFC 3828) socket support was recently retired from the core networking stack. As a follow-up of that, drop the connection tracker and NAT support for UDP-Lite in Netfilter. This patch removes CONFIG_NF_CT_PROTO_UDPLITE and scrubs UDP-Lite awareness from the conntrack core, NAT core, nft_ct, and ctnetlink. Please note that stateless packet inspection, matching, ipsets or logging support for IPPROTO_UDPLITE is preserved. As conntrack no longer extracts UDP-Lite ports or tracks its L4 state, when performing NAT the UDP-Lite checksum cannot be updated anymore. That is an expected and acceptable consequence of removing UDP-Lite conntrack module. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: xt_socket: enable defrag after all other checksFlorian Westphal-17/+6
Originally this did not matter because defrag was enabled once per netns and only disabled again on netns dismantle. When this got changed I should have adjusted checkentry to not leave defrag enabled on error. Fixes: de8c12110a13 ("netfilter: disable defrag once its no longer needed") Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: xt_HL: add pr_fmt and checkentry validationMarino Dzalto-0/+27
Add pr_fmt to prefix log messages with the module name for easier debugging in dmesg. Add checkentry functions for IPv4 (ttl_mt_check) and IPv6 (hl_mt6_check) to validate the match mode at rule registration time, rejecting invalid modes with -EINVAL. The evaluation function returns false in case the mode is unknown, so this is a cleanup, not a bug fix. Signed-off-by: Marino Dzalto <marino.dzalto@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: nfnetlink: prefer skb_mac_header helpersFlorian Westphal-22/+22
This adds implicit DEBUG_WARN_ON_ONCE for debug configurations. No other changes intended. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10netfilter: x_physdev: reject empty or not-nul terminated device namesFlorian Westphal-0/+22
Reject names that lack a \0 character and reject the empty string as well. iptables allows this but it fails to re-parse iptables-save output that contain such rules. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10ipvs: add conn_lfactor and svc_lfactor sysctl varsJulian Anastasov-0/+76
Allow the default load factor for the connection and service tables to be configured. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10ipvs: add ip_vs_status infoJulian Anastasov-0/+145
Add /proc/net/ip_vs_status to show current state of IPVS. The motivation for this new /proc interface is to provide the output for the users to help them decide when to tune the load factor for hash tables, which is possible with the new sysctl knobs coming in followup patch. The output also includes information for the kthreads used for stats. Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-10ipvs: show the current conn_tab size to usersJulian Anastasov-4/+22
As conn_tab is per-net, better to show the current hash table size to users instead of the ip_vs_conn_tab_size (max). Signed-off-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski-100/+84
Cross-merge networking fixes after downstream PR (net-7.0-rc8). Conflicts: net/ipv6/seg6_iptunnel.c c3812651b522f ("seg6: separate dst_cache for input and output paths in seg6 lwtunnel") 78723a62b969a ("seg6: add per-route tunnel source address") https://lore.kernel.org/adZhwtOYfo-0ImSa@sirena.org.uk net/ipv4/icmp.c fde29fd934932 ("ipv4: icmp: fix null-ptr-deref in icmp_build_probe()") d98adfbdd5c01 ("ipv4: drop ipv6_stub usage and use direct function calls") https://lore.kernel.org/adO3dccqnr6j-BL9@sirena.org.uk Adjacent changes: drivers/net/ethernet/stmicro/stmmac/chain_mode.c 51f4e090b9f8 ("net: stmmac: fix integer underflow in chain mode") 6b4286e05508 ("net: stmmac: rename STMMAC_GET_ENTRY() -> STMMAC_NEXT_ENTRY()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-08netfilter: nfnetlink_queue: make hash table per queueFlorian Westphal-90/+49
Sharing a global hash table among all queues is tempting, but it can cause crash: BUG: KASAN: slab-use-after-free in nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] [..] nfqnl_recv_verdict+0x11ac/0x15e0 [nfnetlink_queue] nfnetlink_rcv_msg+0x46a/0x930 kmem_cache_alloc_node_noprof+0x11e/0x450 struct nf_queue_entry is freed via kfree, but parallel cpu can still encounter such an nf_queue_entry when walking the list. Alternative fix is to free the nf_queue_entry via kfree_rcu() instead, but as we have to alloc/free for each skb this will cause more mem pressure. Cc: Scott Mitchell <scott.k.mitch1@gmail.com> Fixes: e19079adcd26 ("netfilter: nfnetlink_queue: optimize verdict lookup with hash table") Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nft_ct: fix use-after-free in timeout object destroyTuan Do-1/+1
