linux-toradex.git/drivers/net/geneve.c, branch v6.17-rc1 Linux kernel for Apalis and Colibri modules geneve: rely on rtnl lock in geneve_offload_rx_ports 2025-06-19T01:53:51+00:00 Stanislav Fomichev stfomichev@gmail.com 2025-06-16T16:21:12+00:00 3e14960f3bd2a9c7d631f2517f0f249d74bfa892 udp_tunnel_push_rx_port will grab mutex in the next patch so we can't use rcu. geneve_offload_rx_ports is called from geneve_netdevice_event for NETDEV_UDP_TUNNEL_PUSH_INFO and NETDEV_UDP_TUNNEL_DROP_INFO which both have ASSERT_RTNL. Entries are added to and removed from the sock_list under rtnl lock as well (when adding or removing a tunneling device). Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/20250616162117.287806-2-stfomichev@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
udp_tunnel_push_rx_port will grab mutex in the next patch so
we can't use rcu. geneve_offload_rx_ports is called
from geneve_netdevice_event for NETDEV_UDP_TUNNEL_PUSH_INFO and
NETDEV_UDP_TUNNEL_DROP_INFO which both have ASSERT_RTNL.
Entries are added to and removed from the sock_list under rtnl
lock as well (when adding or removing a tunneling device).

Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250616162117.287806-2-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: ipv6: Add a flags argument to ip6tunnel_xmit(), udp_tunnel6_xmit_skb() 2025-06-18T01:18:45+00:00 Petr Machata petrm@nvidia.com 2025-06-16T22:44:14+00:00 f78c75d84fe83898f0a00658f593d4f17b38cbc6 ip6tunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IP6CB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel6_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IPv6 multicast routing. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Link: https://patch.msgid.link/acb4f9f3e40c3a931236c3af08a720b017fbfbfb.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
ip6tunnel_xmit() erases the contents of the SKB control block. In order to
be able to set particular IP6CB flags on the SKB, add a corresponding
parameter, and propagate it to udp_tunnel6_xmit_skb() as well.

In one of the following patches, VXLAN driver will use this facility to
mark packets as subject to IPv6 multicast routing.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/acb4f9f3e40c3a931236c3af08a720b017fbfbfb.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: ipv4: Add a flags argument to iptunnel_xmit(), udp_tunnel_xmit_skb() 2025-06-18T01:18:44+00:00 Petr Machata petrm@nvidia.com 2025-06-16T22:44:09+00:00 e3411e326fa48c9be09ba449330352ba698db698 iptunnel_xmit() erases the contents of the SKB control block. In order to be able to set particular IPCB flags on the SKB, add a corresponding parameter, and propagate it to udp_tunnel_xmit_skb() as well. In one of the following patches, VXLAN driver will use this facility to mark packets as subject to IP multicast routing. Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Acked-by: Antonio Quartulli <antonio@openvpn.net> Link: https://patch.msgid.link/89c9daf9f2dc088b6b92ccebcc929f51742de91f.1750113335.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
iptunnel_xmit() erases the contents of the SKB control block. In order to
be able to set particular IPCB flags on the SKB, add a corresponding
parameter, and propagate it to udp_tunnel_xmit_skb() as well.

In one of the following patches, VXLAN driver will use this facility to
mark packets as subject to IP multicast routing.

Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Acked-by: Antonio Quartulli <antonio@openvpn.net>
Link: https://patch.msgid.link/89c9daf9f2dc088b6b92ccebcc929f51742de91f.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
geneve: Convert geneve_exit_batch_rtnl() to ->exit_rtnl(). 2025-04-15T00:08:44+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2025-04-11T20:52:42+00:00 4e53b32d74f052458309a10867e642a8aeafd2f5 geneve_exit_batch_rtnl() iterates the dying netns list and performs the same operation for each. Let's use ->exit_rtnl(). Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Reviewed-by: Sabrina Dubroca <sd@queasysnail.net> Link: https://patch.msgid.link/20250411205258.63164-14-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
geneve_exit_batch_rtnl() iterates the dying netns list and
performs the same operation for each.

Let's use ->exit_rtnl().

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20250411205258.63164-14-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: move misc netdev_lock flavors to a separate header 2025-03-08T17:06:50+00:00 Jakub Kicinski kuba@kernel.org 2025-03-07T18:30:06+00:00 8ef890df4031121a94407c84659125cbccd3fdbe Move the more esoteric helpers for netdev instance lock to a dedicated header. This avoids growing netdevice.h to infinity and makes rebuilding the kernel much faster (after touching the header with the helpers). The main netdev_lock() / netdev_unlock() functions are used in static inlines in netdevice.h and will probably be used most commonly, so keep them in netdevice.h. Acked-by: Stanislav Fomichev <sdf@fomichev.me> Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Move the more esoteric helpers for netdev instance lock to
a dedicated header. This avoids growing netdevice.h to infinity
and makes rebuilding the kernel much faster (after touching
the header with the helpers).

