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2026-06-25rxrpc: Fix leak of released call in recvmsg(MSG_PEEK)David Howells1-2/+1
Fix rxrpc_recvmsg() to also drop the ref it holds on an already-released call if MSG_PEEK is in force (the function holds a ref on the call irrespective of whether MSG_PEEK is specified or not). Fixes: 962fb1f651c2 ("rxrpc: Fix recv-recv race of completed call") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-11-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix socket notification raceDavid Howells1-2/+0
There's a race between rxrpc_recvmsg() and rxrpc_notify_socket(), whereby the latter's attempt to avoid disabling interrupts and taking the socket's recvmsg_lock if the call is already queued may happen simultaneously with the former's discarding of a call that has nothing queued. Fix this by removing the shortcut. Note that this only affects userspace's use of AF_RXRPC; the AFS filesystem driver doesn't use the socket queue. Fixes: 248f219cb8bc ("rxrpc: Rewrite the data and ack handling code") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-10-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix potential infinite loop in rxrpc_recvmsg()David Howells1-1/+2
Fix the wait in rxrpc_recvmsg() also take check the oob queue. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-9-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix oob challenge leak in cleanup after notification failureDavid Howells3-6/+14
Fix rxrpc_notify_socket_oob() to return an indication of failure in the event that it failed to queue a packet and fix rxrpc_post_challenge() to clean up the connection ref in such an event. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-8-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix the reception of a reply packet before data transmissionDavid Howells1-3/+10
Fix rxrpc_receiving_reply() to handle the reception of an apparent reply DATA packet before rxrpc has had a chance to send any request DATA packets on a client call by checking to see if the call has been exposed yet by sending the first packet. Without this, rxrpc_rotate_tx_window() might oops. Also fix rxrpc_rotate_tx_window() to handle the Tx queue being empty by changing the do...while loop into a while loop, just in case a call is abnormally terminated by an early reply before the last request packet is transmitted. Fixes: b341a0263b1b ("rxrpc: Implement progressive transmission queue struct") Link: https://sashiko.dev/#/patchset/20260616155749.2125907-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Jeffrey Altman <jaltman@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-7-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix double unlock in rxrpc_recvmsg()David Howells1-1/+1
Fix a double unlock in rxrpc_recvmsg() when dealing with OOB messages. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260609140911.838677-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-4-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix leak of connection from OOB challengeDavid Howells1-0/+5
Fix leak of connection object from OOB challenge queue when response is provided by userspace. Fixes: 5800b1cf3fd8 ("rxrpc: Allow CHALLENGEs to the passed to the app for a RESPONSE") Link: https://sashiko.dev/#/patchset/20260609140911.838677-1-dhowells%40redhat.com Signed-off-by: David Howells <dhowells@redhat.com> cc: Marc Dionne <marc.dionne@auristor.com> cc: Simon Horman <horms@kernel.org> cc: linux-afs@lists.infradead.org cc: stable@kernel.org Link: https://patch.msgid.link/20260624163819.3017002-3-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25rxrpc: Fix ACKALL packet handlingWyatt Feng6-7/+30
rxrpc_input_ackall() accepts ACKALL packets without checking whether the call is in a state that can legitimately have outstanding transmit buffers. A forged ACKALL can therefore reach a new service call in RXRPC_CALL_SERVER_RECV_REQUEST before any reply packets have been queued. In that state call->tx_top is zero and call->tx_queue is NULL, so rxrpc_rotate_tx_window() dereferences a NULL txqueue and triggers a null-pointer dereference. Fix the handling of ACKALL packets by the following means: (1) Add two new call states: RXRPC_CALL_CLIENT_PRE_SEND which indicates that the client call is connected, but nothing has been transmitted as yet; and RXRPC_CALL_CLIENT_AWAIT_ACK, which indicates that everything has been transmitted at least once, but we're now waiting for the stuff remaining in the Tx buffer to be ACK'd (retransmissions may still happen). The RXRPC_CALL_CLIENT_PRE_SEND state is set when the call is assigned a channel and transitions to RXRPC_CALL_CLIENT_SEND_REQUEST when the first packet is transmitted. RXRPC_CALL_CLIENT_AWAIT_REPLY is then narrowed in scope to indicate that all Tx packets have been ACK'd and we're now waiting for the reply to be received. (2) As per Wyatt Feng's original patch[1], the ACKALL handler then checks that the call state is one in which there might be stuff in the Tx buffer to ACK, but now this includes AWAIT_ACK rather than AWAIT_REPLY. ACKALL packets are ignored if received in the wrong state. Note that unlike Wyatt Feng's patch, it's no longer necessary to check to see if the Tx buffer exists as this the state set now covers this. (3) Make the ACKALL handler use call->tx_transmitted rather than call->tx_top as the former is explicitly the highest packet seq number transmitted, whereas the latter has a looser definition. Thanks to Jeffrey Altman for a description of the history of the ACKALL packet[1]. Fixes: b341a0263b1b ("rxrpc: Implement progressive transmission queue struct") Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Signed-off-by: Wyatt Feng <bronzed_45_vested@icloud.com> Co-developed-by: David Howells <dhowells@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Ren Wei <n05ec@lzu.edu.cn> cc: Marc Dionne <marc.dionne@auristor.com> cc: linux-afs@lists.infradead.org Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20260616155749.2125907-2-dhowells@redhat.com/ [1] Link: https://lore.kernel.org/r/c0fd4fec-1576-4070-b31e-a37d5506f5ed@auristor.com/ [2] Reviewed-by: Jeffrey Altman <jaltman@auristor.com> Link: https://patch.msgid.link/20260624163819.3017002-2-dhowells@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25tipc: avoid busy looping in tipc_exit_net()Eric Dumazet2-3/+5
Blamed commit introduced a busy-wait loop in tipc_exit_net() to wait for pending UDP bearer cleanup works to complete: while (atomic_read(&tn->wq_count)) cond_resched(); This loop can busy-wait for a long time if cond_resched() is a NOP. This typically happens if the netns exit is executed by a high priority task, or under kernels configured without preemption (CONFIG_PREEMPT_NONE). In such cases, it wastes CPU cycles and can lead to soft lockups. Fix this by replacing the busy loop with wait_var_event(), allowing the thread to sleep properly until the work queue count reaches zero. Accordingly, update cleanup_bearer() to use atomic_dec_and_test() and wake_up_var() to wake up the waiter when the count drops to zero. This uses the global wait queue hash table, avoiding the need to bloat struct tipc_net with a wait_queue_head_t. The atomic_dec_and_test() provides the necessary memory barrier to ensure the wakeup is not missed. Fixes: 04c26faa51d1 ("tipc: wait and exit until all work queues are done") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jon Maloy <jmaloy@redhat.com> Cc: tipc-discussion@lists.sourceforge.net Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20260623173030.2925059-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25tipc: fix UAF in cleanup_bearer() due to premature dst_cache_destroy()Eric Dumazet1-4/+11
