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4 daysvxlan: vnifilter: validate the VXLAN_VNIFILTER_ENTRY nestAli Firas
vxlan_vnifilter_process() parses the message with vni_filter_policy, whose VXLAN_VNIFILTER_ENTRY is a bare NLA_NESTED with no nested policy attached. The entry attributes are therefore validated only later, one entry at a time, by the nla_parse_nested() inside vxlan_process_vni_filter(). Entries are parsed as they are dispatched: in a message whose first entry is valid and whose second is not, the first entry is applied and its RTM_NEWTUNNEL notification sent before the second is rejected. Link the nest to vni_filter_entry_policy with NLA_POLICY_NESTED() so every entry is checked against the entry policy up front, before any entry is acted on. A message whose entry the policy rejects -- a malformed attribute, or, with the next patch, an out-of-range endpoint -- is now refused as a unit and installs nothing. Faults the policy does not cover, such as a device or handler error raised on a later entry, are unchanged: entries are still dispatched and applied one at a time. This reorders two faults. The nest is validated before the device is looked up and before the vnifilter flag is checked, so a request rejected by the entry policy, aimed at a missing or non-vnifilter device, now returns that policy error where it previously returned -ENODEV or -EOPNOTSUPP. The request was invalid either way; only the errno an operator sees changes. The nla_parse_nested() in vxlan_process_vni_filter() stays: it is what fills the per-entry attribute table the handler reads. It can no longer fail on a message that has reached it. Suggested-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/netdev/20260921150904.65a704eb@kernel.org/ Signed-off-by: Ali Firas <alishmery18@gmail.com> Link: https://patch.msgid.link/20261014123814.388557-2-alishmery18@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07vxlan: report a circular route as SKB_DROP_REASON_RECURSION_LIMITAnton Danilov
udp_tunnel_dst_lookup() and udp_tunnel6_dst_lookup() return -ELOOP when the route to the remote end goes out of the vxlan device itself, and vxlan_xmit_one() counts that in collisions, apart from the -ENETUNREACH of a failed lookup. The drop reason does not tell them apart: both are reported as SKB_DROP_REASON_IP_OUTNOROUTES, which describes a failed route lookup. Such a route would send the encapsulated packet back into the device it leaves, which is the dead loop on a virtual device that SKB_DROP_REASON_RECURSION_LIMIT describes. Report the -ELOOP case with that reason, and add the tunnel case to the description of the reason as an example. ip_tunnel and ip6_tunnel make the same check, rt->dst.dev == dev in ip_tunnel_xmit() and ip_md_tunnel_xmit() and tdev == dev in ip6_tnl_xmit(), and can report it with the same reason. Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261005201417.906344-5-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07vxlan: report the drop reason of __iptunnel_pull_header()Anton Danilov
vxlan_rcv() reports SKB_DROP_REASON_NOMEM whenever __iptunnel_pull_header() fails, as the helper used to return -ENOMEM for any failure. The VXLAN header is already in the linear area at this point, but the inner Ethernet header of a packet without GPE may not be, so a packet whose inner frame is shorter than an Ethernet header is reported as an out of memory condition. Report the reason __iptunnel_pull_header() now returns instead: PKT_TOO_SMALL for such a packet, NOMEM when an allocation fails. Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261005201417.906344-4-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07vxlan: rename the drop reasons for use by other tunnelsAnton Danilov
VXLAN_INVALID_HDR and VXLAN_VNI_NOT_FOUND describe conditions that are not specific to vxlan: a malformed tunnel header, and a packet for which no tunnel device is found. The GRE receive paths drop packets for the same two conditions, and can report them with the same reasons once they are converted to drop reasons. Rename them to TUNNEL_INVALID_HDR and TUNNEL_NOT_FOUND and reword their descriptions, the way VXLAN_NO_REMOTE became NO_TX_TARGET in commit 46e0ccfb88f0 ("net: vxlan: rename SKB_DROP_REASON_VXLAN_NO_REMOTE"). The numeric values stay the same; the names that the skb:kfree_skb tracepoint and drop_monitor report change. Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Anton Danilov <littlesmilingcloud@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261005201417.906344-2-littlesmilingcloud@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07ipv4: Use ipv4_neigh_lookup() and friends.Kuniyuki Iwashima
It is error-prone to require callers to fetch netns and neigh_table and pass it with dev to neigh_lookup(), etc. Let's replace neigh_lookup() and friends with IPv4 helpers. Note that __neigh_lookup(create=false) is replaced with ipv4_neigh_lookup() and __neigh_lookup(create=true) and __neigh_lookup_errno() are split into ipv4_neigh_lookup() and ipv4_neigh_create(). Fixes: 2430df635a59 ("ipv4: Replace &arp_tbl with arp_table(net).") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261003212336.1304988-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-10-07ipv6: Use ipv6_neigh_lookup() and friends.Kuniyuki Iwashima
syzbot reported the splat below in neigh_mark_dead() [0] where tbl->lock was not held while neigh_ifdown() should have acquired one. This only happens when a neigh_table accidentally has a neighbour from a different netns. In ip6_finish_output2(), the net argument is the caller's and does not always match dev_net(dev) fetched from dst. (e.g. xfrm) It is error-prone to require callers to fetch netns and neigh_table and pass it with dev to neigh_lookup(), etc. Let's replace neigh_lookup() and friends with IPv6 helpers. Note that __neigh_lookup() is split into ipv6_neigh_lookup() and ipv6_neigh_create(). [0]: debug_locks && !(lock_is_held(&(&n->tbl->lock)->dep_map) != 0) WARNING: net/core/neighbour.c:154 at neigh_mark_dead+0x2fb/0x340 net/core/neighbour.c:154, CPU#0: syz.0.857/9765 Modules linked in: CPU: 0 UID: 0 PID: 9765 Comm: syz.0.857 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:neigh_mark_dead+0x2fb/0x340 net/core/neighbour.c:154 Code: e8 03 42 80 3c 28 00 74 08 48 89 df e8 ee 9a 80 f8 4c 89 33 5b 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc e8 86 95 10 f8 90 <0f> 0b 90 e9 8f fd ff ff 48 c7 c1 80 9a 7a 90 80 e1 07 80 c1 03 38 RSP: 0018:ffffc90003726600 EFLAGS: 00010287 RAX: ffffffff89b7467a RBX: ffff888022e86000 RCX: 0000000000080000 RDX: ffffc900047fa000 RSI: 0000000000003e08 RDI: 0000000000003e09 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520006e4cb8 R12: ffff888022e8613c R13: dffffc0000000000 R14: ffff888022e86020 R15: ffff888022e86000 FS: 00007f9c30f046c0(0000) GS:ffff888124cc6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000076c56000 CR4: 00000000003526f0 Call Trace: <TASK> neigh_flush_one+0x27c/0x5a0 net/core/neighbour.c:388 neigh_flush_dev net/core/neighbour.c:432 [inline] __neigh_ifdown+0x1fb/0xc70 net/core/neighbour.c:465 neigh_ifdown+0x1f/0x30 net/core/neighbour.c:487 rt6_disable_ip+0x751/0x7e0 net/ipv6/route.c:5058 addrconf_ifdown+0x155/0x1ad0 net/ipv6/addrconf.c:3892 addrconf_notify+0x1bc/0x1050 net/ipv6/addrconf.c:-1 notifier_call_chain+0x1a5/0x3d0 kernel/notifier.c:85 call_netdevice_notifiers_mtu net/core/dev.c:2350 [inline] netif_set_mtu_ext+0x5ac/0x830 net/core/dev.c:9963 do_setlink+0xa81/0x47a0 net/core/rtnetlink.c:3247 rtnl_setlink+0x578/0x820 