nft_ct_timeout_obj_destroy() frees the timeout object with kfree() immediately after nf_ct_untimeout(), without waiting for an RCU grace period. Concurrent packet processing on other CPUs may still hold RCU-protected references to the timeout object obtained via rcu_dereference() in nf_ct_timeout_data(). Add an rcu_head to struct nf_ct_timeout and use kfree_rcu() to defer freeing until after an RCU grace period, matching the approach already used in nfnetlink_cttimeout.c. KASAN report: BUG: KASAN: slab-use-after-free in nf_conntrack_tcp_packet+0x1381/0x29d0 Read of size 4 at addr ffff8881035fe19c by task exploit/80 Call Trace: nf_conntrack_tcp_packet+0x1381/0x29d0 nf_conntrack_in+0x612/0x8b0 nf_hook_slow+0x70/0x100 __ip_local_out+0x1b2/0x210 tcp_sendmsg_locked+0x722/0x1580 __sys_sendto+0x2d8/0x320 Allocated by task 75: nft_ct_timeout_obj_init+0xf6/0x290 nft_obj_init+0x107/0x1b0 nf_tables_newobj+0x680/0x9c0 nfnetlink_rcv_batch+0xc29/0xe00 Freed by task 26: nft_obj_destroy+0x3f/0xa0 nf_tables_trans_destroy_work+0x51c/0x5c0 process_one_work+0x2c4/0x5a0 Fixes: 7e0b2b57f01d ("netfilter: nft_ct: add ct timeout support") Cc: stable@vger.kernel.org Signed-off-by: Tuan Do <tuan@calif.io> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: xt_multiport: validate range encoding in checkentryRen Wei-4/+30
ports_match_v1() treats any non-zero pflags entry as the start of a port range and unconditionally consumes the next ports[] element as the range end. The checkentry path currently validates protocol, flags and count, but it does not validate the range encoding itself. As a result, malformed rules can mark the last slot as a range start or place two range starts back to back, leaving ports_match_v1() to step past the last valid ports[] element while interpreting the rule. Reject malformed multiport v1 rules in checkentry by validating that each range start has a following element and that the following element is not itself marked as another range start. Fixes: a89ecb6a2ef7 ("[NETFILTER]: x_tables: unify IPv4/IPv6 multiport match") Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Co-developed-by: Yuan Tan <yuantan098@gmail.com> Signed-off-by: Yuan Tan <yuantan098@gmail.com> Suggested-by: Xin Liu <bird@lzu.edu.cn> Tested-by: Yuhang Zheng <z1652074432@gmail.com> Signed-off-by: Ren Wei <n05ec@lzu.edu.cn> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nfnetlink_log: initialize nfgenmsg in NLMSG_DONE terminatorXiang Mei-4/+4
When batching multiple NFLOG messages (inst->qlen > 1), __nfulnl_send() appends an NLMSG_DONE terminator with sizeof(struct nfgenmsg) payload via nlmsg_put(), but never initializes the nfgenmsg bytes. The nlmsg_put() helper only zeroes alignment padding after the payload, not the payload itself, so four bytes of stale kernel heap data are leaked to userspace in the NLMSG_DONE message body. Use nfnl_msg_put() to build the NLMSG_DONE terminator, which initializes the nfgenmsg payload via nfnl_fill_hdr(), consistent with how __build_packet_message() already constructs NFULNL_MSG_PACKET headers. Fixes: 29c5d4afba51 ("[NETFILTER]: nfnetlink_log: fix sending of multipart messages") Reported-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08ipvs: fix NULL deref in ip_vs_add_service error pathWeiming Shi-1/+0
When ip_vs_bind_scheduler() succeeds in ip_vs_add_service(), the local variable sched is set to NULL. If ip_vs_start_estimator() subsequently fails, the out_err cleanup calls ip_vs_unbind_scheduler(svc, sched) with sched == NULL. ip_vs_unbind_scheduler() passes the cur_sched NULL check (because svc->scheduler was set by the successful bind) but then dereferences the NULL sched parameter at sched->done_service, causing a kernel panic at offset 0x30 from NULL. Oops: general protection fault, [..] [#1] PREEMPT SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000030-0x0000000000000037] RIP: 0010:ip_vs_unbind_scheduler (net/netfilter/ipvs/ip_vs_sched.c:69) Call