TIPC UDP media bearer teardown calls dst_cache_destroy() on its replicast caches before calling synchronize_net() to wait for concurrent RCU readers (transmitters) to finish: static void cleanup_bearer(struct work_struct *work) { ... list_for_each_entry_safe(rcast, tmp, &ub->rcast.list, list) { dst_cache_destroy(&rcast->dst_cache); list_del_rcu(&rcast->list); kfree_rcu(rcast, rcu); } ... dst_cache_destroy(&ub->rcast.dst_cache); udp_tunnel_sock_release(ub->sk); synchronize_net(); ... } This is highly buggy because dst_cache_destroy() immediately frees the per-CPU cache memory (free_percpu()) and releases the cached dst entries without any synchronization. If a concurrent transmitter (e.g., tipc_udp_xmit()) is running on another CPU under RCU protection, it can call dst_cache_get() concurrently, leading to: 1. Use-After-Free on the per-CPU cache pointer itself (crash). 2. "rcuref - imbalanced put()" warning if it attempts to release a dst that was concurrently released by dst_cache_destroy(). Furthermore, calling kfree(ub) immediately after synchronize_net() without closing the socket first (or waiting after closing it) leaves a window where a concurrent receiver (tipc_udp_recv()) could start after synchronize_net(), access ub, and suffer a UAF when kfree(ub) runs. To fix this, we must defer dst_cache_destroy() and kfree(ub) until after we have ensured that no more readers can see the bearer/socket and all existing readers have finished: 1. Defer rcast entry destruction (both dst_cache_destroy() and kfree()) to an RCU callback using call_rcu_hurry(). Using call_rcu_hurry() ensures the dst entries are released quickly. 2. Release the bearer socket using udp_tunnel_sock_release() (stops new receive readers). 3. Call synchronize_net() to wait for all outstanding RCU readers (both transmit and receive) to finish. 4. Now that it is safe, call dst_cache_destroy() on the main bearer cache, and free ub. Note: 3) and 4) can be changed later in net-next to also use call_rcu_hurry() and get rid of the synchronize_net() latency. Fixes: e9c1a793210f ("tipc: add dst_cache support for udp media") Reported-by: syzbot+e14bc5d4942756023b77@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6a396a66.52ae72c2.136ac7.0003.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Jon Maloy <jmaloy@redhat.com> Cc: tipc-discussion@lists.sourceforge.net Reviewed-by: Xin Long <lucien.xin@gmail.com> Link: https://patch.msgid.link/20260623173030.2925059-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25openvswitch: conntrack: annotate ct limit hlist traversalRunyu Xiao1-1/+2
ct_limit_set() is documented as being called with ovs_mutex held. It walks the ct limit hlist with hlist_for_each_entry_rcu(), but the iterator does not currently pass the OVS lockdep condition used elsewhere for RCU-protected OVS objects. Pass lockdep_ovsl_is_held() to the iterator. This matches the function's existing caller contract and lets CONFIG_PROVE_RCU_LIST distinguish the ovs_mutex-protected update path from the RCU read-side ct_limit_get() path. This was found by our static analysis tool and then manually reviewed against the current tree. In the reviewed CONFIG_PROVE_RCU_LIST triage run, the writer-side ct limit update produced the expected "RCU-list traversed in non-reader section!!" warning while ovs_mutex was held, with the stack matching ct_limit_set() and ovs_ct_limit_set_zone_limit(). The change is limited to documenting the existing protection contract. This is a lockdep annotation cleanup. It does not change the conntrack limit list update or release behavior. Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Reviewed-by: Eelco Chaudron <echaudro@redhat.com> Link: https://patch.msgid.link/20260624150149.3510541-1-runyu.xiao@seu.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-25net: udp_tunnel: prevent double queueing in udp_tunnel_nic_device_syncEric Dumazet1-1/+1
Yue Sun reported a use-after-free and debugobjects warning in udp_tunnel_nic_device_sync_work() during concurrent device operations. The workqueue core clears the internal pending bit before invoking the worker. At that point, a concurrent thread can queue the work again. When the already running worker eventually clears the work_pending flag to 0, it mistakenly clears the flag for the newly queued instance. udp_tunnel_nic_unregister() then observes work_pending as 0 and frees the structure while the second work item is still active in the queue, leading to UAF. Fix this by returning early in udp_tunnel_nic_device_sync() if work_pending is already set, preventing redundant work queueing. Fixes: cc4e3835eff4 ("udp_tunnel: add central NIC RX port offload infrastructure") Reported-by: Yue Sun <samsun1006219@gmail.com> Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260625065938.654652-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-24Merge tag 'nf-26-06-23' of ↵Jakub Kicinski13-48/+95
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net: 1) Add a workaround to avoid a possible crash if nf_nat and nft_chain_nat are compiled built-in and nf_nat fails to register, allowing nft_chain_nat to access the incorrect pernetns area. This is crash specific of all built-in compilation. From Matias Krause. 2) Revisit conncount GC optimization for confirmed conntracks, skip GC round if IPS_ASSURED is set on. This is addressing an issue for corner case use case scenario involving locally generated traffic. No crash, just a functionality fix. From Fernando F. Mancera. 3) Validate iph->ihl in flowtable IPIP tunnel support, from Lorenzo Bianconi. This a sanity check to bounces back malformed IPIP packets to classic forwarding path. 4) Kdoc fixes for x_tables.h, from Randy Dunlap. 5) Use info->options so nft_synproxy_tcp_options() stays on the same local snapshot, otherwise eval path can observe inconsistent mix of mss and timestamps. From Runyu Xiao. 6) Add conntrack_sctp_collision.sh to cover for SCTP INIT collisions. From Yi Chen. 7) Do not allow NFPROTO_UNSPEC targets if family is NFPROTO_BRIDGE in nft_compat. This allows to use non-sense targets such as xt_nat leading to crash. From Florian Westphal. 8) Add a selftest queueing from bridge family. From Florian Westphal. 9) Do not allow to reset a conntrack helper via ctnetlink. This feature antedates the creation of the conntrack-tools, and it is not used I don't have a usecase for it, I prefer to remove than fixing it. 10) Add deprecation warning for IPv4 only conntrack helpers for PPTP and IRC. From Florian Westphal. 11) Store the master tuple in the expectation object and use it, otherwise SLAB_TYPESAFE_RCU rules allow to display incorrect master tuple information through ctnetlink. 12) Run expectation eviction when inserting an expectation with no helper, this is a fix for the nft_ct custom expectation support. 13) Fix nft_ct custom expectation timeouts, userspace provides a timeout in milliseconds but kernel assumes this comes in seconds. From Florian Westphal. 14) Cap maximum number of expectations per class to 255 expectations per master conntrack at helper registration. This is a fix to restrict the maximum number of expectations per master conntrack which can be a issue for the new lazy GC expectation approach. * tag 'nf-26-06-23' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nf_conntrack_helper: cap maximum number of expectation at helper registration netfilter: nft_ct: expectation timeouts are passed in milliseconds netfilter: nf_conntrack_expect: run expectation eviction with no helper netfilter: nf_conntrack_expect: store master_tuple in expectation netfilter: conntrack: add deprecation warnings for irc and pptp trackers netfilter: ctnetlink: do not allow to reset helper on existing conntrack selftests: nft_queue.sh: add a bridge queue test netfilter: nft_compat: ebtables emulation must reject non-bridge targets selftests: netfilter: conntrack_sctp_collision.sh: Introduce SCTP INIT collision test netfilter: nft_synproxy: stop bypassing the priv->info snapshot netfilter: x_tables.h: fix all kernel-doc warnings netfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto() netfilter: nf_conncount: prevent connlimit drops for early confirmed ct netfilter: nf_nat: avoid invalid nat_net pointer use on failed nf_nat_init() ==================== Link: https://patch.msgid.link/20260623221548.701545-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-24net/tcp-ao: fix use-after-free of key in del_async pathHanQuan1-0/+4
In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted. Fixes: d6732b95b6fb ("net/tcp: Allow asynchronous delete for TCP-AO keys (MKTs)") Signed-off-by: HanQuan <eilaimemedsnaimel@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260623015208.1191687-1-eilaimemedsnaimel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix missing notification for ignore_routes_with_linkdownFernando Fernandez Mancera1-6/+12