net/core/rtnetlink.c:3623 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:7159 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2572 netlink_unicast_kernel net/netlink/af_netlink.c:1335 [inline] netlink_unicast+0x7bd/0x940 net/netlink/af_netlink.c:1361 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1916 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:800 __sock_sendmsg net/socket.c:815 [inline] sock_write_iter+0x2de/0x3e0 net/socket.c:1266 do_iter_readv_writev+0x612/0x8c0 fs/read_write.c:-1 vfs_writev+0x343/0x990 fs/read_write.c:1058 do_writev+0x154/0x2e0 fs/read_write.c:1104 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f9c2ff9e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f9c30f04028 EFLAGS: 00000246 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007f9c30225fa0 RCX: 00007f9c2ff9e159 RDX: 0000000000000001 RSI: 00002000000003c0 RDI: 0000000000000004 RBP: 00007f9c3003506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9c30226038 R14: 00007f9c30225fa0 R15: 00007ffed3c74808 </TASK> Fixes: df5f4f372de5 ("ipv6: Replace &nd_tbl with nd_table(net).") Reported-by: syzbot+5a8857f0b4a0a7b12c62@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6abd69a9.80e1c6cc.22483f.0005.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20261003212336.1304988-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: no longer rely on RTNL in vxlan_fill_info()Eric Dumazet
Now that vxlan->cfg is RCU-protected, we can update vxlan_fill_info() to run under RCU read lock instead of relying on RTNL. This completes the transition to RTNL-less link info dumping for VXLAN. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-9-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: remove default_dst and use vxlan_config and lowerdevEric Dumazet
Now that vxlan->cfg is an RCU-protected pointer, storing default destination attributes (remote_ip, remote_vni, remote_ifindex) in vxlan->default_dst is redundant and creates potential data races for lockless readers. Furthermore, several fields of struct vxlan_rdst (remote_port, offloaded, list, rcu, dst_cache) in default_dst were completely unused. The remaining one, remote_dev, only tracked the lower device, a role now taken by vxlan->lowerdev, so drop it from struct vxlan_rdst. Replace vxlan->default_dst with a 'struct net_device *lowerdev' pointer in struct vxlan_dev to track adjacent upper/lower netdev topology under RTNL, and switch all remaining users over to reading configuration attributes from vxlan->cfg. Also update mlx5e_tc_tun_get_remote_ifindex() to read remote_ifindex from vxlan->cfg under rcu_read_lock(). In vxlan_changelink(), pass lowerdev to vxlan_config_apply() to preserve needed_headroom and needed_tailroom. The mtu is still only reconsidered when the lower device changes, so that an unrelated changelink can not shrink it. cfg->remote_ifindex is now committed unconditionally, where default_dst.remote_ifindex was left untouched when IFLA_VXLAN_LINK was cleared, so a changelink dropping the lower device no longer leaves a stale ifindex behind. For the same reason vxlan_changelink() no longer needs to compute the ifindex that will actually be committed. Setting IFLA_VXLAN_LINK to 0 now also tears down the upper/lower adjacency, which netdev_adjacent_change_commit() used to skip for a NULL new device, resets needed_tailroom, and is rejected if per-VNI multicast groups are configured. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-8-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: convert configuration to RCU protectionEric Dumazet
Move 'struct vxlan_config' from an embedded structure inside 'struct vxlan_dev' to a dynamically allocated RCU-protected pointer 'vxlan->cfg'. Updating configuration via vxlan_changelink() or vxlan_dev_configure() allocates a new struct vxlan_config and publishes it with rcu_assign_pointer(), freeing the previous config with kfree_rcu(). Readers are converted to use rcu_dereference() or rtnl_dereference(). In vxlan_xmit(), acquire rcu_read_lock() to protect config access. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-7-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: move VXLAN_F_MDB to struct vxlan_dev flagsEric Dumazet
VXLAN_F_MDB is an internal runtime state flag indicating whether any MDB entries are configured on the device, rather than a netlink configuration attribute. In preparation for converting vxlan->cfg to an RCU-protected pointer, move VXLAN_F_MDB from struct vxlan_config to a dedicated 'flags' field in struct vxlan_dev as VXLAN_DEV_F_MDB, using atomic bitops (set_bit(), clear_bit(), test_bit()) to avoid KCSAN data races between the TX path and RTNL operations. This avoids having to dynamically reallocate and publish a new vxlan_config structure via RCU whenever the first MDB entry is added or the last one is removed, and prevents potential memory allocation failures during MDB teardown under memory pressure. mlxsw validates cfg->flags against a deny-by-default mask, so VXLAN_F_MDB used to make mlxsw_sp_nve_vxlan_can_offload() reject a device with MDB entries as carrying an unsupported flag. Add an explicit VXLAN_DEV_F_MDB test there to keep that rejection, with a message naming the actual reason. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: pass vxlan_config pointer to helper functionsEric Dumazet
In preparation for converting vxlan->cfg to an RCU-protected pointer, refactor internal helper functions in the RX, TX, MDB, and VNIFILTER paths to accept a pointer to struct vxlan_config (or pass flags/ saddr_family where appropriate) rather than directly accessing vxlan->cfg. No functional changes. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: vnifilter: signal interrupted RTM_GETTUNNEL dumpsEric Dumazet
vxlan_vnifilter_dump() walks all vxlan devices of a netns, and for each one walks vg->vni_list. Both cursors are plain ordinals stored in cb->args[0] and cb->args[1], and RTNL is released between dump skbs. A concurrent __vxlan_vni_add_list(), which inserts sorted by VNI, __vxlan_vni_del_list(), or an in-place group update in vxlan_vni_update() (which splits or merges coalesced VNI ranges) shifts the second cursor, duplicating or skipping entries. Unregistering a vxlan device shifts the first one, and the partially dumped device is then skipped altogether by the "if (idx < s_idx)" test, silently losing the rest of its VNIs. Add a per-netns generation counter, bumped whenever the set of vxlan devices in the netns or any vni_list changes, and feed it to nl_dump_check_consistent() so that user space gets NLM_F_DUMP_INTR and can retry, as vxlan_mdb_dump() already does. The counter is keyed on dev_net(vxlan->dev) rather than vxlan->net, because the dump enumerates devices with for_each_netdev_rcu() in the netns the netdevice lives in, which differs from the packet i/o netns when the device was created with a separate link netns. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260922181102.3989489-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: vnifilter: use list_for_each_entry_rcu() in vxlan_vnifilter_dump_dev()Eric Dumazet