Trace: <TASK> ip_vs_add_service.isra.0 (net/netfilter/ipvs/ip_vs_ctl.c:1500) do_ip_vs_set_ctl (net/netfilter/ipvs/ip_vs_ctl.c:2809) nf_setsockopt (net/netfilter/nf_sockopt.c:102) [..] Fix by simply not clearing the local sched variable after a successful bind. ip_vs_unbind_scheduler() already detects whether a scheduler is installed via svc->scheduler, and keeping sched non-NULL ensures the error path passes the correct pointer to both ip_vs_unbind_scheduler() and ip_vs_scheduler_put(). While the bug is older, the problem popups in more recent kernels (6.2), when the new error path is taken after the ip_vs_start_estimator() call. Fixes: 705dd3444081 ("ipvs: use kthreads for stats estimation") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Acked-by: Simon Horman <horms@kernel.org> Acked-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nf_tables_offload: add nft_flow_action_entry_next() and use itPablo Neira Ayuso-2/+7
Add a new helper function to retrieve the next action entry in flow rule, check if the maximum number of actions is reached, bail out in such case. Replace existing opencoded iteration on the action array by this helper function. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nf_conntrack_h323: Correct indentation when H323_TRACE definedDavid Laight-19/+19
The trace lines are indented using PRINT("%*.s", xx, " "). Userspace will treat this as "%*.0s" and will output no characters when 'xx' is zero, the kernel treats it as "%*s" and will output a single ' ' - which is probably what is intended. Change all the formats to "%*s" removing the default precision. This gives a single space indent when level is zero. Signed-off-by: David Laight <david.laight.linux@gmail.com> Reviewed-by: Petr Mladek <pmladek@suse.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nft_meta: add double-tagged vlan and pppoe supportPablo Neira Ayuso-3/+55
Currently: add rule netdev x y ip saddr 1.1.1.1 does not work with neither double-tagged vlan nor pppoe packets. This is because the network and transport header offset are not pointing to the IP and transport protocol headers in the stack. This patch expands NFT_META_PROTOCOL and NFT_META_L4PROTO to parse double-tagged vlan and pppoe packets so matching network and transport header fields becomes possible with the existing userspace generated bytecode. Note that this parser only supports double-tagged vlan which is composed of vlan offload + vlan header in the skb payload area for simplicity. NFT_META_PROTOCOL is used by bridge and netdev family as an implicit dependency in the bytecode to match on network header fields. Similarly, there is also NFT_META_L4PROTO, which is also used as an implicit dependency when matching on the transport protocol header fields. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nft_set_pipapo_avx2: remove redundant loop in lookup_slowFlorian Westphal-23/+9
nft_pipapo_avx2_lookup_slow will never be used in reality, because the common sizes are handled by avx2 optimized versions. However, nft_pipapo_avx2_lookup_slow loops over the data just like the avx2 functions. However, _slow doesn't need to do that. As-is, first loop sets all the right result bits and the next iterations boil down to 'x = x & x'. Remove the loop. Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nft_set_pipapo: increment data in one stepFlorian Westphal-6/+1
Since commit e807b13cb3e3 ("nft_set_pipapo: Generalise group size for buckets") there is no longer a need to increment the data pointer in two steps. Switch to a single invocation of NFT_PIPAPO_GROUPS_PADDED_SIZE() helper, like the avx2 implementation. [ Stefano: Improve commit message ] Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nf_tables: add netlink policy based cap on registersFlorian Westphal-28/+28
Should have no effect in practice; all of these use the nft_parse_register_load/store apis which is mandatory anyway due to the need to further validate the register load/store, e.g. that the size argument doesn't result in out-of-bounds load/store. OTOH this is a simple method to reject obviously wrong input at earlier stage. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: add more netlink-based policy range checksFlorian Westphal-30/+43