The main netdev_lock() / netdev_unlock() functions are used
in static inlines in netdevice.h and will probably be used
most commonly, so keep them in netdevice.h.

Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
geneve: Allow users to specify source port range 2025-02-28T00:54:54+00:00 Daniel Borkmann daniel@iogearbox.net 2025-02-26T18:20:29+00:00 e1f95b1992b8cc31e37505787806918b0447909b Recently, in case of Cilium, we run into users on Azure who require to use tunneling for east/west traffic due to hitting IPAM API limits for Kubernetes Pods if they would have gone with publicly routable IPs for Pods. In case of tunneling, Cilium supports the option of vxlan or geneve. In order to RSS spread flows among remote CPUs both derive a source port hash via udp_flow_src_port() which takes the inner packet's skb->hash into account. For clusters with many nodes, this can then hit a new limitation [0]: Today, the Azure networking stack supports 1M total flows (500k inbound and 500k outbound) for a VM. [...] Once this limit is hit, other connections are dropped. [...] Each flow is distinguished by a 5-tuple (protocol, local IP address, remote IP address, local port, and remote port) information. [...] For vxlan and geneve, this can create a massive amount of UDP flows which then run into the limits if stale flows are not evicted fast enough. One option to mitigate this for vxlan is to narrow the source port range via IFLA_VXLAN_PORT_RANGE while still being able to benefit from RSS. However, geneve currently does not have this option and it spreads traffic across the full source port range of [1, USHRT_MAX]. To overcome this limitation also for geneve, add an equivalent IFLA_GENEVE_PORT_RANGE setting for users. Note that struct geneve_config before/after still remains at 2 cachelines on x86-64. The low/high members of struct ifla_geneve_port_range (which is uapi exposed) are of type __be16. While they would be perfectly fine to be of __u16 type, the consensus was that it would be good to be consistent with the existing struct ifla_vxlan_port_range from a uapi consumer PoV. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Link: https://learn.microsoft.com/en-us/azure/virtual-network/virtual-machine-network-throughput [0] Link: https://patch.msgid.link/20250226182030.89440-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Recently, in case of Cilium, we run into users on Azure who require to use
tunneling for east/west traffic due to hitting IPAM API limits for Kubernetes
Pods if they would have gone with publicly routable IPs for Pods. In case
of tunneling, Cilium supports the option of vxlan or geneve. In order to
RSS spread flows among remote CPUs both derive a source port hash via
udp_flow_src_port() which takes the inner packet's skb->hash into account.
For clusters with many nodes, this can then hit a new limitation [0]: Today,
the Azure networking stack supports 1M total flows (500k inbound and 500k
outbound) for a VM. [...] Once this limit is hit, other connections are
dropped. [...] Each flow is distinguished by a 5-tuple (protocol, local IP
address, remote IP address, local port, and remote port) information. [...]

For vxlan and geneve, this can create a massive amount of UDP flows which
then run into the limits if stale flows are not evicted fast enough. One
option to mitigate this for vxlan is to narrow the source port range via
IFLA_VXLAN_PORT_RANGE while still being able to benefit from RSS. However,
geneve currently does not have this option and it spreads traffic across
the full source port range of [1, USHRT_MAX]. To overcome this limitation
also for geneve, add an equivalent IFLA_GENEVE_PORT_RANGE setting for users.

Note that struct geneve_config before/after still remains at 2 cachelines
on x86-64. The low/high members of struct ifla_geneve_port_range (which is
uapi exposed) are of type __be16. While they would be perfectly fine to be
of __u16 type, the consensus was that it would be good to be consistent
with the existing struct ifla_vxlan_port_range from a uapi consumer PoV.

Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Link: https://learn.microsoft.com/en-us/azure/virtual-network/virtual-machine-network-throughput [0]
Link: https://patch.msgid.link/20250226182030.89440-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
net: Use link/peer netns in newlink() of rtnl_link_ops 2025-02-21T23:28:02+00:00 Xiao Liang shaw.leon@gmail.com 2025-02-19T12:50:29+00:00 cf517ac16ad96f3953d65ea198c0b310a1ffa14f Add two helper functions - rtnl_newlink_link_net() and rtnl_newlink_peer_net() for netns fallback logic. Peer netns falls back to link netns, and link netns falls back to source netns. Convert the use of params->net in netdevice drivers to one of the helper functions for clarity. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-4-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
Add two helper functions - rtnl_newlink_link_net() and
rtnl_newlink_peer_net() for netns fallback logic. Peer netns falls back
to link netns, and link netns falls back to source netns.