RTM_GETTUNNEL dumps currently run under RTNL lock, but vxlan_vnifilter_dump() also acquires rcu_read_lock(). 1) Currently vxlan_vnifilter_dump_dev() traverses vg->vni_list using list_for_each_entry_safe(). Even though RTNL is held today, writers modify vg->vni_list with list_add_rcu() and list_del_rcu(). Switch to list_for_each_entry_rcu() for proper RCU traversal and as preparation for future lockless dump support. 2) During a paginated dump, RTNL is released between dump skbs. If vxlan_vnifilter_dump_dev() returns early because VXLAN_F_VNIFILTER is not set or vg has no VNIs, cb->args[1] was not cleared. This leaked a non-zero VNI offset to subsequent devices, silently skipping their first N VNIs. Furthermore, if devices are added or removed between dump calls, ordinal device indexes can shift. Track the current device ifindex in cb->args[2] and reset cb->args[1] if the device changes. Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260922181102.3989489-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-28vxlan: update default fdb entries when the lower device changesEric Dumazet
vxlan_changelink() only refreshed the default fdb entries when the remote IP changed, but vxlan_config_apply() also updates default_dst.remote_ifindex when the lower device changes. A changelink that only swaps the lower device therefore left the all zeros mac rdst pointing at the old ifindex: ip link add vxlan0 type vxlan id 10 group 239.1.1.1 dev eth0 ip link set dev vxlan0 type vxlan group 239.1.1.1 dev eth1 vxlan_xmit_one() uses rdst->remote_ifindex as the route oif, so traffic kept leaving eth0. VNI filter entries have the same problem, and are worse: their fdb entries are keyed on the device remote_ifindex even when the vni carries its own group, but vxlan_vnilist_update_group() only visited the vnis without one. vxlan_vni_delete_group() later looks an entry up with the current remote_ifindex, and vxlan_fdb_find_rdst() requires an exact match, so the lookup failed and the entry survived the delete. Re-adding the same vni then appended a second rdst, duplicating transmitted BUM traffic. Likewise, in vxlan_vni_update_group(), oldrip was only set when newrip was NULL, so changing an existing VNI's group appended the new rdst without deleting the old one. Set oldrip to the previous effective remote IP whenever updating an existing VNI (!create). Pass the old and new ifindex down to vxlan_update_default_fdb_entry() so the append targets the new lower device and the delete still matches the entry created for the old one, and refresh every vni rather than only those inheriting the device group. If updating the vni list fails partway through, unwind the already updated fdb entries (still deleting the new rdst even if re-adding the old one fails) so default_dst and the fdb entries do not diverge. Also run vxlan_multicast_leave() and vxlan_multicast_join() when VXLAN_F_VNIFILTER is set so per-VNI multicast memberships are migrated even when the device default remote_ip is not multicast, and make vxlan_multicast_leave_vnigrp() skip the default group and ignore -EADDRNOTAVAIL when multiple VNIs share a multicast group. The new ifindex is the one vxlan_config_apply() will commit, which is the current one when lowerdev is NULL, so that default_dst and the fdb entries can not diverge. Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260922181102.3989489-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-24Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.3-rc5). Conflicts: drivers/net/mdio/mdio-realtek-rtl9300.c 89a8a1eef2d44 ("net: mdio: realtek-rtl9300: fix RTL931x C22 extended page selection") cc3cb8db1eef9 ("net: mdio: realtek-rtl9300: Add page tracking") https://lore.kernel.org/arUZOqy73bE2pp0w@sirena.org.uk net/8021q/vlan_dev.c cd5dd68267c4 ("vlan: ensure sufficient headroom in vlan_dev_hard_header()") ca6ff8dd70eb ("vlan: annotate data-races in vlan_dev_priv fields") Adjacent changes: net/ipv6/ip6_gre.c dd47bcf279f1 ("ip6_gre: Call ip6erspan_tunnel_unlink_md() in ip6erspan_changelink().") cce829e2aa1d ("ip6_gre: Protect ip6gre_net.tunnels[][] with mutex.") drivers/net/ethernet/meta/fbnic/fbnic_txrx.c b5d9e9d4d0c1 ("eth: fbnic: use the Rx queue napi pointer to find the napi vector") c0aca269ec07 ("eth: fbnic: Make Rx completion coalescing configurable") drivers/net/ethernet/stmicro/stmmac/stmmac_selftests.c d68acbf93531 ("net: stmmac: selftests: Support running selftests on DSA conduits") 85ca3292d7a3 ("net: stmmac: Remove ARP offload code") drivers/net/ethernet/wangxun/libwx/wx_hw.c 3173cba11701 ("net: libwx: fix races in Tx timestamp handling") 7042c8c193e5 ("net: libwx: rename wx_pf_flags to wx_flags") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-23vxlan: use one headroom snapshot for neighbour repliesSanghyun Park
vxlan_na_create() samples LL_RESERVED_SPACE() to size the reply skb and then samples it again to reserve headroom. A concurrent vxlan_changelink() can update needed_headroom between the two reads, creating a TOCTOU race. The second value can exceed the allocation and make the Ethernet header write out of bounds. The race is reproducible on the unpatched kernel. It occurred when vxlan_na_create() generated a neighbour reply while vxlan_changelink() changed the link headroom. KASAN caught a four-byte write two bytes beyond a 704-byte skbuff_small_head allocation. Snapshot the headroom once and use that value for both allocation and reservation. Fixes: 4b29dba9c085 ("vxlan: fix nonfunctional neigh_reduce()") Signed-off-by: Sanghyun Park <sanghyun.park.cnu@gmail.com> Link: https://patch.msgid.link/20260918032842.502409-2-sanghyun.park.cnu@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-10Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.3-rc3). Conflicts: drivers/net/dsa/mt7530.c 3c18e3c9a54e ("net: dsa: mt7530: populate lpi_interfaces to fix EEE support") 10d9d8328e8a ("net: dsa: mt7530: replace mt7530_read with regmap_read") Adjacent changes: drivers/net/bonding/bond_alb.c 1746ef2e2df2 ("bonding: use skb_cow_head() in bond_do_alb_xmit() and rlb_arp_xmit()") 4cef95f72bbd ("bonding: fix u32 overflow in compute_gap()") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-09vxlan: initialize _md in vxlan_xmit_one()Eric Dumazet
If a VXLAN device is configured with both VXLAN_F_COLLECT_METADATA and VXLAN_F_GBP, and a packet is transmitted through it using an external ip_tunnel_info that lacks the IP_TUNNEL_VXLAN_OPT_BIT flag, md is left pointing to the uninitialized _md stack variable: if (test_bit(IP_TUNNEL_VXLAN_OPT_BIT, info->key.tun_flags)) { if (info->options_len < sizeof(*md)) goto drop; md = ip_tunnel_info_opts(info); } Because IP_TUNNEL_VXLAN_OPT_BIT is not set, md is not updated and remains pointing to _md. Later, vxlan_build_skb() is called with md, which eventually calls vxlan_build_gbp_hdr(): if (vxflags & VXLAN_F_GBP) vxlan_build_gbp_hdr(vxh, md); Inside vxlan_build_gbp_hdr(), md->gbp is read: if (!md->gbp) return; gbp = (struct vxlanhdr_gbp *)vxh; ... if (md->gbp & VXLAN_GBP_DONT_LEARN) gbp->dont_learn = 1; If the stack contains garbage, this causes: 1) VXLAN_HF_GBP flag to be spuriously set in the VXLAN header. 2) gbp->dont_learn and gbp->policy_applied to be set from stack bits. 3) gbp->policy_id to receive 16 bits of uninitialized kernel stack data, leaking it onto the wire. Fix this by zero-initializing _md. If IP_TUNNEL_VXLAN_OPT_BIT is not present, md->gbp remains 0, and vxlan_build_gbp_hdr() returns early without modifying the VXLAN header. Fixes: ee122c79d422 ("vxlan: Flow based tunneling") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260906180111.1973188-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-04vxlan: reject dynamic fdb entries that reference a nexthop idSeungwon Bae