These spots either already check the attribute range manually before use or the consuming functions tolerate unexpected values. Nevertheless, add more range checks via netlink policy so we gain more users and avoid possible re-use in other places that might not have the required manual checks. This also improves error reporting: netlink core can generate extack errors. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nf_conntrack_h323: remove unreliable debug code in decode_octstrFlorian Westphal-7/+0
The debug code (not enabled in any build) reads up to 6 octets of the inpt buffer, but does so without bound checks. Zap this. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: add deprecation warning for dccp supportFlorian Westphal-0/+6
Add a deprecation warning for the xt_dccp match and the nft exthdr code. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: nf_conntrack_sip: remove net variable shadowingFlorian Westphal-2/+1
net is already set, derived from nf_conn. I don't see how the device could be living in a different netns than the conntrack entry. Remove the extra variable and re-use existing one. Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-08netfilter: use function typedefs for __rcu NAT helper hook pointersSun Jian-34/+10
After commit 07919126ecfc ("netfilter: annotate NAT helper hook pointers with __rcu"), sparse can warn about type/address-space mismatches when RCU-dereferencing NAT helper hook function pointers. The hooks are __rcu-annotated and accessed via rcu_dereference(), but the combination of complex function pointer declarators and the WRITE_ONCE() machinery used by RCU_INIT_POINTER()/rcu_assign_pointer() can confuse sparse and trigger false positives. Introduce typedefs for the NAT helper function types, so __rcu applies to a simple "fn_t __rcu *" pointer form. Also replace local typeof(hook) variables with "fn_t *" to avoid propagating __rcu address space into temporaries. No functional change intended. Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202603022359.3dGE9fwI-lkp@intel.com/ Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de>
2026-04-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski-120/+191
Cross-merge networking fixes after downstream PR (net-7.0-rc7). Conflicts: net/vmw_vsock/af_vsock.c b18c83388874 ("vsock: initialize child_ns_mode_locked in vsock_net_init()") 0de607dc4fd8 ("vsock: add G2H fallback for CIDs not owned by H2G transport") Adjacent changes: drivers/net/ethernet/broadcom/bnxt/bnxt_ethtool.c ceee35e5674a ("bnxt_en: Refactor some basic ring setup and adjustment logic") 57cdfe0dc70b ("bnxt_en: Resize RSS contexts on channel count change") drivers/net/wireless/intel/iwlwifi/mld/mac80211.c 4d56037a02bd ("wifi: iwlwifi: mld: block EMLSR during TDLS connections") 687a95d204e7 ("wifi: iwlwifi: mld: correctly set wifi generation data") drivers/net/wireless/intel/iwlwifi/mld/scan.h b6045c899e37 ("wifi: iwlwifi: mld: Refactor scan command handling") ec66ec6a5a8f ("wifi: iwlwifi: mld: Fix MLO scan timing") drivers/net/wireless/intel/iwlwifi/mvm/fw.c 078df640ef05 ("wifi: iwlwifi: mld: add support for iwl_mcc_allowed_ap_type_cmd v 2") 323156c3541e ("wifi: iwlwifi: mvm: don't send a 6E related command when not supported") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-01netfilter: nf_tables: reject immediate NF_QUEUE verdictPablo Neira Ayuso-2/+5
nft_queue is always used from userspace nftables to deliver the NF_QUEUE verdict. Immediately emitting an NF_QUEUE verdict is never used by the userspace nft tools, so reject immediate NF_QUEUE verdicts. The arp family does not provide queue support, but such an immediate verdict is still reachable. Globally reject NF_QUEUE immediate verdicts to address this issue. Fixes: f342de4e2f33 ("netfilter: nf_tables: reject QUEUE/DROP verdict parameters") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: x_tables: restrict xt_check_match/xt_check_target extensions for ↵Pablo Neira Ayuso-0/+23