When changing the ignore_routes_with_linkdown sysctl for a specific interface, the RTM_NEWNETCONF netlink notification was not being emitted to userspace. Fix this by emitting the notification when needed. In addition, fix bogus return value for successful "all" and specific interface write operation leading to a wrong reset of the position pointer. Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-7-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix state corruption during proxy_ndp sysctl restartFernando Fernandez Mancera1-7/+7
When handling proxy_ndp, if rtnl_net_trylock() fails, the operation is retried but as the value was already modified by the initial proc_dointvec() call, the restarted syscall will read the newly modified value as the 'old' state. Fix this by taking the RTNL lock before parsing the input value if the operation is a write. Fixes: c92d5491a6d9 ("netconf: add support for IPv6 proxy_ndp") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-6-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix error handling in disable_policy sysctlFernando Fernandez Mancera1-0/+2
When writing to the disable_policy sysctl, if proc_dointvec() fails to parse the input, it returns a negative error code. The current implementation is resetting the position argument even if an error occurred during proc_dointvec() and not only during sysctl restart. Fix this by checking the return value of proc_dointvec() and returning early on failure. Fixes: df789fe75206 ("ipv6: Provide ipv6 version of "disable_policy" sysctl") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-5-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix error handling in forwarding sysctlFernando Fernandez Mancera1-1/+3
When writing to the forwarding sysctl, if proc_dointvec() fails to parse the input, it returns a negative error code. The current implementation is overwriting that error for write operations. This results in a silent failure, it returns a successful write although the configuration was not modified at all. When modifying the "all" variant it can also modify the configuration of existing interfaces to the wrong value. Fix this by checking the return value of proc_dointvec() and returning early on failure. In addition, adjust return code of addrconf_fixup_forwarding() for successful operation. Fixes: b325fddb7f86 ("ipv6: Fix sysctl unregistration deadlock") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-4-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix error handling in ignore_routes_with_linkdown sysctlFernando Fernandez Mancera1-0/+2
When writing to the ignore_routes_with_linkdown sysctl, if proc_dointvec() fails to parse the input, it returns a negative error code. The current implementation is overwriting that error for write operations. This results in a silent failure, it returns a successful write although the configuration was not modified at all. When modifying the "all" variant it can also modify the configuration of existing interfaces to the wrong value. Fix this by checking the return value of proc_dointvec() and returning early on failure. Fixes: 35103d11173b ("net: ipv6 sysctl option to ignore routes when nexthop link is down") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-3-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23ipv6: fix error handling in disable_ipv6 sysctlFernando Fernandez Mancera1-0/+2
When writing to the disable_ipv6 sysctl, if proc_dointvec() fails to parse the input, it returns a negative error code. The current implementation is overwriting that error for write operations. This results in a silent failure, it returns a successful write although the configuration was not modified at all. When modifying the "all" variant it can also modify the configuration of existing interfaces to the wrong value. Fix this by checking the return value of proc_dointvec() and returning early on failure. Fixes: 56d417b12e57 ("IPv6: Add 'autoconf' and 'disable_ipv6' module parameters") Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260622130857.5115-2-fmancera@suse.de Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23sctp: fix err_chunk memory leaks in INIT handlingXin Long1-0/+5
When sctp_verify_init() encounters unrecognized parameters, it allocates an err_chunk to report them. However, this chunk is leaked in several code paths: 1. In sctp_sf_do_5_1B_init(), if security_sctp_assoc_request() fails after sctp_verify_init() has populated err_chunk, the function returns immediately without freeing it. 2. In sctp_sf_do_unexpected_init(), the same leak occurs on the security_sctp_assoc_request() failure path. 3. In sctp_sf_do_unexpected_init(), on the success path after copying unrecognized parameters to the INIT-ACK, the function returns without freeing err_chunk, unlike sctp_sf_do_5_1B_init() which properly frees it. Fix all three leaks by adding sctp_chunk_free(err_chunk) calls before returning in the error paths and on the success path in sctp_sf_do_unexpected_init(). Fixes: c081d53f97a1 ("security: pass asoc to sctp_assoc_request and sctp_sk_clone") Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: Sashiko <sashiko-bot@kernel.org> Signed-off-by: Xin Long <lucien.xin@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/0656704f1b0158287c98aec09ba36c83e4a537ab.1781970534.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23net/sched: cls_api: Handle TC_ACT_CONSUMED in tcf_qevent_handleJamal Hadi Salim1-0/+3
tcf_classify() can return TC_ACT_CONSUMED while the skb is held by the defragmentation engine (e.g. act_ct on out-of-order fragments). When that happens the skb is no longer owned by the caller and must not be touched again. tcf_qevent_handle() did not handle TC_ACT_CONSUMED: it fell through the switch and returned the skb to the caller as if classification had passed. The only qdisc that wires up qevents today is RED, via three call sites (qe_mark on RED_PROB_MARK/HARD_MARK, qe_early_drop on congestion_drop) red_enqueue() was continuing to operate on an skb it no longer owns in this case -- enqueueing it, dropping it, or updating statistics. Resulting in a UAF. tc qdisc add dev eth0 root handle 1: red ... qevent early_drop block 10 tc filter add block 10 ... action ct (with ct defrag enabled and traffic that produces out-of-order fragments, e.g. a fragmented UDP stream) Handle TC_ACT_CONSUMED in tcf_qevent_handle() the same way the ingress and egress fast paths do: treat it as stolen and return NULL without touching the skb. Unlike the TC_ACT_STOLEN case, the skb must not be dropped/freed here, as it is no longer owned by us. Fixes: 3f14b377d01d ("net/sched: act_ct: fix skb leak and crash on ooo frags") Reported-by: Zero Day Initiative <zdi-disclosures@trendmicro.com> Tested-by: Victor Nogueira <victor@mojatatu.com> Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20260620130749.226642-1-jhs@mojatatu.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23net: lwtunnel: Drop skb metadata before LWT encapsulationJakub Sitnicki1-0/+6
skb metadata is meant for passing information between XDP and TC. It lives in the skb headroom, immediately before skb->data. LWT programs cannot access the __sk_buff->data_meta pseudo-pointer to metadata. However, LWT encapsulation prepends outer headers, moving skb->data back over the headroom where the metadata sits. On an RX-originated (forwarded) packet that still carries XDP metadata this goes wrong in two different ways, depending on the encap type: 1. Non-BPF LWT encaps (mpls, seg6, ioam6 ...) call skb_push()/skb_pull() and silently overwrite the metadata that sits in the headroom. 2) BPF LWT xmit calls bpf_skb_change_head(), which uses skb_data_move(). That helper expects metadata immediately before skb->data. But since the IP output path runs LWT xmit before neighbour output has built the outgoing L2 header, for forwarded packets skb->data points at the L3 header while skb_mac_header() still points at the old L2 header. skb_data_move() sees metadata ending at skb_mac_header(), not before skb->data, warns and clears metadata: WARNING: CPU: 21 PID: 454557 at include/linux/skbuff.h:4609 skb_data_move+0x47/0x90 CPU: 21 UID: 0 PID: 454557 Comm: napi/iconduit-g Tainted: G O 6.18.21 #1 RIP: 0010:skb_data_move+0x47/0x90 Call Trace: <IRQ> bpf_skb_change_head+0xe6/0x1a0 bpf_prog_...