The commit cited in the Fixes tag allowed VXLAN FDB entries to point to FDB nexthops so that overlay traffic could be load balanced across multiple VTEPs. Such entries can only be configured from user space, cannot be learned and cannot roam. They only make sense with a user space control plane such as E-VPN where data plane learning is disabled. Despite that, the VXLAN driver does not currently prevent such entries from being configured with the "dynamic" flag. The per-nexthop FDB list is only protected by the per-device hash lock, which is not sufficient when two VXLAN devices point to the same FDB nexthop and therefore share the list. Aging runs in softirq context without RTNL, so an entry deleted by one device can race with an addition or deletion from the other, leading to list corruption: list_del corruption. next->prev should be ffff8881069d9548, but was dead000000000122. (next=ffff8881069d9448) WARNING: CPU: 0 PID: 90 at lib/list_debug.c:65 __list_del_entry_valid_or_report+0x1aa/0x210 ... vxlan_fdb_destroy+0x5b8/0xad0 vxlan_cleanup+0x328/0x450 call_timer_fn+0x2a/0x1c0 run_timer_softirq+0x18c/0x210 BUG: KASAN: slab-use-after-free in vxlan_fdb_destroy Fix this by rejecting the bogus configuration of dynamic FDB entries that point to FDB nexthops, both when created and when an existing entry is updated. As such, the per-nexthop FDB list is only ever mutated under the RTNL lock. Add test cases to make sure that this does not regress in the future. Fixes: 1274e1cc4226 ("vxlan: ecmp support for mac fdb entries") Suggested-by: Ido Schimmel <idosch@nvidia.com> Signed-off-by: Seungwon Bae <qotmddnjs@ajou.ac.kr> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902155956.296699-1-qotmddnjs@ajou.ac.kr Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-04ipv6: Replace &nd_tbl with nd_table(net).Kuniyuki Iwashima
We will allocate per-netns neigh_table in net->neigh_tables[]. Let's replace &nd_tbl with nd_table(net). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-10-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-09-04ipv4: Replace &arp_tbl with arp_table(net).Kuniyuki Iwashima
We will allocate per-netns neigh_table in net->neigh_tables[]. Let's replace &arp_tbl with arp_table(net) and remove extern definition for arp_tbl. Three notes: 1. mlx5e_rep_netevent_event() and nfp_tun_neigh_event_handler() have code assuming neigh_table other than &arp_tbl and &nb_tbl, and the part is removed as it will be false once per-netns table is allocated. 2. prestera and rocker uses init_net because they set dev->netns_immutable to true. 3. mlx5e_tc_update_neigh_used_value() dereferences nhe->neigh_dev in trace_mlx5e_tc_update_neigh_used_value(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260902203722.926528-9-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-30vxlan: mdb: Fix use-after-free in vxlan_mdb_remote_src_del()Baul Lee
vxlan_mdb_is_valid_source(), which validates MDBE_ATTR_SOURCE and every MDBE_ATTR_SRC_LIST member, accepts the all-zeros address. A source list is only accepted on a (*, G) entry, whose source is the all-zeros address, and for each member of the list an (S, G) entry is derived from it by substituting the source. Entries are keyed by a plain memcmp() of struct vxlan_mdb_entry_key, so if MDBE_ATTR_SOURCE is present and holds the all-zeros address and the source list holds it as well, the derived (S, G) key is byte-identical to the (*, G) key and resolves to the same entry. Omitting MDBE_ATTR_SOURCE is not equivalent, as the key is then left with a zero address family. vxlan_mdb_remote_src_del() removes the forwarding entry of a source before freeing the source entry: vxlan_mdb_remote_src_fwd_del(vxlan, group, remote, &ent->addr); vxlan_mdb_remote_src_entry_del(ent); With the keys aliased, the first call deletes the remote of the entry that owns 'ent' instead of a separate (S, G) entry, and frees 'ent'. The second call then runs on the freed entry, and its hlist_del() reads ->pprev and ->next out of it and writes through them. Adding the (*, G) entry with NLM_F_REPLACE and no source list marks the all-zeros source for deletion and reaches this from the sweep at the end of vxlan_mdb_remote_srcs_replace(). BUG: KASAN: slab-use-after-free in __vxlan_mdb_add+0x1cd/0xd70 Read of size 8 at addr ffff888102852500 by task poc/84 __vxlan_mdb_add+0x1cd/0xd70 vxlan_mdb_add+0xc0/0x140 rtnl_mdb_add+0x157/0x2a0 rtnetlink_rcv_msg+0x207/0x5a0 Allocated by task 84: __kmalloc_cache_noprof+0x153/0x360 vxlan_mdb_remote_srcs_add+0x2eb/0x440 __vxlan_mdb_add+0x803/0xd70 Freed by task 84: kfree+0x14c/0x3b0 vxlan_mdb_remote_del+0x129/0x1a0 __vxlan_mdb_del+0x4f/0xe0 vxlan_mdb_remote_src_fwd_del.isra.0+0x162/0x1b0 __vxlan_mdb_add+0x1c5/0xd70 The MDB operations are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Reject the all-zeros address in vxlan_mdb_is_valid_source(), which covers both call sites. A (*, G) entry is expressed by omitting the source, so nothing legitimate is refused. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> Fixes: a3a48de5eade ("vxlan: mdb: Add MDB control path support") Signed-off-by: Baul Lee <baul.lee@xbow.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260826173604.90158-1-baul.lee@xbow.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-20vxlan: fix reading neigh haNikolay Aleksandrov
Currently arp/neigh_reduce read neigh ha directly which can lead to partial reads while the neigh is being updated. Use neigh_ha_snapshot to take a stable snapshot of the address similar to route_shortcircuit which already does the right thing. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Fixes: f564f45c4518 ("vxlan: add ipv6 proxy support") Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260818150756.890025-3-razor@blackwall.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in late fixes in preparation for the net-next PR. Conflicts: drivers/dpll/dpll_core.c drivers/dpll/dpll_netlink.c 33f016b23a219 ("dpll: fix NULL deref in dpll_device_ops() during teardown race") b1d0c412088e3 ("dpll: add STATE_CONNECTED_OVERRIDE pin capability") https://lore.kernel.org/aoR9YYY2P5--3x0N@sirena.org.uk https://lore.kernel.org/aoR9VmKllVGwmQn_@sirena.org.uk No adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-18vxlan: mdb: Fix use-after-free in vxlan_mdb_flush()Baul Lee
vxlan_mdb_flush() iterates over the MDB entries using hlist_for_each_entry_safe(), which only tolerates the removal of the current entry. Contrary to the comment above the loop, the removal of an entry can trigger the removal of another entry. Flushing the remotes of a (*, G) entry also removes the (S, G) entries that were created for its source list, once they are left without remotes: vxlan_mdb_remotes_flush() -> vxlan_mdb_remote_del() -> vxlan_mdb_remote_srcs_del() -> vxlan_mdb_remote_src_del() -> vxlan_mdb_remote_src_fwd_del() -> __vxlan_mdb_del() -> vxlan_mdb_entry_put() Such an entry can be located after the (*, G) entry in the list, as vxlan_mdb_entry_get() returns an existing entry without moving it to the head of the list. This order is obtained by adding the (S, G) entry before the (*, G) entry, the latter with NLM_F_REPLACE, as the addition of the source otherwise fails with -EEXIST. The (S, G) entry is then the entry saved by hlist_for_each_entry_safe() and it is freed while the (*, G) entry is processed. The next iteration calls hlist_del() on it again, writing LIST_POISON1 to LIST_POISON2 [1]. Besides device deletion, the flush is also reachable from RTM_DELMDB with NLM_F_BULK. Fix by re-reading the next entry after the remotes were flushed. The current entry cannot be removed by this flush, as source lists can only be configured on (*, G) entries and the removed entries are (S, G) entries. It is therefore still linked and its next pointer reflects the removals. [1] BUG: KASAN: wild-memory-access in vxlan_mdb_entry_put.part.0+0x328/0x588 Write of size 8 at addr dead000000000122 by task ip/327 CPU: 3 UID: 1000 PID: 327 Comm: ip Not tainted 7.2.0-rc7 #2 PREEMPT Call trace: vxlan_mdb_entry_put.part.0+0x328/0x588 vxlan_mdb_flush+0x1d8/0x25c vxlan_mdb_fini+0x8c/0x100 vxlan_uninit+0x1c/0x7c unregister_netdevice_many_notify+0x954/0xd4c rtnl_dellink+0x210/0x530 rtnetlink_rcv_msg+0x434/0x4d0 netlink_rcv_skb+0xc4/0x204 rtnetlink_rcv+0x18/0x24 netlink_unicast+0x4b8/0x548 netlink_sendmsg+0x29c/0x560 ____sys_sendmsg+0x390/0x3ec ___sys_sendmsg+0x114/0x188 __sys_sendmsg+0xf0/0x178 __arm64_sys_sendmsg+0x48/0x60 invoke_syscall.constprop.0+0x58/0x180 el0_svc_common.constprop.0+0x74/0x140 do_el0_svc+0x30/0x40 el0_svc+0x38/0x98 el0t_64_sync_handler+0xa0/0xe4 el0t_64_sync+0x198/0x19c Fixes: a3a48de5eade ("vxlan: mdb: Add MDB control path support") Signed-off-by: Baul Lee <baul.lee@xbow.