NFPROTO_ARP Weiming Shi says: xt_match and xt_target structs registered with NFPROTO_UNSPEC can be loaded by any protocol family through nft_compat. When such a match/target sets .hooks to restrict which hooks it may run on, the bitmask uses NF_INET_* constants. This is only correct for families whose hook layout matches NF_INET_*: IPv4, IPv6, INET, and bridge all share the same five hooks (PRE_ROUTING ... POST_ROUTING). ARP only has three hooks (IN=0, OUT=1, FORWARD=2) with different semantics. Because NF_ARP_OUT == 1 == NF_INET_LOCAL_IN, the .hooks validation silently passes for the wrong reasons, allowing matches to run on ARP chains where the hook assumptions (e.g. state->in being set on input hooks) do not hold. This leads to NULL pointer dereferences; xt_devgroup is one concrete example: Oops: general protection fault, probably for non-canonical address 0xdffffc0000000044: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000220-0x0000000000000227] RIP: 0010:devgroup_mt+0xff/0x350 Call Trace: <TASK> nft_match_eval (net/netfilter/nft_compat.c:407) nft_do_chain (net/netfilter/nf_tables_core.c:285) nft_do_chain_arp (net/netfilter/nft_chain_filter.c:61) nf_hook_slow (net/netfilter/core.c:623) arp_xmit (net/ipv4/arp.c:666) </TASK> Kernel panic - not syncing: Fatal exception in interrupt Fix it by restricting arptables to NFPROTO_ARP extensions only. Note that arptables-legacy only supports: - arpt_CLASSIFY - arpt_mangle - arpt_MARK that provide explicit NFPROTO_ARP match/target declarations. Fixes: 9291747f118d ("netfilter: xtables: add device group match") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: ipset: drop logically empty buckets in mtype_delYifan Wu-1/+1
mtype_del() counts empty slots below n->pos in k, but it only drops the bucket when both n->pos and k are zero. This misses buckets whose live entries have all been removed while n->pos still points past deleted slots. Treat a bucket as empty when all positions below n->pos are unused and release it directly instead of shrinking it further. Fixes: 8af1c6fbd923 ("netfilter: ipset: Fix forceadd evaluation path") Cc: stable@vger.kernel.org Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Xin Liu <dstsmallbird@foxmail.com> Signed-off-by: Yifan Wu <yifanwucs@gmail.com> Co-developed-by: Yuan Tan <yuantan098@gmail.com> Signed-off-by: Yuan Tan <yuantan098@gmail.com> Reviewed-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: ctnetlink: ignore explicit helper on new expectationsPablo Neira Ayuso-45/+9
Use the existing master conntrack helper, anything else is not really supported and it just makes validation more complicated, so just ignore what helper userspace suggests for this expectation. This was uncovered when validating CTA_EXPECT_CLASS via different helper provided by userspace than the existing master conntrack helper: BUG: KASAN: slab-out-of-bounds in nf_ct_expect_related_report+0x2479/0x27c0 Read of size 4 at addr ffff8880043fe408 by task poc/102 Call Trace: nf_ct_expect_related_report+0x2479/0x27c0 ctnetlink_create_expect+0x22b/0x3b0 ctnetlink_new_expect+0x4bd/0x5c0 nfnetlink_rcv_msg+0x67a/0x950 netlink_rcv_skb+0x120/0x350 Allowing to read kernel memory bytes off the expectation boundary. CTA_EXPECT_HELP_NAME is still used to offer the helper name to userspace via netlink dump. Fixes: bd0779370588 ("netfilter: nfnetlink_queue: allow to attach expectations to conntracks") Reported-by: Qi Tang <tpluszz77@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: ctnetlink: zero expect NAT fields when CTA_EXPECT_NAT absentQi Tang-0/+6
ctnetlink_alloc_expect() allocates expectations from a non-zeroing slab cache via nf_ct_expect_alloc(). When CTA_EXPECT_NAT is not present in the netlink message, saved_addr and saved_proto are never initialized. Stale data from a previous slab occupant can then be dumped to userspace by ctnetlink_exp_dump_expect(), which checks these fields to decide whether to emit CTA_EXPECT_NAT. The safe sibling nf_ct_expect_init(), used by the packet path, explicitly zeroes these fields. Zero saved_addr, saved_proto and dir in the else branch, guarded by IS_ENABLED(CONFIG_NF_NAT) since these fields only exist when NAT is enabled. Confirmed by priming the expect slab with NAT-bearing expectations, freeing them, creating a new expectation without CTA_EXPECT_NAT, and observing that the ctnetlink dump emits a spurious CTA_EXPECT_NAT containing stale data from the prior allocation. Fixes: 076a0ca02644 ("netfilter: ctnetlink: add NAT support for expectations") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Qi Tang <tpluszz77@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: nf_conntrack_helper: pass helper to expect cleanupQi Tang-1/+1