+0x213/0x2e3 run_lwt_bpf.isra.0+0x1d3/0x360 bpf_xmit+0x46/0xe0 lwtunnel_xmit+0xa1/0xf0 ip_finish_output2+0x1e7/0x5e0 ip_output+0x63/0x100 __netif_receive_skb_one_core+0x85/0xa0 process_backlog+0x9c/0x150 __napi_poll+0x2b/0x190 net_rx_action+0x40b/0x7f0 handle_softirqs+0xd2/0x270 do_softirq+0x3f/0x60 </IRQ> That is what happens, as for how to fix it - a received packet that carries metadata can reach an encap through any of the three LWT redirect modes: LWTUNNEL_STATE_INPUT_REDIRECT ip6_rcv_finish dst_input lwtunnel_input LWTUNNEL_STATE_OUTPUT_REDIRECT ip6_rcv_finish dst_input ip6_forward ip6_forward_finish dst_output lwtunnel_output LWTUNNEL_STATE_XMIT_REDIRECT ip6_rcv_finish dst_input ip6_forward ip6_forward_finish dst_output ip6_output ip6_finish_output ip6_finish_output2 lwtunnel_xmit Every encap funnels through the three LWT dispatch helpers, so drop the metadata there, right before handing the skb to the encap op. This single chokepoint covers all encap types and all three redirect modes: - lwtunnel_input(): seg6, rpl, ila, seg6_local - lwtunnel_output(): ioam6 - lwtunnel_xmit(): mpls, LWT BPF xmit Alternatively, we could clear the metadata right after TC ingress hook. That would require a compromise, however. Metadata would become inaccessible from TC egress (in setups where it actually reaches the hook it tact, that is without any L2 tunnels on path). Fixes: 8989d328dfe7 ("net: Helper to move packet data and metadata after skb_push/pull") Signed-off-by: Jakub Sitnicki <jakub@cloudflare.com> Link: https://patch.msgid.link/20260619-bpf-lwt-drop-skb-metadata-v3-1-71d6a33ab76b@cloudflare.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23Merge tag 'nfs-for-7.2-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds7-93/+349
Pull NFS client updates from Anna Schumaker: "New features: - XPRTRDMA: Decouple req recycling from RPC completion - NFS: Expose FMODE_NOWAIT for read-only files Bugfixes: - SUNRPC: - Fix sunrpc sysfs error handling - Fix uninitialized xprt_create_args structure - XPRTRDMA: - Harden connect and reply handling - NFS: - Fix EOF updates after fallocate/zero-range - Keep PG_UPTODATE clear after read errors in page groups - Use nfsi->rwsem to protect traversal of the file lock list - Prevent resource leak in nfs_alloc_server() - NFSv4: - Clear exception state on successful mkdir retry - Don't skip revalidate when holding a dir delegation and attrs are stale - pNFS: - Fix use-after-free in pnfs_update_layout() - Defer return_range callbacks until after inode unlock - Fix LAYOUTCOMMIT retry loop on OLD_STATEID - Reject zero-length r_addr in nfs4_decode_mp_ds_addr - NFS/flexfiles: - Reject zero-length filehandle version arrays - Fix checking if a layout is striped - Fixes for honoring FF_FLAGS_NO_IO_THRU_MDS Other cleanups and improvements: - Remove the fileid field from struct nfs_inode - Move long-delayed xprtrdma work onto the system_dfl_long_wq - Convert xprtrdma send buffer free list to an llist - Show "<redacted>" for cert_serial and privkey_serial mount options" * tag 'nfs-for-7.2-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (42 commits) NFS: Use common error handling code in nfs_alloc_server() NFS: Prevent resource leak in nfs_alloc_server() NFSv4/pNFS: reject zero-length r_addr in nfs4_decode_mp_ds_addr nfs: don't skip revalidate on directory delegation when attrs flagged stale xprtrdma: Return sendctx slot after Send preparation failure xprtrdma: Repost Receive buffers for malformed replies xprtrdma: Sanitize the reply credit grant after parsing xprtrdma: Fix bcall rep leak and unbounded peek xprtrdma: Resize reply buffers before reposting receives xprtrdma: Check frwr_wp_create() during connect xprtrdma: Initialize re_id before removal registration xprtrdma: Fix ep kref imbalance on ADDR_CHANGE xprtrdma: Convert send buffer free list to llist NFS: correct CONFIG_NFS_V4 macro name in #endif comment nfs: use nfsi->rwsem to protect traversal of the file lock list NFSv4.1/pNFS: fix LAYOUTCOMMIT retry loop on OLD_STATEID nfs: expose FMODE_NOWAIT for read-only files nfs: add nowait version of nfs_start_io_direct NFSv4/flexfiles: honor FF_FLAGS_NO_IO_THRU_MDS in pg_get_mirror_count_write NFSv4/flexfiles: honor FF_FLAGS_NO_IO_THRU_MDS on fatal DS connect errors ...
2026-06-23Merge tag 'ipsec-2026-06-22' of ↵Jakub Kicinski8-74/+64
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec Steffen Klassert says: ==================== pull request (net): ipsec 2026-06-22 1) xfrm: use compat translator only for u64 alignment mismatch Gate the XFRM_USER_COMPAT translator on COMPAT_FOR_U64_ALIGNMENT so 32-bit compat tasks on arches whose 32-bit ABI already matches the native 64-bit layout are no longer rejected with -EOPNOTSUPP. From Sanman Pradhan. 2) net: af_key: initialize alg_key_len for IPComp states Initialize the alg_key_len to 0 in the IPComp branch of pfkey_msg2xfrm_state() so an uninitialized value cannot drive xfrm_alg_len() into a slab-out-of-bounds kmemdup during XFRM_MSG_MIGRATE. From Zijing Yin. 3) xfrm: Fix dev use-after-free in xfrm async resumption Stash the original skb->dev and extend the RCU critical section across xfrm_rcv_cb() and transport_finish() to prevent a tunnel-device UAF and original-device refcount leak when a callback replaces skb->dev. From Dong Chenchen. 4) xfrm: Fix xfrm state cache insertion race Move the state-validity check inside xfrm_state_lock in the input state cache insertion path so a state cannot be killed between the check and the insert. From Herbert Xu. 5) xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] Add READ_ONCE()/WRITE_ONCE() annotations on xfrm_policy_count and xfrm_policy_default to silence the KCSAN data race reported on net->xfrm.policy_count. From Eric Dumazet. 6) espintcp: use sk_msg_free_partial to fix partial send Replace the manual skmsg accounting in espintcp with sk_msg_free_partial() so the skmsg stays consistent on every iteration and the partial-send accounting bugs go away. From Sabrina Dubroca. 7) xfrm: validate selector family and prefixlen during match Reject mismatched address families in xfrm_selector_match() and bound prefixlen in addr4_match()/addr_match() to prevent the shift-out-of-bounds syzbot reported when an AF_UNSPEC selector with a large prefixlen is matched against an IPv4 flow. From Eric Dumazet. * tag 'ipsec-2026-06-22' of git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec: xfrm: validate selector family and prefixlen during match espintcp: use sk_msg_free_partial to fix partial send xfrm: annotate data-races around xfrm_policy_count[] and xfrm_policy_default[] xfrm: Fix xfrm state cache insertion race xfrm: Fix dev use-after-free in xfrm async resumption net: af_key: initialize alg_key_len for IPComp states xfrm: use compat translator only for u64 alignment mismatch ==================== Link: https://patch.msgid.link/20260622075726.29685-1-steffen.klassert@secunet.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23net: do not acquire dev->tx_global_lock in netdev_watchdog_up()Eric Dumazet1-5/+2
Marek Szyprowski reported a deadlock during system resume when virtio_net driver is used. The deadlock occurs because netif_device_attach() is called while holding dev->tx_global_lock (via netif_tx_lock_bh() in virtnet_restore_up()). netif_device_attach() calls __netdev_watchdog_up(), which now also tries to acquire dev->tx_global_lock to synchronize with dev_watchdog(). This recursive lock acquisition results in a deadlock. Fix this by removing the tx_global_lock acquisition from netdev_watchdog_up(). The critical state (watchdog_timer and watchdog_ref_held) is already protected by dev->watchdog_lock, which was introduced in the blamed commit. Fixes: 8eed5519e496 ("net: watchdog: fix refcount tracking races") Reported-by: Marek Szyprowski <m.szyprowski@samsung.com> Closes: https://lore.kernel.org/netdev/a443376e-5187-4268-93b3-58047ef113a8@samsung.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260622110108.69541-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23net, bpf: check master for NULL in xdp_master_redirect()Xiang Mei1-1/+1