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260814153547.29567-1-baul.lee@xbow.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-17vxlan: vnifilter: enforce exact length of GROUP/GROUP6 attributesXiang Mei
The VXLAN VNI filter entry policy declares the GROUP/GROUP6 address attributes as NLA_BINARY with only a maximum length, so validate_nla() accepts a payload shorter than the address. The GROUP consumer reads it with nla_get_in_addr(), an unconditional 4-byte load, so a short attribute over-reads up to 3 bytes of uninitialised slab data, which are stored into remote_ip and echoed back via RTM_GETTUNNEL, disclosing kernel memory. Switch both entries to NLA_POLICY_EXACT_LEN() so the validator rejects any GROUP/GROUP6 that is not exactly 4 / 16 bytes; a valid address is always sent at full width. Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Reported-by: Weiming Shi <bestswngs@gmail.com> Signed-off-by: Xiang Mei <xmei5@asu.edu> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260812215341.763123-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-17vxlan: keep the last remote linked during FDB flushKyle Zeng
A non-nexthop FDB entry is expected to have at least one remote while it remains reachable through the FDB hash table. A filtered bulk flush violates this invariant when every remote matches: It unlinks the last remote in vxlan_fdb_dst_destroy() and only afterwards tells vxlan_flush() to destroy the parent FDB entry. An RCU reader can find the parent during this interval. first_remote_rcu() then applies list_entry_rcu() to the empty list head, producing an invalid remote pointer that the receive learning path can read from and write to. When a matching remote is the sole remaining remote, leave it linked and ask the caller to destroy the entire FDB entry. vxlan_fdb_destroy() keeps the remote attached while sending the deletion notification and removing the parent from the lookup structures. Fixes: c499fccb71cb ("vxlan: vxlan_core: Support FDB flushing by destination VNI") Cc: stable@vger.kernel.org Signed-off-by: Kyle Zeng <kylebot@openai.com> Co-developed-by: David Lee <david.lee@trailofbits.com> Signed-off-by: David Lee <david.lee@trailofbits.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260810144115.821654-1-david.lee@trailofbits.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-13Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.2-rc8). No conflicts. Adjacent changes: drivers/net/ethernet/wangxun/ngbe/ngbe_main.c 5f3a13e0bb5e ("net: ngbe: fix NULL pointer dereference in non-MSI-X interrupt enabling") d661abdc30c2 ("net: ngbe: correct misleading interrupt comment") drivers/net/ipvlan/ipvlan_main.c e16e960d55a4 ("ipvlan: inherit needed_headroom and needed_tailroom from phy_dev") 00a40d809207 ("ipvlan: Support per-netns netdev unregistration.") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-08-11vxlan: do not arm the ageing timer on a device that is downBaul Lee
vxlan_changelink() arms vxlan->age_timer whenever the requested ageing interval differs from the configured one: if (conf.age_interval != vxlan->cfg.age_interval) mod_timer(&vxlan->age_timer, jiffies); There is no netif_running() test, so the timer is armed even on a device that was never brought up. The only synchronous cancel in the driver is the timer_delete_sync() in vxlan_stop(), which is .ndo_stop. netif_close_many() drops devices without IFF_UP before __dev_close_many() runs, so that cancel is skipped for such a device. vxlan_setup() sets dev->needs_free_netdev = true and age_timer is a member of struct vxlan_dev, so free_netdev() releases the allocation the timer lives in while it is still queued on a timer_base. expire_timers() unlinks the entry before it loads timer->function, so the timer core writes through the freed object's list pointers: BUG: KASAN: slab-use-after-free in __run_timers+0x208/0x654 Write of size 8 at addr ffff00001adace68 by task true/192 __asan_store8+0x84/0xac __run_timers+0x208/0x654 run_timer_softirq+0x154/0x18c Allocated by task 189: alloc_netdev_mqs+0x64/0x720 rtnl_create_link+0x4ac/0x520 rtnl_newlink+0x758/0xd00 Freed by task 191: netdev_release+0x40/0x58 netdev_run_todo+0x4a4/0x8c0 rtnl_dellink+0x200/0x4e8 The rtnl operations involved are netns-scoped, so an unprivileged user can perform them in a new user and network namespace. Arming the timer on a down device never had an effect: vxlan_cleanup() returns early on !netif_running(), and vxlan_open() arms the timer for any non-zero interval once the device is brought up. Add the missing test. Discovered by XBOW, triaged by Baul Lee <baul.lee@xbow.com> Fixes: 40051c4dcad5 ("vxlan: Allow changing ageing time") Cc: stable@vger.kernel.org Signed-off-by: Baul Lee <baul.lee@xbow.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260809111829.78834-1-baul.lee@xbow.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-08-06net: vxlan: remove unused vxlan_dev_createIlya Maximets
The vport-vxlan in openvswitch was the last user and it is now gone. And we can now rename the internal function to have a better name. Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260804182049.2289754-7-i.maximets@ovn.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-07-30Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.2-rc6). No conflicts. Adjacent changes: net/ipv4/route.c dbc3791e3b24 ("net: do not send ICMP/NDISC Redirects when peer allocation fails") 7804eaa057fe ("ipv4: snapshot dst.dev in ip_rt_send_redirect() and ip_rt_get_source()") drivers/net/tun.c 23dad2d088df ("tun: no longer rely on RTNL in tun_fill_info()") c3da92af07ea ("Revert "tun/tap: add ptr_ring consume helper with netdev queue wakeup"") drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c 3bd438a58e91 ("octeontx2-af: Block VFs from clobbering special CGX PKIND state") 5ba5611ef946 ("octeontx2-af: reserve 4 PKINDs for skip-size custom use") drivers/net/wireless/ath/ath12k/core.h drivers/net/wireless/ath/ath12k/mac.c drivers/net/wireless/ath/ath12k/peer.c 469d7e6077c1 ("wifi: ath12k: resolve PENDING ML peer ID from MLO_PEER_MAP HTT event") 378e659029d5 ("wifi: ath12k: introduce host_alloc_ml_id hardware parameter") c42b27336eef ("wifi: ath12k: fix survey indexing across bands") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27vxlan: use pskb_network_may_pull() for transmit path header pullsEric Dumazet