nf_conntrack_helper_unregister() calls nf_ct_expect_iterate_destroy() to remove expectations belonging to the helper being unregistered. However, it passes NULL instead of the helper pointer as the data argument, so expect_iter_me() never matches any expectation and all of them survive the cleanup. After unregister returns, nfnl_cthelper_del() frees the helper object immediately. Subsequent expectation dumps or packet-driven init_conntrack() calls then dereference the freed exp->helper, causing a use-after-free. Pass the actual helper pointer so expectations referencing it are properly destroyed before the helper object is freed. BUG: KASAN: slab-use-after-free in string+0x38f/0x430 Read of size 1 at addr ffff888003b14d20 by task poc/103 Call Trace: string+0x38f/0x430 vsnprintf+0x3cc/0x1170 seq_printf+0x17a/0x240 exp_seq_show+0x2e5/0x560 seq_read_iter+0x419/0x1280 proc_reg_read+0x1ac/0x270 vfs_read+0x179/0x930 ksys_read+0xef/0x1c0 Freed by task 103: The buggy address is located 32 bytes inside of freed 192-byte region [ffff888003b14d00, ffff888003b14dc0) Fixes: ac7b84839003 ("netfilter: expect: add and use nf_ct_expect_iterate helpers") Signed-off-by: Qi Tang <tpluszz77@gmail.com> Reviewed-by: Phil Sutter <phil@nwl.cc> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: ipset: use nla_strcmp for IPSET_ATTR_NAME attrFlorian Westphal-4/+4
IPSET_ATTR_NAME and IPSET_ATTR_NAMEREF are of NLA_STRING type, they cannot be treated like a c-string. They either have to be switched to NLA_NUL_STRING, or the compare operations need to use the nla functions. Fixes: f830837f0eed ("netfilter: ipset: list:set set type support") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: x_tables: ensure names are nul-terminatedFlorian Westphal-0/+11
Reject names that lack a \0 character before feeding them to functions that expect c-strings. Fixes tag is the most recent commit that needs this change. Fixes: c38c4597e4bf ("netfilter: implement xt_cgroup cgroup2 path match") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: nfnetlink_log: account for netlink header sizeFlorian Westphal-1/+1
This is a followup to an old bug fix: NLMSG_DONE needs to account for the netlink header size, not just the attribute size. This can result in a WARN splat + drop of the netlink message, but other than this there are no ill effects. Fixes: 9dfa1dfe4d5e ("netfilter: nf_log: account for size of NLMSG_DONE attribute") Reported-by: Yiming Qian <yimingqian591@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-04-01netfilter: flowtable: strictly check for maximum number of actionsPablo Neira Ayuso-66/+130
The maximum number of flowtable hardware offload actions in IPv6 is: * ethernet mangling (4 payload actions, 2 for each ethernet address) * SNAT (4 payload actions) * DNAT (4 payload actions) * Double VLAN (4 vlan actions, 2 for popping vlan, and 2 for pushing) for QinQ. * Redirect (1 action) Which makes 17, while the maximum is 16. But act_ct supports for tunnels actions too. Note that payload action operates at 32-bit word level, so mangling an IPv6 address takes 4 payload actions. Update flow_action_entry_next() calls to check for the maximum number of supported actions. While at it, rise the maximum number of actions per flow from 16 to 24 so this works fine with IPv6 setups. Fixes: c29f74e0df7a ("netfilter: nf_flow_table: hardware offload support") Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-29netfilter: remove nf_ipv6_ops and use direct function callsFernando Fernandez Mancera-27/+20
As IPv6 is built-in only, nf_ipv6_ops can be removed completely as it is not longer necessary. Convert all nf_ipv6_ops usage to direct function calls instead. In addition, remove the ipv6_netfilter_init/fini() functions as they are not necessary any longer. Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Link: https://patch.msgid.link/20260325120928.15848-12-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-29ipv6: convert CONFIG_IPV6 to built-in only and clean up KconfigsFernando Fernandez Mancera-8/+0