xdp_master_redirect() dereferences the result of netdev_master_upper_dev_get_rcu() without a NULL check, but that helper returns NULL when the receiving device has no upper-master adjacency. The reach guard only checks netif_is_bond_slave(). On bond slave release bond_upper_dev_unlink() drops the upper-master adjacency before clearing IFF_SLAVE, so an XDP_TX reaching xdp_master_redirect() in that window still passes netif_is_bond_slave() while master is already NULL, and faults on master->flags at offset 0xb0: BUG: kernel NULL pointer dereference, address: 00000000000000b0 RIP: 0010:xdp_master_redirect (net/core/filter.c:4432) Call Trace: xdp_master_redirect (net/core/filter.c:4432) bpf_prog_run_generic_xdp (include/net/xdp.h:700) do_xdp_generic (net/core/dev.c:5608) __netif_receive_skb_one_core (net/core/dev.c:6204) process_backlog (net/core/dev.c:6319) __napi_poll (net/core/dev.c:7729) net_rx_action (net/core/dev.c:7792) handle_softirqs (kernel/softirq.c:622) __dev_queue_xmit (include/linux/bottom_half.h:33) packet_sendmsg (net/packet/af_packet.c:3082) __sys_sendto (net/socket.c:2252) Kernel panic - not syncing: Fatal exception in interrupt The missing check dates back to the original code; commit 1921f91298d1 ("net, bpf: fix null-ptr-deref in xdp_master_redirect() for down master") later added the master->flags read where the fault now lands but kept the unconditional deref. Check master for NULL before use; a NULL master is treated the same as one that is not up. Fixes: 879af96ffd72 ("net, core: Add support for XDP redirection to slave device") Reported-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20260620201531.180123-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-23netfilter: nf_conntrack_helper: cap maximum number of expectation at helper ↵Pablo Neira Ayuso2-4/+8
registration On helper registration, the maximum number of expectations cannot go over NF_CT_EXPECT_MAX_CNT (255), but zero can be specified then nf_conntrack_expect_max applies. Turn zero into NF_CT_EXPECT_MAX_CNT otherwise, expectation LRU eviction on insertion is disabled. Moreover, expand this sanity check all expectation classes. This max_expecy policy is only tunable since userspace helpers are available, set Fixes: tag to the commit that adds such infrastructure. Remove the check for p->max_expected given this field must always be non-zero after this patch. Fixes: 12f7a505331e ("netfilter: add user-space connection tracking helper infrastructure") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nft_ct: expectation timeouts are passed in millisecondsFlorian Westphal1-3/+18
Userspace passes '5000' in case user asks for 5 seconds. Allowing for sub-second expectation lifetimes makes sense to me. so fix up the kernel side instead of munging nft to send a value rounded up to next second. Also note that this violates nft convention of passing integers in network byte order, but we can't change this anymore. Fixes: 857b46027d6f ("netfilter: nft_ct: add ct expectations support") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nf_conntrack_expect: run expectation eviction with no helperPablo Neira Ayuso1-0/+7
Run expectation eviction if no helper is specified to deal with the nft_ct expectation support. Cap the maximum expectation limit per master conntrack to NF_CT_EXPECT_MAX_CNT (255). Fixes: 857b46027d6f ("netfilter: nft_ct: add ct expectations support") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nf_conntrack_expect: store master_tuple in expectationPablo Neira Ayuso3-6/+7
Store master conntrack tuple in the expectation since exp->master might refer to a different conntrack when accessed from rcu read side lock area due to typesafe rcu rules. Fixes: 02a3231b6d82 ("netfilter: nf_conntrack_expect: store netns and zone in expectation") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: conntrack: add deprecation warnings for irc and pptp trackersFlorian Westphal3-5/+10
IRC Direct client-to-client requires plaintext. IRC over TLS should be preferred, making this helper ineffective. Add a deprecation warning and update the help text to better reflect that this is needed for the DCC extension, not IRC itself. PPTP is esoteric these days and it is the only helper that requires the destroy callback in the conntrack helper API. Removal would simplify the conntrack core. Both helpers are IPv4 only. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: ctnetlink: do not allow to reset helper on existing conntrackPablo Neira Ayuso1-13/+0
This feature allows to reset a helper for an existing conntrack, but it is not safe. This requires a synchronized_rcu() call after resetting the helper, which is going to be expensive for a large batch of conntrack entries. This also needs to call to the .destroy callback to release the GRE/PPTP mappings to fix it. This feature antedates the creation of the conntrack-tools and I cannot find a good use-case for this. Given that I cannot find any user in the netfilter.org userspace tree, I prefer to remove this feature. Fixes: c1d10adb4a52 ("[NETFILTER]: Add ctnetlink port for nf_conntrack") Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nft_compat: ebtables emulation must reject non-bridge targetsFlorian Westphal1-3/+21
xtables targets return netfilter verdicts: NF_ACCEPT, NF_DROP, and so on. ebtables targets return incompatible verdicts: EBT_ACCEPT, EBT_DROP, ... We cannot allow fallback to NFPROTO_UNSPEC. ebtables doesn't permit this since 11ff7288beb2 ("netfilter: ebtables: reject non-bridge targets") but that commit missed the nft_compat layer. Reported-by: Ren Wei <n05ec@lzu.edu.cn> Reported-by: Wyatt Feng <bronzed_45_vested@icloud.com> Reported-by: Yuan Tan <yuantan098@gmail.com> Reported-by: Yifan Wu <yifanwucs@gmail.com> Reported-by: Juefei Pu <tomapufckgml@gmail.com> Reported-by: Zhengchuan Liang <zcliangcn@gmail.com> Reported-by: Xin Liu <bird@lzu.edu.cn> Fixes: 0ca743a55991 ("netfilter: nf_tables: add compatibility layer for x_tables") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nft_synproxy: stop bypassing the priv->info snapshotRunyu Xiao1-5/+4
nft_synproxy_eval_v4() and nft_synproxy_eval_v6() already take a whole-object READ_ONCE() snapshot of the shared priv->info state before building the SYNACK reply, but nft_synproxy_tcp_options() still masks opts->options with priv->info.options from the live shared object. When a named synproxy object is updated concurrently with SYN traffic, the eval path can then mix mss and timestamp handling from the local snapshot with an options mask taken from a newer configuration, so one SYNACK no longer reflects a coherent synproxy configuration. Use info->options so nft_synproxy_tcp_options() stays on the same local snapshot that the eval path already copied from priv->info. Fixes: ee394f96ad75 ("netfilter: nft_synproxy: add synproxy stateful object support") Signed-off-by: Runyu Xiao <runyu.xiao@seu.edu.cn> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: flowtable: Validate iph->ihl in nf_flow_ip4_tunnel_proto()Lorenzo Bianconi1-3/+5
Add sanity check for iph->ihl field in nf_flow_ip4_tunnel_proto() before using it to compute the header size, avoiding out-of-bounds access with malformed IP headers. While at it, use iph->protocol instead of the hardcoded IPPROTO_IPIP constant when setting ctx->tun.proto and reference ctx->tun.hdr_size when updating ctx->offset. Fixes: ab427db178858 ("netfilter: flowtable: Add IPIP rx sw acceleration") Signed-off-by: Lorenzo Bianconi <lorenzo@kernel.org> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nf_conncount: prevent connlimit drops for early confirmed ctFernando Fernandez Mancera1-6/+5