In vxlan_xmit(), arp_reduce(), and vxlan_mdb_entry_skb_get(), pskb_may_pull() was being called to verify the availability of network layer headers (ARP, IPv6/ND, IP/IPv6 MDB keys). However, during transmit skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, len) only checks len bytes from skb->data rather than skb_network_offset(skb) + len, which can leave part of the network header in non-linear frags. Replace these remaining pskb_may_pull() calls with pskb_network_may_pull() to properly account for the MAC header offset. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Fixes: f564f45c4518 ("vxlan: add ipv6 proxy support") Fixes: 0f83e69f44bf ("vxlan: Add MDB data path support") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: stable@vger.kernel.org Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://patch.msgid.link/20260723144249.759100-6-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27vxlan: use pskb_network_may_pull() in route_shortcircuit()Eric Dumazet
route_shortcircuit() currently calls pskb_may_pull(skb, sizeof(struct iphdr)) (or ipv6hdr), which checks if bytes are available starting from skb->data. However, in vxlan_xmit(), skb->data points to the MAC header, so skb_network_offset(skb) is ETH_HLEN (14 bytes). Using pskb_may_pull(skb, 20) only checks 20 bytes from skb->data (which is 14 bytes MAC header + 6 bytes of IP header), leaving the rest of the IP header potentially un-pulled in non-linear frags. Subsequent dereferences of ip_hdr(skb)->daddr can read beyond the pulled linear buffer length. Fix this by using pskb_network_may_pull(), which adds skb_network_offset(skb) to the length check to ensure the full network header is present in the linear buffer. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20260723144249.759100-5-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27vxlan: use neigh_ha_snapshot() in route_shortcircuit()Eric Dumazet
The neighbour hardware address n->ha can be updated asynchronously by the neighbour subsystem, protected by n->ha_lock seqlock. Reading n->ha without holding the seqlock loop can lead to torn reads or reading a partially updated MAC address. Use neigh_ha_snapshot() in route_shortcircuit() to safely copy n->ha under read_seqbegin()/read_seqretry() lock protection before using it. Note that arp_reduce() and neigh_reduce() seem to have the same issue left for future patches. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20260723144249.759100-4-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27vxlan: unclone skb head before modifying eth header in route_shortcircuit()Eric Dumazet
When route_shortcircuit() performs L3 short-circuit routing, it modifies the Ethernet header of the skb in-place: memcpy(eth_hdr(skb)->h_source, eth_hdr(skb)->h_dest, dev->addr_len); memcpy(eth_hdr(skb)->h_dest, n->ha, dev->addr_len); If the incoming skb is cloned (for example by packet sockets, tcpdump, or dev_queue_xmit), modifying the Ethernet header without uncloning can corrupt the packet header for other readers holding a reference to the cloned skb. Ensure the skb header is writable and unshared by calling skb_cow_head(skb, 0) prior to updating the Ethernet header. If skb_cow_head() fails, abort short-circuiting and return false to allow standard packet processing fallback. Fixes: e4f67addf158 ("add DOVE extensions for VXLAN") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20260723144249.759100-3-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-27vxlan: re-fetch eth header after route_shortcircuit()Eric Dumazet
Before route_shortcircuit(), the eth header pointer is cached from eth_hdr(skb). Inside route_shortcircuit(), pskb_may_pull() can be called, which may reallocate skb->head. In this case, returning to vxlan_xmit() leaves the cached eth pointer pointing to freed memory, leading to a use-after-free when dereferencing eth->h_dest. Fix this by updating eth = eth_hdr(skb) after calling route_shortcircuit(). Fixes: ae8840825605 ("VXLAN: Allow L2 redirection with L3 switching") Cc: stable@vger.kernel.org Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev> Link: https://patch.msgid.link/20260723144249.759100-2-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.2-rc5). Conflicts: drivers/net/amt.c 3656a79f94c47 ("amt: re-read skb header pointers after every pull") 586c4dcf28eb6 ("amt: no longer rely on RTNL in amt_fill_info()") https://lore.kernel.org/amIaJr3aOQNS_Fvl@sirena.org.uk Adjacent changes: drivers/net/geneve.c 8efb8f8bbb35 ("geneve: require CAP_NET_ADMIN in the device netns for changelink") 0ba269933f73 ("geneve: convert config to RCU-protected pointer") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-23vxlan: require CAP_NET_ADMIN in the device netns for changelinkDoruk Tan Ozturk
A tunnel changelink() operates on at most two netns, dev_net(dev) and the sticky underlay netns vxlan->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 vxlan->net can rewrite a vxlan device whose underlay lives in vxlan->net. vxlan_changelink() validates and applies the new configuration against vxlan->net (vxlan_config_validate(vxlan->net, ...)) and can reopen the underlay socket in that netns, so the same reasoning as the tunnel changelink series applies here. Gate vxlan_changelink() with rtnl_dev_link_net_capable(), at the top of the op before any attribute is parsed, matching ipgre_changelink() and the rest of the "require CAP_NET_ADMIN in the device netns for changelink" series. Found by 0sec automated security-research tooling (https://0sec.ai). Fixes: 8bcdc4f3a20b ("vxlan: add changelink support") Cc: stable@vger.kernel.org Signed-off-by: Doruk Tan Ozturk <doruk@0sec.ai> Reviewed-by: Fernando Fernandez Mancera <fmancera@suse.de> Link: https://patch.msgid.link/20260716203500.70573-2-doruk@0sec.ai Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-22vxlan: mdb: Fix source list corruption on a failed replaceJames Raphael Tiovalen
When replacing the source list of an MDB remote entry, all existing sources are first marked for deletion and vxlan_mdb_remote_srcs_add() is then called to add the new source list. Sources present in the new list have their deletion mark cleared, and any sources left marked afterwards are removed. If vxlan_mdb_remote_srcs_add() fails partway through, its error path deletes all entries on the remote's source list. That rollback is only correct for its other caller, vxlan_mdb_remote_add(), where the remote was just allocated and the list contains solely entries added during the call. On the replace path the list also holds pre-existing sources, so a failed replace tears them down together with their (S, G) forwarding entries instead of leaving the entry unchanged. This is reachable from an existing (*, G) remote. An EXCLUDE filter that loses sources starts forwarding traffic that should be blocked, while an INCLUDE filter that loses sources drops traffic that should be forwarded. Mark entries created during the current pass with a new VXLAN_SGRP_F_NEW flag. On failure, delete only those entries and clear the deletion mark on the pre-existing ones, so a failed replace leaves the source list untouched. Retain the flag until the whole operation succeeds and then clear it. Also stop vxlan_mdb_remote_src_add() from deleting a pre-existing entry it only looked up when adding that entry's forwarding entry fails. Fixes: a3a48de5eade ("vxlan: mdb: Add MDB control path support") Cc: stable@vger.kernel.org Signed-off-by: James Raphael Tiovalen <jamestiotio@gmail.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Antoine Tenart <atenart@kernel.org> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20260720160428.249356-1-jamestiotio@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-07-22vxlan: Enable BIG TCP packetsAlice Mikityanska