Maintaining a modular IPv6 stack offers image size savings for specific setups, this benefit is outweighed by the architectural burden it imposes on the subsystems on implementation and maintenance. Therefore, drop it. Change CONFIG_IPV6 from tristate to bool. Remove all Kconfig dependencies across the tree that explicitly checked for IPV6=m. In addition, remove MODULE_DESCRIPTION(), MODULE_ALIAS(), MODULE_AUTHOR() and MODULE_LICENSE(). This is also replacing module_init() by device_initcall(). It is not possible to use fs_initcall() as IPv4 does because that creates a race condition on IPv6 addrconf. Finally, modify the default configs from CONFIG_IPV6=m to CONFIG_IPV6=y except for m68k as according to the bloat-o-meter the image is increasing by 330KB~ and that isn't acceptable. Instead, disable IPv6 on this architecture by default. This is aligned with m68k RAM requirements and recommendations [1]. [1] http://www.linux-m68k.org/faq/ram.html Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Tested-by: Ricardo B. Marlière <rbm@suse.com> Acked-by: Krzysztof Kozlowski <krzk@kernel.org> # arm64 Link: https://patch.msgid.link/20260325120928.15848-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski-99/+196
Cross-merge networking fixes after downstream PR (net-7.0-rc6). No conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-26netfilter: ctnetlink: use netlink policy range checksDavid Carlier-18/+8
Replace manual range and mask validations with netlink policy annotations in ctnetlink code paths, so that the netlink core rejects invalid values early and can generate extack errors. - CTA_PROTOINFO_TCP_STATE: reject values > TCP_CONNTRACK_SYN_SENT2 at policy level, removing the manual >= TCP_CONNTRACK_MAX check. - CTA_PROTOINFO_TCP_WSCALE_ORIGINAL/REPLY: reject values > TCP_MAX_WSCALE (14). The normal TCP option parsing path already clamps to this value, but the ctnetlink path accepted 0-255, causing undefined behavior when used as a u32 shift count. - CTA_FILTER_ORIG_FLAGS/REPLY_FLAGS: use NLA_POLICY_MASK with CTA_FILTER_F_ALL, removing the manual mask checks. - CTA_EXPECT_FLAGS: use NLA_POLICY_MASK with NF_CT_EXPECT_MASK, adding a new mask define grouping all valid expect flags. Extracted from a broader nf-next patch by Florian Westphal, scoped to ctnetlink for the fixes tree. Fixes: c8e2078cfe41 ("[NETFILTER]: ctnetlink: add support for internal tcp connection tracking flags handling") Signed-off-by: David Carlier <devnexen@gmail.com> Co-developed-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nf_conntrack_sip: fix use of uninitialized rtp_addr in process_sdpWeiming Shi-4/+10
process_sdp() declares union nf_inet_addr rtp_addr on the stack and passes it to the nf_nat_sip sdp_session hook after walking the SDP media descriptions. However rtp_addr is only initialized inside the media loop when a recognized media type with a non-zero port is found. If the SDP body contains no m= lines, only inactive media sections (m=audio 0 ...) or only unrecognized media types, rtp_addr is never assigned. Despite that, the function still calls hooks->sdp_session() with &rtp_addr, causing nf_nat_sdp_session() to format the stale stack value as an IP address and rewrite the SDP session owner and connection lines with it. With CONFIG_INIT_STACK_ALL_ZERO (default on most distributions) this results in the session-level o= and c= addresses being rewritten to 0.0.0.0 for inactive SDP sessions. Without stack auto-init the rewritten address is whatever happened to be on the stack. Fix this by pre-initializing rtp_addr from the session-level connection address (caddr) when available, and tracking via a have_rtp_addr flag whether any valid address was established. Skip the sdp_session hook entirely when no valid address exists. Fixes: 4ab9e64e5e3c ("[NETFILTER]: nf_nat_sip: split up SDP mangling") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nf_conntrack_expect: skip expectations in other netns via procPablo Neira Ayuso-0/+4
Skip expectations that do not reside in this netns. Similar to e77e6ff502ea ("netfilter: conntrack: do not dump other netns's conntrack entries via proc"). Fixes: 9b03f38d0487 ("netfilter: netns nf_conntrack: per-netns expectations") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nf_conntrack_expect: store netns and zone in expectationPablo Neira Ayuso-3/+17