Commit 69894e5b4c5e ("netfilter: nft_connlimit: update the count if add was skipped") introduced a regression where packets for valid connections are dropped when using connlimit for soft-limiting scenarios. The issue occurs when a new connection reuses a socket currently in the TIME_WAIT state. In this scenario, the connection tracking entry is evaluated as already confirmed. Previously, __nf_conncount_add() assumed that if a connection was confirmed and did not originate from the loopback interface, it should skip the addition and return -EEXIST. Skipping the addition triggers a garbage collection run that cleans up the TIME_WAIT connection. Consequently, the active connection count drops to 0, which xt_connlimit mishandles, leading to the false rejection of the perfectly valid new connection. Fix this by replacing the interface check with protocol-agnostic state checks. We now skip the tree insertion and preserve the lockless garbage collection optimization only if the connection is IPS_ASSURED. This allows early-confirmed setup packets (such as reused TIME_WAIT sockets or locally generated SYN-ACKs) to be properly evaluated and counted without falsely dropping. The goto check_connections path is maintained to ensure these setup packets are deduplicated correctly. This has been tested with slowhttptest and HTTP server configured locally to ensure we are not breaking soft-limiting scenarios for local or external connections. In addition, it was tested with a OVS zone limit too. Fixes: 69894e5b4c5e ("netfilter: nft_connlimit: update the count if add was skipped") Reported-by: Alejandro Olivan Alvarez <alejandro.olivan.alvarez@gmail.com> Closes: https://lore.kernel.org/netfilter-devel/177349610461.3071718.4083978280323144323@eldamar.lan/ Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-23netfilter: nf_nat: avoid invalid nat_net pointer use on failed nf_nat_init()Mathias Krause1-0/+10
We ran into below KASAN splat, which is mostly uninteresting, beside for having nf_nat_register_fn() in the call chain as a cause for the offending access: ================================================================== BUG: KASAN: slab-out-of-bounds in nf_nat_register_fn+0x5f9/0x640 Read of size 8 at addr ffff890031e54c20 by task iptables/9510 CPU: 0 UID: 0 PID: 9510 Comm: iptables Not tainted 6.18.18-grsec-full-20260320181326 #1 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: <TASK> […] dump_stack_lvl+0xee/0x160 ffff88004117eeb8 […] print_report+0x6e/0x640 ffff88004117eee0 […] ? __phys_addr+0x8e/0x140 ffff88004117eef0 […] ? kasan_addr_to_slab+0x51/0xe0 ffff88004117ef08 […] ? complete_report_info+0xec/0x1c0 ffff88004117ef20 […] ? nf_nat_register_fn+0x5f9/0x640 ffff88004117ef48 […] kasan_report+0xbc/0x140 ffff88004117ef50 […] ? nf_nat_register_fn+0x5f9/0x640 ffff88004117ef90 […] nf_nat_register_fn+0x5f9/0x640 ffff88004117eff8 […] ? nf_nat_icmp_reply_translation+0x6e0/0x6e0 ffff88004117f070 […] nf_tables_register_hook.part.0+0xa0/0x220 ffff88004117f080 […] nf_tables_addchain.constprop.0+0x1054/0x1fc0 ffff88004117f0b8 […] ? nft_chain_lookup.part.0+0x4ce/0xac0 ffff88004117f130 […] ? nf_tables_abort+0x3d80/0x3d80 ffff88004117f190 […] ? nf_tables_dumpreset_obj+0x100/0x100 ffff88004117f1c8 […] ? nft_table_lookup.part.0+0x255/0x300 ffff88004117f310 […] ? nf_tables_newchain+0x21a4/0x2fa0 ffff88004117f358 […] nf_tables_newchain+0x21a4/0x2fa0 ffff88004117f360 […] ? nf_tables_addchain.constprop.0+0x1fc0/0x1fc0 ffff88004117f458 […] ? nla_get_range_signed+0x4a0/0x4a0 ffff88004117f488 […] ? lock_acquire+0x16f/0x320 ffff88004117f490 […] ? find_held_lock+0x3b/0xe0 ffff88004117f4b0 […] ? __nla_parse+0x45/0x80 ffff88004117f500 […] nfnetlink_rcv_batch+0xbca/0x19a0 ffff88004117f550 […] ? nfnetlink_net_exit_batch+0x120/0x120 ffff88004117f618 […] ? __sanitizer_cov_trace_switch+0x63/0xe0 ffff88004117f720 […] ? gr_acl_handle_mmap+0x1c4/0x320 ffff88004117f7c0 […] ? nla_get_range_signed+0x4a0/0x4a0 ffff88004117f7e8 […] ? gr_is_capable+0x6f/0xe0 ffff88004117f830 […] ? __nla_parse+0x45/0x80 ffff88004117f860 […] ? skb_pull+0x103/0x1a0 ffff88004117f880 […] nfnetlink_rcv+0x3db/0x4a0 ffff88004117f8b0 […] ? nfnetlink_rcv_batch+0x19a0/0x19a0 ffff88004117f8d8 […] ? netlink_lookup+0xe2/0x240 ffff88004117f900 […] netlink_unicast+0x74b/0xb00 ffff88004117f930 […] ? netlink_attachskb+0xb20/0xb20 ffff88004117f980 […] ? __check_object_size+0x3e/0xaa0 ffff88004117f998 […] ? security_netlink_send+0x51/0x160 ffff88004117f9c8 […] netlink_sendmsg+0xa03/0x1200 ffff88004117f9f8 […] ? netlink_unicast+0xb00/0xb00 ffff88004117fa70 […] ? netlink_unicast+0xb00/0xb00 ffff88004117fac8 […] ? ____sys_sendmsg+0xe2a/0x1040 ffff88004117faf8 […] ____sys_sendmsg+0xe2a/0x1040 ffff88004117fb00 […] ? kernel_recvmsg+0x300/0x300 ffff88004117fb60 […] ? reacquire_held_locks+0xe9/0x260 ffff88004117fbc8 […] ___sys_sendmsg+0x138/0x200 ffff88004117fbf8 […] ? do_recvmmsg+0x7e0/0x7e0 ffff88004117fc30 […] ? lockdep_hardirqs_on_prepare+0x101/0x1e0 ffff88004117fc50 […] ? lock_acquire+0x16f/0x320 ffff88004117fd20 […] ? lock_acquire+0x16f/0x320 ffff88004117fd58 […] ? find_held_lock+0x3b/0xe0 ffff88004117fd70 […] __sys_sendmsg+0x17a/0x260 ffff88004117fdc8 […] ? __sys_sendmsg_sock+0x80/0x80 ffff88004117fdf0 […] ? syscall_trace_enter+0x15e/0x2c0 ffff88004117fe98 […] do_syscall_64+0x7d/0x400 ffff88004117fec8 […] entry_SYSCALL_64_safe_stack+0x4a/0x60 ffff88004117fef8 </TASK> ================================================================== The out-of-bounds report, though, is a red herring as it is for an access that shouldn't have happened in the first place. When nf_nat_init() fails to register its BPF kfuncs, it'll unwind and, among others, call unregister_pernet_subsys() to deregister its per-net ops. This makes the previously allocated net id available for reuse by the next caller of register_pernet_subsys(), in our case, synproxy. However, 'nat_net_id' will still hold the previously allocated value. If nf_nat.o gets build as a module, all this doesn't matter. A failed initialization routine makes the module fail to load and any dependent module won't be able to load either. However, if nf_nat.o is built-in, a failing init won't /completely/ make its functionality unavailable to dependent modules, namely the code and static data is still there, free to be called by modules like nft_chain_nat.ko. Case in point, nft_chain_nat registers hooks that'll call into nf_nat which, in our case, failed to initialize and therefore won't have a valid net id nor related net_nat object any more. Code in nf_nat, namely nf_nat_register_fn() and nf_nat_unregister_fn(), still making use of the reallocated net id, lead to a type confusion as the call to net_generic() will no longer return memory belonging to an object suited to fit 'struct nat_net' but 'struct synproxy_net' instead. The latter is only 24 bytes on 64-bit systems, much smaller than struct nat_net which is 176 bytes, perfectly explaining the OOB KASAN report. Detect and handle a failed nf_nat_init() by testing the 'nf_nat_hook' pointer which will be reset to NULL on initialization errors to prevent the usage of an invalid nat_net pointer. As this check is only needed when nf_nat.o is built-in, guard it by '#ifndef MODULE...'. Fixes: cbc1dd5b659f ("netfilter: nf_nat: Fix possible memory leak in nf_nat_init()") Signed-off-by: Mathias Krause <minipli@grsecurity.net> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
2026-06-22ipv6: Fix null-ptr-deref in fib6_nh_mtu_change().Xiang Mei1-0/+3
fib6_nh_mtu_change() re-fetches idev via __in6_dev_get(arg->dev) and dereferences idev->cnf.mtu6 without a NULL check. addrconf_ifdown() clears dev->ip6_ptr with RCU_INIT_POINTER() after rt6_disable_ip() has released tb6_lock, so the RA-driven MTU walk can observe a NULL idev and oops. The caller rt6_mtu_change_route() guards its own __in6_dev_get(), but this re-fetch is unguarded; nexthop-backed routes survive addrconf_ifdown()'s flush, so the walk still reaches it after ip6_ptr is nulled. Return 0 when idev is NULL, matching rt6_mtu_change_route() and the fib6_mtu() fix in commit 5ad509c1fdad ("ipv6: Fix null-ptr-deref in fib6_mtu()."). Oops: general protection fault, ... KASAN: null-ptr-deref in range [0x00000000000002a8-0x00000000000002af] RIP: 0010:fib6_nh_mtu_change+0x203/0x990 rt6_mtu_change_route+0x141/0x1d0 __fib6_clean_all+0xd0/0x160 rt6_mtu_change+0xb4/0x100 ndisc_router_discovery+0x24b5/0x2cb0 icmpv6_rcv+0x12e9/0x1710 ipv6_rcv+0x39b/0x410 Fixes: c0b220cf7d80 ("ipv6: Refactor exception functions") Reported-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260619045334.2427073-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-22bpf: Guard conntrack opts error writesYiyang Chen1-22/+13