In Cilium we do support BIG TCP, but so far the latter has only been enabled for direct routing use-cases. A lot of users rely on Cilium with vxlan/geneve tunneling though. The underlying kernel infra for tunneling has not been supporting BIG TCP up to this point. Given we do now, bump tso_max_size for vxlan netdevs up to GSO_MAX_SIZE to allow the admin to use BIG TCP with vxlan tunnels. BIG TCP on vxlan disabled: Standard MTU: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 30.00 34440.00 8k MTU: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 262144 32768 32768 30.00 55684.26 BIG TCP on vxlan enabled: Standard MTU: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 30.00 39564.78 8k MTU: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 262144 32768 32768 30.00 61466.47 When tunnel offloads are not enabled/exposed and we fully need to rely on SW-based segmentation on transmit (e.g. in case of Azure) then the more aggressive batching also has a visible effect. Below example was on the same setup as with above benchmarks but with HW support disabled: # ethtool -k enp10s0f0np0 | grep udp tx-udp_tnl-segmentation: off tx-udp_tnl-csum-segmentation: off tx-udp-segmentation: off rx-udp_tunnel-port-offload: off rx-udp-gro-forwarding: off Before: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 60.00 21820.82 After: # netperf -H 10.1.0.2 -t TCP_STREAM -l60 MIGRATED TCP STREAM TEST from 0.0.0.0 (0.0.0.0) port 0 AF_INET to 10.1.0.2 () port 0 AF_INET : demo Recv Send Send Socket Socket Message Elapsed Size Size Size Time Throughput bytes bytes bytes secs. 10^6bits/sec 131072 16384 16384 60.00 29390.78 Example receive side: swapper 0 [002] 4712.645070: net:netif_receive_skb: dev=enp10s0f0np0 skbaddr=0xffff8f3b086e0200 len=129542 ffffffff8cfe3aaa __netif_receive_skb_core.constprop.0+0x6ca ([kernel.kallsyms]) ffffffff8cfe3aaa __netif_receive_skb_core.constprop.0+0x6ca ([kernel.kallsyms]) ffffffff8cfe47dd __netif_receive_skb_list_core+0xed ([kernel.kallsyms]) ffffffff8cfe4e52 netif_receive_skb_list_internal+0x1d2 ([kernel.kallsyms]) ffffffff8d0210d8 gro_complete.constprop.0+0x108 ([kernel.kallsyms]) ffffffff8d021724 dev_gro_receive+0x4e4 ([kernel.kallsyms]) ffffffff8d021a99 gro_receive_skb+0x89 ([kernel.kallsyms]) ffffffffc06edb71 mlx5e_handle_rx_cqe_mpwrq+0x131 ([kernel.kallsyms]) ffffffffc06ee38a mlx5e_poll_rx_cq+0x9a ([kernel.kallsyms]) ffffffffc06ef2c7 mlx5e_napi_poll+0x107 ([kernel.kallsyms]) ffffffff8cfe586d __napi_poll+0x2d ([kernel.kallsyms]) ffffffff8cfe5f8d net_rx_action+0x20d ([kernel.kallsyms]) ffffffff8c35d252 handle_softirqs+0xe2 ([kernel.kallsyms]) ffffffff8c35d556 __irq_exit_rcu+0xd6 ([kernel.kallsyms]) ffffffff8c35d81e irq_exit_rcu+0xe ([kernel.kallsyms]) ffffffff8d2602b8 common_interrupt+0x98 ([kernel.kallsyms]) ffffffff8c000da7 asm_common_interrupt+0x27 ([kernel.kallsyms]) ffffffff8d2645c5 cpuidle_enter_state+0xd5 ([kernel.kallsyms]) ffffffff8cf6358e cpuidle_enter+0x2e ([kernel.kallsyms]) ffffffff8c3ba932 call_cpuidle+0x22 ([kernel.kallsyms]) ffffffff8c3bfb5e do_idle+0x1ce ([kernel.kallsyms]) ffffffff8c3bfd79 cpu_startup_entry+0x29 ([kernel.kallsyms]) ffffffff8c30a6c2 start_secondary+0x112 ([kernel.kallsyms]) ffffffff8c2c142d common_startup_64+0x13e ([kernel.kallsyms]) Example transmit side: swapper 0 [005] 4768.021375: net:net_dev_xmit: dev=enp10s0f0np0 skbaddr=0xffff8af32ebe1200 len=129556 rc=0 ffffffffa75e19c3 dev_hard_start_xmit+0x173 ([kernel.kallsyms]) ffffffffa75e19c3 dev_hard_start_xmit+0x173 ([kernel.kallsyms]) ffffffffa7653823 sch_direct_xmit+0x143 ([kernel.kallsyms]) ffffffffa75e2780 __dev_queue_xmit+0xc70 ([kernel.kallsyms]) ffffffffa76a1205 ip_finish_output2+0x265 ([kernel.kallsyms]) ffffffffa76a1577 __ip_finish_output+0x87 ([kernel.kallsyms]) ffffffffa76a165b ip_finish_output+0x2b ([kernel.kallsyms]) ffffffffa76a179e ip_output+0x5e ([kernel.kallsyms]) ffffffffa76a19d5 ip_local_out+0x35 ([kernel.kallsyms]) ffffffffa770d0e5 iptunnel_xmit+0x185 ([kernel.kallsyms]) ffffffffc179634e nf_nat_used_tuple_new.cold+0x1129 ([kernel.kallsyms]) ffffffffc17a7301 vxlan_xmit_one+0xc21 ([kernel.kallsyms]) ffffffffc17a80a2 vxlan_xmit+0x4a2 ([kernel.kallsyms]) ffffffffa75e18af dev_hard_start_xmit+0x5f ([kernel.kallsyms]) ffffffffa75e1d3f __dev_queue_xmit+0x22f ([kernel.kallsyms]) ffffffffa76a1205 ip_finish_output2+0x265 ([kernel.kallsyms]) ffffffffa76a1577 __ip_finish_output+0x87 ([kernel.kallsyms]) ffffffffa76a165b ip_finish_output+0x2b ([kernel.kallsyms]) ffffffffa76a179e ip_output+0x5e ([kernel.kallsyms]) ffffffffa76a1de2 __ip_queue_xmit+0x1b2 ([kernel.kallsyms]) ffffffffa76a2135 ip_queue_xmit+0x15 ([kernel.kallsyms]) ffffffffa76c70a2 __tcp_transmit_skb+0x522 ([kernel.kallsyms]) ffffffffa76c931a tcp_write_xmit+0x65a ([kernel.kallsyms]) ffffffffa76cb42e tcp_tsq_write+0x5e ([kernel.kallsyms]) ffffffffa76cb7ef tcp_tasklet_func+0x10f ([kernel.kallsyms]) ffffffffa695d9f7 tasklet_action_common+0x107 ([kernel.kallsyms]) ffffffffa695db99 tasklet_action+0x29 ([kernel.kallsyms]) ffffffffa695d252 handle_softirqs+0xe2 ([kernel.kallsyms]) ffffffffa695d556 __irq_exit_rcu+0xd6 ([kernel.kallsyms]) ffffffffa695d81e irq_exit_rcu+0xe ([kernel.kallsyms]) ffffffffa78602b8 common_interrupt+0x98 ([kernel.kallsyms]) ffffffffa6600da7 asm_common_interrupt+0x27 ([kernel.kallsyms]) ffffffffa78645c5 cpuidle_enter_state+0xd5 ([kernel.kallsyms]) ffffffffa756358e cpuidle_enter+0x2e ([kernel.kallsyms]) ffffffffa69ba932 call_cpuidle+0x22 ([kernel.kallsyms]) ffffffffa69bfb5e do_idle+0x1ce ([kernel.kallsyms]) ffffffffa69bfd79 cpu_startup_entry+0x29 ([kernel.kallsyms]) ffffffffa690a6c2 start_secondary+0x112 ([kernel.kallsyms]) ffffffffa68c142d common_startup_64+0x13e ([kernel.kallsyms]) Signed-off-by: Alice Mikityanska <alice@isovalent.com> Co-developed-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Cc: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Willem de Bruijn <willemb@google.com> Link: https://patch.msgid.link/20260710134242.216538-8-alice.kernel@fastmail.im Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.1-rc7). Silent conflicts: net/wireless/nl80211.c cb9959ab5f99 ("wifi: cfg80211: enforce HE/EHT cap/oper consistency") a384ae969902 ("wifi: cfg80211: move AP HT/VHT/... operation to beacon info") https://lore.kernel.org/aiGJDaHV4UlCexIQ@sirena.org.uk Conflicts: drivers/net/wireless/intel/iwlwifi/mld/ap.c a342c99cb70d ("wifi: iwlwifi: mld: honor BSS_CHANGED_BEACON_ENABLED") 9bf1b409afc7 ("wifi: iwlwifi: mld: send tx power constraints before link activation") https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk drivers/net/wireless/intel/iwlwifi/pcie/drv.c 093305d801fa ("wifi: iwlwifi: pcie: simplify the resume flow if fast resume is not used") e2323929a68a ("wifi: iwlwifi: pcie: add debug print for resume flow if powered off") https://lore.kernel.org/ah2bfedhV45ZxMO8@sirena.org.uk Adjacent changes: drivers/net/ethernet/airoha/airoha_eth.c b38cae85d1c4 ("net: airoha: Fix use-after-free in metadata dst teardown") ec6c391bcca7 ("net: airoha: Introduce airoha_gdm_dev struct") drivers/net/ethernet/microchip/lan743x_main.c 8173d22b211f ("net: lan743x: permit VLAN-tagged packets up to configured MTU") e3c6508a46f5 ("net: lan743x: avoid netdev-based logging before netdev registration") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04vxlan: vnifilter: fix spurious notification on VNI updateAndy Roulin