__nf_ct_expect_find() and nf_ct_expect_find_get() are called under rcu_read_lock() but they dereference the master conntrack via exp->master. Since the expectation does not hold a reference on the master conntrack, this could be dying conntrack or different recycled conntrack than the real master due to SLAB_TYPESAFE_RCU. Store the netns, the master_tuple and the zone in struct nf_conntrack_expect as a safety measure. This patch is required by the follow up fix not to dump expectations that do not belong to this netns. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: ctnetlink: ensure safe access to master conntrackPablo Neira Ayuso-10/+30
Holding reference on the expectation is not sufficient, the master conntrack object can just go away, making exp->master invalid. To access exp->master safely: - Grab the nf_conntrack_expect_lock, this gets serialized with clean_from_lists() which also holds this lock when the master conntrack goes away. - Hold reference on master conntrack via nf_conntrack_find_get(). Not so easy since the master tuple to look up for the master conntrack is not available in the existing problematic paths. This patch goes for extending the nf_conntrack_expect_lock section to address this issue for simplicity, in the cases that are described below this is just slightly extending the lock section. The add expectation command already holds a reference to the master conntrack from ctnetlink_create_expect(). However, the delete expectation command needs to grab the spinlock before looking up for the expectation. Expand the existing spinlock section to address this to cover the expectation lookup. Note that, the nf_ct_expect_iterate_net() calls already grabs the spinlock while iterating over the expectation table, which is correct. The get expectation command needs to grab the spinlock to ensure master conntrack does not go away. This also expands the existing spinlock section to cover the expectation lookup too. I needed to move the netlink skb allocation out of the spinlock to keep it GFP_KERNEL. For the expectation events, the IPEXP_DESTROY event is already delivered under the spinlock, just move the delivery of IPEXP_NEW under the spinlock too because the master conntrack event cache is reached through exp->master. While at it, add lockdep notations to help identify what codepaths need to grab the spinlock. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nf_conntrack_expect: use expect->helperPablo Neira Ayuso-21/+13
Use expect->helper in ctnetlink and /proc to dump the helper name. Using nfct_help() without holding a reference to the master conntrack is unsafe. Use exp->master->helper in ctnetlink path if userspace does not provide an explicit helper when creating an expectation to retain the existing behaviour. The ctnetlink expectation path holds the reference on the master conntrack and nf_conntrack_expect lock and the nfnetlink glue path refers to the master ct that is attached to the skb. Reported-by: Hyunwoo Kim <imv4bel@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nf_conntrack_expect: honor expectation helper fieldPablo Neira Ayuso-11/+28
The expectation helper field is mostly unused. As a result, the netfilter codebase relies on accessing the helper through exp->master. Always set on the expectation helper field so it can be used to reach the helper. nf_ct_expect_init() is called from packet path where the skb owns the ct object, therefore accessing exp->master for the newly created expectation is safe. This saves a lot of updates in all callsites to pass the ct object as parameter to nf_ct_expect_init(). This is a preparation patches for follow up fixes. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-03-26netfilter: nft_set_rbtree: revisit array resize logicPablo Neira Ayuso-17/+75
Chris Arges reports high memory consumption with thousands of containers, this patch revisits the array allocation logic. For anonymous sets, start by 16 slots (which takes 256 bytes on x86_64). Expand it by x2 until threshold of 512 slots is reached, over that threshold, expand it by x1.5. For non-anonymous set, start by 1024 slots in the array (which takes 16 Kbytes initially on x86_64). Expand it by x1.5. Use set->ndeact to subtract deactivated elements when calculating the number of the slots in the array, otherwise the array size array gets increased artifically. Add special case shrink logic to deal with flush set too. The shrink logic is skipped by anonymous sets. Use check_add_overflow() to calculate the new array size. Add a WARN_ON_ONCE check to make sure elements fit into the new array size. Reported-by: Chris Arges <carges@cloudflare.com> Fixes: 7e43e0a1141d ("netfilter: nft_set_rbtree: translate rbtree to array for binary search") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>