The conntrack lookup and allocation kfuncs take an opts pointer together with an opts__sz argument. The verifier checks only the memory range described by opts__sz, but the wrappers unconditionally write opts->error whenever the internal lookup or allocation helper returns an error. For an invalid size smaller than the end of opts->error, that write can land outside the verifier-checked range. Keep returning NULL for invalid arguments, but only report the error through opts->error when the supplied size includes the field. This preserves error reporting for the supported 12-byte and 16-byte layouts, and for other invalid sizes that still include opts->error. Fixes: b4c2b9593a1c ("net/netfilter: Add unstable CT lookup helpers for XDP and TC-BPF") Fixes: d7e79c97c00c ("net: netfilter: Add kfuncs to allocate and insert CT") Signed-off-by: Yiyang Chen <chenyy23@mails.tsinghua.edu.cn> Link: https://lore.kernel.org/r/9535e781fe14449b1d4e9bbc3baa7566a93bf512.1781765747.git.chenyy23@mails.tsinghua.edu.cn Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-22Merge tag 'nf-26-06-21' of ↵Jakub Kicinski24-192/+233
git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf Pablo Neira Ayuso says: ==================== Netfilter fixes for net The following patchset contains Netfilter fixes for net. This batches fixes for real crashes with trivial/correctness fixes. There is too a rework of the conntrack expectation timeout strategy to deal with a possible race when removing an expectation. 1) Fix the incorrect flowtable timeout extension for entries in hw offload, from Adrian Bente. This is correcting a defect in the functionality, no crash. 2) Hold reference to device under the fake dst in br_netfilter, from Haoze Xie. This is fixing a possible UaF if the device is removed while packet is sitting in nfqueue. 3) Reject template conntrack in xt_cluster, otherwise access to uninitialize conntrack fields are possible leading to WARN_ON due to unset layer 3 protocol. From Wyatt Feng. 4) Make sure the IPv6 tunnel header is in the linear skb data area before pulling. While at it remove incomplete NEXTHDR_DEST support. From Lorenzo Bianconi. This possibly leading to crash if IPv4 header is not in the linear area. 5) Use test_bit_acquire in ipset hash set to avoid reordering of subsequent memory access. This is addressing a LLM related report, no crash has been observed. From Jozsef Kadlecsik. 6) Use test_bit_acquire in ipset bitmap set too, for the same reason as in the previous patch, from Jozsef Kadlecsik. 7) Call kfree_rcu() after rcu_assign_pointer() to address a possible UaF if kfree_rcu() runs inmediately, which to my understanding never happens. Never observed in practise, reported by LLM. Also from Jozsef Kadlecsik. 8) Use disable_delayed_work_sync() instead cancel_delayed_work_sync() to avoid that ipset GC handler re-queues work as reported by LLM. From Jozsef Kadlecsik. This is for correctness. 9) Restore the check in nft_payload for exceeding payloda offset over 2^16. From Florian Westphal. This fixes a silent truncation, not a big deal, but better be assertive and reject it. 10) Validate NFT_META_BRI_IIFHWADDR can only run from bridge prerouting. From Florian Westphal. Harmless but it could allow to read bytes from skb->cb. 11) Zero out destination hardware address during the flowtable path setup, also from Florian. This is a correctness fix, LLM points that possible infoleak can happen but topology to achieve it is not clear. 12) Skip IPv4 options if present when building the IPV4 reject reply. Otherwise bytes in the IPv4 options header can be sent back to origin where the ICMP header is being expected. Again from Florian Westphal. 13) Replace timer API for expectation by GC worker approach. This is implicitly fixing a race between nf_ct_remove_expectations() which might fail to remove the expectation due to timer_del() returning false because timer has expired and callback is being run concurrently. This fix is addressing a crash that has been already reported with a reproducer. 14) Check if br_vlan_get_pvid_rcu() fails, otherwise possible stack infoleak of 4-bytes. From Florian Westphal. * tag 'nf-26-06-21' of git://git.kernel.org/pub/scm/linux/kernel/git/netfilter/nf: netfilter: nft_meta_bridge: fix NFT_META_BRI_IIFPVID stack leak netfilter: nf_conntrack_expect: use conntrack GC to reap expectations netfilter: nf_reject: skip iphdr options when looking for icmp header netfilter: nft_flow_offload: zero device address for non-ether case netfilter: nft_meta_bridge: add validate callback for get operations netfilter: nft_payload: reject offsets exceeding 65535 bytes netfilter: ipset: make sure gc is properly stopped netfilter: ipset: fix order of kfree_rcu() and rcu_assign_pointer() netfilter: ipset: Don't use test_bit() in lockless RCU readers in bitmap types netfilter: ipset: Don't use test_bit() in lockless RCU readers in hash types netfilter: flowtable: fix and simplify IP6IP6 tunnel handling netfilter: xt_cluster: reject template conntracks in hash match netfilter: nf_queue: pin bridge device while NFQUEUE holds fake dst netfilter: flowtable: fix offloaded ct timeout never being extended ==================== Link: https://patch.msgid.link/20260620222738.112506-1-pablo@netfilter.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21bpf: zero-initialize the fib lookup flow structAvinash Duduskar1-2/+2
bpf_ipv4_fib_lookup() and bpf_ipv6_fib_lookup() build the flow key on the stack with a bare "struct flowi4 fl4;" / "struct flowi6 fl6;" and fill it field by field, but never set flowi4_l3mdev / flowi6_l3mdev. On the non-DIRECT path the lookup goes through the fib rules whenever the netns has custom rules, which a VRF installs: bpf_ipv4_fib_lookup() -> fib_lookup() -> __fib_lookup() -> l3mdev_update_flow() reads !fl->flowi_l3mdev -> fib_rules_lookup() -> fib_rule_match() -> l3mdev_fib_rule_match() uses fl->flowi_l3mdev l3mdev_update_flow() resolves the l3mdev master from the ingress device only while the field is still zero. Left at a nonzero stack value the resolution is skipped, and l3mdev_fib_rule_match() then tests that value as an ifindex, so the VRF master is not resolved and the rule fails to match: an ingress enslaved to a VRF can fail to select its table. FIB rules matching on an L3 master device (l3mdev_fib_rule_iif_match()/ _oif_match()) read the same value, so an "ip rule iif/oif <vrf>" mismatches the same way. Zero-initialize the whole flow struct rather than adding one more field assignment, so any flowi field added later is covered too. ip_route_input_slow() likewise zeroes the field before its input lookup. CONFIG_INIT_STACK_ALL_ZERO masks this by default, but it depends on compiler support (CC_HAS_AUTO_VAR_INIT_ZERO), so INIT_STACK_NONE builds, including older toolchains that fall back to it, are exposed. Built with INIT_STACK_ALL_PATTERN, a plain bpf_fib_lookup (no VLAN, no DIRECT) over a VRF slave whose destination is routed only in the VRF table returns BPF_FIB_LKUP_RET_NOT_FWDED, and resolves with this patch. On the default config the lookup succeeds either way, so ordinary testing does not catch the bug. Fixes: 40867d74c374 ("net: Add l3mdev index to flow struct and avoid oif reset for port devices") Signed-off-by: Avinash Duduskar <avinash.duduskar@gmail.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20260617224719.1428599-1-avinash.duduskar@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-21bpf: Fix partial copy of non-linear test_run outputSun Jian1-6/+2
For non-linear test_run output, bpf_test_finish() derives the linear data copy length from copy_size - frag_size. This only matches the linear data length when copy_size is the full packet size. When userspace provides a short data_out buffer, copy_size is clamped to that buffer size. If copy_size is smaller than frag_size, the computed length becomes negative and bpf_test_finish() returns -ENOSPC before copying the packet prefix or updating data_size_out. Compute the linear data length from the packet layout instead, and clamp the linear copy length to copy_size. This preserves the expected partial-copy semantics: return -ENOSPC, copy the packet prefix that fits in data_out, and report the full packet length through data_size_out. Fixes: 7855e0db150ad ("bpf: test_run: add xdp_shared_info pointer in bpf_test_finish signature") Signed-off-by: Sun Jian <sun.jian.kdev@gmail.com> Acked-by: Paul Chaignon <paul.chaignon@gmail.com> Link: https://lore.kernel.org/r/20260617093557.63880-2-sun.jian.kdev@gmail.com Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2026-06-21ipv6: ioam: fix type confusion of dst_entryJiayuan Chen1-4/+4
