kernel/linux.git/net/core/rtnetlink.c, branch v6.18.21

rtnetlink: fix leak of SRCU struct in rtnl_link_register

2026-04-02T11:23:08+00:00

[ Upstream commit 09474055f2619be9445ba4245e4013741ed01a5e ] Commit 6b57ff21a310 ("rtnetlink: Protect link_ops by mutex.") swapped the EEXIST check with the init_srcu_struct, but didn't add cleanup of the SRCU struct we just allocated in case of error. Fixes: 6b57ff21a310 ("rtnetlink: Protect link_ops by mutex.") Signed-off-by: Sabrina Dubroca Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/e77fe499f9a58c547b33b5212b3596dad417cec6.1774025341.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rtnetlink: count IFLA_INFO_SLAVE_KIND in if_nlmsg_size

2026-04-02T11:23:05+00:00

[ Upstream commit ee00a12593ffb69db4dd1a1c00ecb0253376874a ] rtnl_link_get_slave_info_data_size counts IFLA_INFO_SLAVE_DATA, but rtnl_link_slave_info_fill adds both IFLA_INFO_SLAVE_DATA and IFLA_INFO_SLAVE_KIND. Fixes: ba7d49b1f0f8 ("rtnetlink: provide api for getting and setting slave info") Reviewed-by: Jiri Pirko Signed-off-by: Sabrina Dubroca Link: https://patch.msgid.link/049843b532e23cde7ddba263c0bbe35ba6f0d26d.1773919462.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rtnetlink: count IFLA_PARENT_DEV_{NAME,BUS_NAME} in if_nlmsg_size

2026-04-02T11:23:05+00:00

[ Upstream commit 52501989c76206462d9b11a8485beef40ef41821 ] Commit 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME") added those attributes to rtnl_fill_ifinfo, but forgot to extend if_nlmsg_size. Fixes: 00e77ed8e64d ("rtnetlink: add IFLA_PARENT_[DEV|DEV_BUS]_NAME") Signed-off-by: Sabrina Dubroca Link: https://patch.msgid.link/0b849da95562af45487080528d60f578636aba5c.1773919462.git.sd@queasysnail.net Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

rtnetlink: Allow deleting FDB entries in user namespace

2025-10-16T23:09:56+00:00

Creating FDB entries is possible from a non-initial user namespace when having CAP_NET_ADMIN, yet, when deleting FDB entries, processes receive an EPERM because the capability is always checked against the initial user namespace. This restricts the FDB management from unprivileged containers. Drop the netlink_capable check in rtnl_fdb_del as it was originally dropped in c5c351088ae7 and reintroduced in 1690be63a27b without intention. This patch was tested using a container on GyroidOS, where it was possible to delete FDB entries from an unprivileged user namespace and private network namespace. Fixes: 1690be63a27b ("bridge: Add vlan support to static neighbors") Reviewed-by: Michael Weiß Tested-by: Harshal Gohel Signed-off-by: Johannes Wiesböck Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20251015201548.319871-1-johannes.wiesboeck@aisec.fraunhofer.de Signed-off-by: Jakub Kicinski

net: rtnetlink: fix typo in rtnl_unregister_all() comment

2025-09-30T01:31:08+00:00

Corrected "rtnl_unregster()" -> "rtnl_unregister()" in the documentation comment of "rtnl_unregister_all()" Signed-off-by: Alok Tiwari Reviewed-by: Simon Horman Link: https://patch.msgid.link/20250929085418.49200-1-alok.a.tiwari@oracle.com Signed-off-by: Jakub Kicinski

rtnetlink: add needed_{head,tail}room attributes

2025-09-20T00:21:55+00:00

Various network interface types make use of needed_{head,tail}room values to efficiently reserve buffer space for additional encapsulation headers, such as VXLAN, Geneve, IPSec, etc. However, it is not currently possible to query these values in a generic way. Introduce ability to query the needed_{head,tail}room values of a network device via rtnetlink, such that applications that may wish to use these values can do so. For example, Cilium agent iterates over present devices based on user config (direct routing, vxlan, geneve, wireguard etc.) and in future will configure netkit in order to expose the needed_{head,tail}room into K8s pods. See b9ed315d3c4c ("netkit: Allow for configuring needed_{head,tail}room"). Suggested-by: Daniel Borkmann Signed-off-by: Alasdair McWilliam Reviewed-by: Daniel Borkmann Link: https://patch.msgid.link/20250917095543.14039-1-alasdair@mcwilliam.dev Signed-off-by: Jakub Kicinski

net: s/dev_get_flags/netif_get_flags/

2025-07-19T00:27:47+00:00

Commit cc34acd577f1 ("docs: net: document new locking reality") introduced netif_ vs dev_ function semantics: the former expects locked netdev, the latter takes care of the locking. We don't strictly follow this semantics on either side, but there are more dev_xxx handlers now that don't fit. Rename them to netif_xxx where appropriate. Signed-off-by: Stanislav Fomichev Link: https://patch.msgid.link/20250717172333.1288349-6-sdf@fomichev.me Signed-off-by: Jakub Kicinski

net: s/dev_get_port_parent_id/netif_get_port_parent_id/

2025-07-19T00:27:46+00:00

net: dst: annotate data-races around dst->lastuse

2025-07-02T21:32:29+00:00

(dst_entry)->lastuse is read and written locklessly, add corresponding annotations. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-4-edumazet@google.com Signed-off-by: Jakub Kicinski

net: prevent a NULL deref in rtnl_create_link()

2025-06-05T15:03:00+00:00

At the time rtnl_create_link() is running, dev->netdev_ops is NULL, we must not use netdev_lock_ops() or risk a NULL deref if CONFIG_NET_SHAPER is defined. Use netif_set_group() instead of dev_set_group(). RIP: 0010:netdev_need_ops_lock include/net/netdev_lock.h:33 [inline] RIP: 0010:netdev_lock_ops include/net/netdev_lock.h:41 [inline] RIP: 0010:dev_set_group+0xc0/0x230 net/core/dev_api.c:82 Call Trace: rtnl_create_link+0x748/0xd10 net/core/rtnetlink.c:3674 rtnl_newlink_create+0x25c/0xb00 net/core/rtnetlink.c:3813 __rtnl_newlink net/core/rtnetlink.c:3940 [inline] rtnl_newlink+0x16d6/0x1c70 net/core/rtnetlink.c:4055 rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6944 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x75b/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] Reported-by: syzbot+9fc858ba0312b42b577e@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6840265f.a00a0220.d4325.0009.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Fixes: 7e4d784f5810 ("net: hold netdev instance lock during rtnetlink operations") Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250604105815.1516973-1-edumazet@google.com Signed-off-by: Jakub Kicinski