When a VNI is re-added with the same attributes (e.g. same group or no group), vxlan_vni_update() sends a spurious RTM_NEWTUNNEL notification even though nothing changed. The bug is that 'if (changed)' tests whether the pointer is non-NULL, not the bool value it points to. Since every caller passes a valid pointer, the condition is always true and the notification fires unconditionally. Fix by dereferencing the pointer: 'if (*changed)'. Reproducer: # ip link add vxlan100 type vxlan dstport 4789 local 10.0.0.1 \ nolearning external vnifilter # ip link set vxlan100 up # bridge monitor vni & # bridge vni add vni 1000 dev vxlan100 # bridge vni add vni 1000 dev vxlan100 # spurious notification Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Signed-off-by: Andy Roulin <aroulin@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Link: https://patch.msgid.link/20260602185138.253265-3-aroulin@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-06-04vxlan: vnifilter: send notification on VNI addAndy Roulin
When a new VNI is added to a vxlan device with vnifilter enabled, no RTM_NEWTUNNEL notification is sent to userspace. This means 'bridge monitor vni' never shows VNI add events, even though VNI delete events are reported correctly. The bug is in vxlan_vni_add(), where the notification is guarded by 'if (changed)'. The 'changed' flag is set by vxlan_vni_update_group() only when the multicast group or remote IP is modified, but for a new VNI added without a group (e.g. in L3 VxLAN interface scenarios), the function returns early without setting changed=true. Since this is a new VNI, the notification should be sent unconditionally. The notification is not guarded by the return value of vxlan_vni_update_group() because, at this point, the VNI has already been inserted into the hash table and list with no rollback on error. The VNI will be visible in 'bridge vni show' regardless, so userspace should be informed. This is consistent with vxlan_vni_del() which also notifies unconditionally. The 'if (changed)' guard remains correct in vxlan_vni_update(), which handles the case where a VNI already exists and is being re-added -- there, we only want to notify if the group/remote actually changed. Reproducer: # ip link add vxlan100 type vxlan dstport 4789 local 10.0.0.1 \ nolearning external vnifilter # ip link set vxlan100 up # bridge monitor vni & # bridge vni add vni 1000 dev vxlan100 # no notification # bridge vni delete vni 1000 dev vxlan100 # notification received Fixes: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Reported-by: Chirag Shah <chirag@nvidia.com> Signed-off-by: Andy Roulin <aroulin@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Link: https://patch.msgid.link/20260602185138.253265-2-aroulin@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.1-rc6). Conflicts: drivers/net/phy/air_en8811h.c d895767c33781 ("net: phy: air_en8811h: add AN8811HB MCU assert/deassert support") dddfadd75197e ("net: phy: Add Airoha phy library for shared code") 5226bb6634cdf ("net: phy: air_phy_lib: Factorize BuckPBus register accessors") e08f0ea6daf2e ("net: phy: Rename Airoha common BuckPBus register accessors") net/sched/sch_netem.c a2f6ed7b4873 ("net/sched: netem: add per-impairment extended statistics") 9552b11e3eda ("net/sched: fix packet loop on netem when duplicate is on") Adjacent changes: drivers/dpll/zl3073x/core.c c1224569cef0 ("dpll: zl3073x: make frequency monitor a per-device attribute") 54e65df8cf18 ("dpll: zl3073x: report FFO as DPLL vs input reference offset") net/iucv/af_iucv.c 347fdd4df85f ("af_iucv: convert to getsockopt_iter") 3589d20a666c ("net/iucv: fix locking in .getsockopt") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-26vxlan: do not reuse cached ip_hdr() value after skb_tunnel_check_pmtu()Eric Dumazet
skb_tunnel_check_pmtu() can change skb->head. Reusing old_iph afer skb_tunnel_check_pmtu() can cause an UAF. Use instead ip_hdr(skb) as done in drivers/net/bareudp.c and drivers/net/geneve.c. Found by Sashiko. Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Stefano Brivio <sbrivio@redhat.com> Link: https://patch.msgid.link/20260525203642.2389723-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-20vxlan: Remove synchronize_net() in vxlan_sock_release().Kuniyuki Iwashima
Initially, a dedicated workqueue was used to defer calling udp_tunnel_sock_release(vxlan_sock->sock) and kfree(vxlan_sock). Later, commit 0412bd931f5f ("vxlan: synchronously and race-free destruction of vxlan sockets") removed the workqueue and instead invoked these two functions immediately after synchronize_net(). This was intended to prevent UAF of the UDP socket in the fast path. ( Note that the "nondeterministic behaviour" mentioned in that commit was not addressed, as another thread not waiting RCU gp still sees the same behaviour. ) However, a week prior to that change, commit ca065d0cf80f ("udp: no longer use SLAB_DESTROY_BY_RCU") had already moved UDP socket freeing to after the RCU grace period. This made the synchronize_net() in vxlan_sock_release() completely redundant. Since vxlan_sock now uses kfree_rcu() and is invoked after udp_tunnel_sock_release(), vxlan_sock is guaranteed to be freed either at the same time or after the UDP socket is released, following the RCU grace period. Let's remove the redundant synchronize_net() in vxlan_sock_release(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260518050726.318824-2-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-05vxlan: Free vxlan_sock with kfree_rcu().Kuniyuki Iwashima
We will remove synchronize_rcu() in udp_tunnel_sock_release(). We must ensure that vxlan_sock is freed after inflight RX fast path. Let's free vxlan_sock with kfree_rcu(). Note that vxlan_sock.vni_list[] is 8K and struct rcu_head must be placed before it. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260502031401.3557229-9-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-05vxlan: Store struct sock in struct vxlan_sock.Kuniyuki Iwashima
Commit 3cf7203ca620 ("net/tunnel: wait until all sk_user_data reader finish before releasing the sock") added synchronize_rcu() in udp_tunnel_sock_release(). This was intended to protect the fast path of a dying vxlan device from dereferencing vxlan_sock->sock->sk after sock_orphan() has set sock->sk to NULL. However, vxlan does not need to access struct socket itself in the fast path; it only reads struct sock, and struct socket is only used for tunnel setup and teardown. Let's store struct sock directly in struct vxlan_sock. In the next patch, we will free vxlan_sock with kfree_rcu(), then vxlan no longer needs synchronize_rcu() in udp_tunnel_sock_release(). Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260502031401.3557229-8-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-05vxlan: Fix potential null-ptr-deref in vxlan_gro_prepare_receive().Kuniyuki Iwashima
udp_tunnel_sock_release() could set sk->sk_user_data to NULL while vxlan_gro_prepare_receive() is running. Let's check if rcu_dereference_sk_user_data() is NULL after skb_gro_remcsum_init(). Fixes: 5602c48cf875 ("vxlan: change vxlan to use UDP socket GRO") Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260502031401.3557229-7-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-05-05udp_tunnel: Pass struct sock to udp_tunnel_notify_{add,del}_rx_port().Kuniyuki Iwashima
None of the udp_tunnel users need struct socket in their fast paths; it is only used for tunnel setup / teardown. Even udp_tunnel_notify_{add,del}_rx_port() do not need struct socket. Let's change udp_tunnel_notify_{add,del}_rx_port() to take struct sock instead of struct socket. Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260502031401.3557229-6-kuniyu@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>