IOAM uses a dummy dst_entry(null_dst) to mark that the destination should not be changed after the transformation. This dst is stored in the IOAM lwt state and may be passed to dst_cache_set_ip6(). However, the IPv6 dst cache path eventually calls rt6_get_cookie(), which treats the dst_entry as part of a struct rt6_info. Since the null_dst was embedded directly as a struct dst_entry in struct ioam6_lwt, this resulted in an invalid cast and rt6_get_cookie() reading fields from the wrong object. In practice, the wrong cookie is not used while dst->obsolete is zero, but rt6_get_cookie() may also access per-cpu value when rt->sernum is zero. In this case, rt->sernum aliases ioam6_lwt::cache::reset_ts, which can become zero, making this a potential invalid pointer access. Fix this by embedding a full struct rt6_info for the dummy IPv6 route and passing its dst member to the dst APIs. Fixes: 47ce7c854563 ("net: ipv6: ioam6: fix double reallocation") Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Justin Iurman <justin.iurman@gmail.com> Link: https://patch.msgid.link/20260618104336.48934-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21ipv6: account for fraggap on the paged allocation pathWongi Lee1-6/+3
In __ip6_append_data(), when the paged-allocation branch is taken (MSG_MORE / NETIF_F_SG / large fraglen), alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap (datalen = length + fraggap). When fraggap is non-zero, this is not the first skb and transhdrlen is zero. The fraggap bytes carried over from the previous skb are copied just past the fragment headers in the new skb's linear area. The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount, and the copy writes past skb->end into the trailing skb_shared_info. An unprivileged user can trigger this via a UDPv6 socket using MSG_MORE together with MSG_SPLICE_PAGES. The bad accounting was introduced by commit 773ba4fe9104 ("ipv6: avoid partial copy for zc"). Before commit ce650a166335 ("udp6: Fix __ip6_append_data()'s handling of MSG_SPLICE_PAGES"), the negative copy value caused -EINVAL to be returned. That later commit allowed MSG_SPLICE_PAGES to proceed in this case, making the corruption triggerable. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Since a negative copy is no longer expected for a valid MSG_SPLICE_PAGES case, remove the MSG_SPLICE_PAGES exception from the negative copy check. Fixes: 773ba4fe9104 ("ipv6: avoid partial copy for zc") Signed-off-by: Jungwoo Lee <jwlee2217@gmail.com> Signed-off-by: Wongi Lee <qw3rtyp0@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/ajFTqRljatR17fFy@DESKTOP-19IMU7U.localdomain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21ipv4: account for fraggap on the paged allocation pathWongi Lee1-5/+2
In __ip_append_data(), when the paged-allocation branch is taken, alloclen and pagedlen are computed as alloclen = fragheaderlen + transhdrlen; pagedlen = datalen - transhdrlen; datalen already includes fraggap, but the fraggap bytes carried over from the previous skb are copied into the new skb's linear area at offset transhdrlen by the subsequent skb_copy_and_csum_bits(). The linear area is therefore undersized by fraggap bytes while pagedlen is overstated by the same amount. The non-paged branch sets alloclen to fraglen, which already accounts for fraggap because datalen does. Bring the paged branch in line by adding fraggap to alloclen and subtracting it from pagedlen. After this adjustment, copy no longer collapses to -fraggap on the paged path, so remove the stale comment describing that old arithmetic. Fixes: 8eb77cc73977 ("ipv4: avoid partial copy for zc") Signed-off-by: Jungwoo Lee <jwlee2217@gmail.com> Signed-off-by: Wongi Lee <qw3rtyp0@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/ajFR1eLAIs42TN3g@DESKTOP-19IMU7U.localdomain Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21net/sched: dualpi2: fix GSO backlog accountingXingquan Liu1-6/+5
When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued. With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference. Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued. Fixes: 8f9516daedd6 ("sched: Add enqueue/dequeue of dualpi2 qdisc") Cc: stable@vger.kernel.org Signed-off-by: Xingquan Liu <b1n@b1n.io> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Reviewed-by: Victor Nogueira <victor@mojatatu.com> Link: https://patch.msgid.link/20260619151447.223640-1-b1n@b1n.io Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21ipv6: ndisc: fix NULL deref in accept_untracked_na()Weiming Shi1-5/+3
accept_untracked_na() re-fetches the inet6_dev with __in6_dev_get(dev) and dereferences idev->cnf.accept_untracked_na without a NULL check, even though its only caller ndisc_recv_na() already fetched and NULL-checked idev for the same device. Both reads of dev->ip6_ptr run in the same RCU read-side critical section, but a concurrent addrconf_ifdown() can clear dev->ip6_ptr between them: lowering the MTU below IPV6_MIN_MTU calls addrconf_ifdown() without the synchronize_net() that orders the unregister path, so the re-fetch returns NULL and oopses: BUG: KASAN: null-ptr-deref in ndisc_recv_na (net/ipv6/ndisc.c:974) Read of size 4 at addr 0000000000000364 Call Trace: <IRQ> ndisc_recv_na (net/ipv6/ndisc.c:974) icmpv6_rcv (net/ipv6/icmp.c:1193) ip6_protocol_deliver_rcu (net/ipv6/ip6_input.c:479) ip6_input_finish (net/ipv6/ip6_input.c:534) ip6_input (net/ipv6/ip6_input.c:545) ip6_mc_input (net/ipv6/ip6_input.c:635) ipv6_rcv (net/ipv6/ip6_input.c:351) </IRQ> It is reachable by an unprivileged user via a network namespace. Pass the caller's already validated idev instead of re-fetching it; the idev stays alive for the whole RCU critical section, so it is safe even after dev->ip6_ptr has been cleared. Fixes: aaa5f515b16b ("net: ipv6: new accept_untracked_na option to accept na only if in-network") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: Jiayuan Chen <jiayuan.chen@linux.dev> Link: https://patch.msgid.link/20260617065512.2529757-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21net: sit: require CAP_NET_ADMIN in the device netns for changelinkMaoyi Xie1-0/+3
ipip6_changelink() operates on at most two netns, dev_net(dev) and the tunnel link netns t->net. They differ once the device is created in or moved to a netns other than the one the request runs in. The rtnl changelink path checks CAP_NET_ADMIN only against dev_net(dev), so a caller privileged there but not in t->net can rewrite a tunnel that lives in t->net. Gate ipip6_changelink() on rtnl_dev_link_net_capable() at its top, before any attribute is parsed. sit was the one tunnel type not covered by the recent series that added this check to the other changelink() handlers. Fixes: 5e6700b3bf98 ("sit: add support of x-netns") Link: https://lore.kernel.org/netdev/20260612085941.3158249-1-maoyixie.tju@gmail.com/ Cc: stable@vger.kernel.org Signed-off-by: Maoyi Xie <maoyixie.tju@gmail.com> Reviewed-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260618070817.3378283-1-maoyixie.tju@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-21net/sched: act_ct: fix nf_connlabels leak on two error pathsMichael Bommarito1-2/+4
tcf_ct_fill_params() calls nf_connlabels_get() (setting put_labels) when TCA_CT_LABELS is present, but two later error sites use a bare return instead of "goto err", skipping the err: nf_connlabels_put() cleanup. They also precede the "p->put_labels = put_labels" assignment, so the tcf_ct_params_free() fallback does not release the count either. Each failed RTM_NEWACTION on these paths leaks one nf_connlabels reference: net->ct.labels_used is incremented and never released. The action is reachable with CAP_NET_ADMIN over the netns, i.e. from an unprivileged user namespace on default-userns kernels. Impact: an unprivileged user with CAP_NET_ADMIN over a network namespace (e.g. via user namespaces) leaks one nf_connlabels reference per failed RTM_NEWACTION on the two error paths; net->ct.labels_used is never released. The err: label is safe to reach from both sites: p->tmpl is still NULL there (kzalloc'd, not yet assigned) and nf_ct_put(NULL) is a no-op, so no inline release is needed. Fixes: 70f06c115bcc ("sched: act_ct: switch to per-action label counting") Signed-off-by: Michael Bommarito <michael.bommarito@gmail.com> Acked-by: Jamal Hadi Salim <jhs@mojatatu.com> Link: https://patch.msgid.link/20260617215708.1115818-1-michael.bommarito@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>