Convert the use of params->net in netdevice drivers to one of the helper
functions for clarity.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-4-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rtnetlink: Pack newlink() params into struct 2025-02-21T23:28:02+00:00 Xiao Liang shaw.leon@gmail.com 2025-02-19T12:50:28+00:00 69c7be1b903fca2835e80ec506bd1d75ce84fb4d There are 4 net namespaces involved when creating links: - source netns - where the netlink socket resides, - target netns - where to put the device being created, - link netns - netns associated with the device (backend), - peer netns - netns of peer device. Currently, two nets are passed to newlink() callback - "src_net" parameter and "dev_net" (implicitly in net_device). They are set as follows, depending on netlink attributes in the request. +------------+-------------------+---------+---------+ | peer netns | IFLA_LINK_NETNSID | src_net | dev_net | +------------+-------------------+---------+---------+ | | absent | source | target | | absent +-------------------+---------+---------+ | | present | link | link | +------------+-------------------+---------+---------+ | | absent | peer | target | | present +-------------------+---------+---------+ | | present | peer | link | +------------+-------------------+---------+---------+ When IFLA_LINK_NETNSID is present, the device is created in link netns first and then moved to target netns. This has some side effects, including extra ifindex allocation, ifname validation and link events. These could be avoided if we create it in target netns from the beginning. On the other hand, the meaning of src_net parameter is ambiguous. It varies depending on how parameters are passed. It is the effective link (or peer netns) by design, but some drivers ignore it and use dev_net instead. To provide more netns context for drivers, this patch packs existing newlink() parameters, along with the source netns, link netns and peer netns, into a struct. The old "src_net" is renamed to "net" to avoid confusion with real source netns, and will be deprecated later. The use of src_net are converted to params->net trivially. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
There are 4 net namespaces involved when creating links:

 - source netns - where the netlink socket resides,
 - target netns - where to put the device being created,
 - link netns - netns associated with the device (backend),
 - peer netns - netns of peer device.

Currently, two nets are passed to newlink() callback - "src_net"
parameter and "dev_net" (implicitly in net_device). They are set as
follows, depending on netlink attributes in the request.

 +------------+-------------------+---------+---------+
 | peer netns | IFLA_LINK_NETNSID | src_net | dev_net |
 +------------+-------------------+---------+---------+
 |            | absent            | source  | target  |
 | absent     +-------------------+---------+---------+
 |            | present           | link    | link    |
 +------------+-------------------+---------+---------+
 |            | absent            | peer    | target  |
 | present    +-------------------+---------+---------+
 |            | present           | peer    | link    |
 +------------+-------------------+---------+---------+

When IFLA_LINK_NETNSID is present, the device is created in link netns
first and then moved to target netns. This has some side effects,
including extra ifindex allocation, ifname validation and link events.
These could be avoided if we create it in target netns from
the beginning.

On the other hand, the meaning of src_net parameter is ambiguous. It
varies depending on how parameters are passed. It is the effective
link (or peer netns) by design, but some drivers ignore it and use
dev_net instead.

To provide more netns context for drivers, this patch packs existing
newlink() parameters, along with the source netns, link netns and peer
netns, into a struct. The old "src_net" is renamed to "net" to avoid
confusion with real source netns, and will be deprecated later. The use
of src_net are converted to params->net trivially.

Signed-off-by: Xiao Liang <shaw.leon@gmail.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
geneve: Suppress list corruption splat in geneve_destroy_tunnels(). 2025-02-20T02:49:29+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2025-02-17T20:37:05+00:00 62fab6eef61f245dc8797e3a6a5b890ef40e8628 As explained in the previous patch, iterating for_each_netdev() and gn->geneve_list during ->exit_batch_rtnl() could trigger ->dellink() twice for the same device. If CONFIG_DEBUG_LIST is enabled, we will see a list_del() corruption splat in the 2nd call of geneve_dellink(). Let's remove for_each_netdev() in geneve_destroy_tunnels() and delegate that part to default_device_exit_batch(). Fixes: 9593172d93b9 ("geneve: Fix use-after-free in geneve_find_dev().") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250217203705.40342-3-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
As explained in the previous patch, iterating for_each_netdev() and
gn->geneve_list during ->exit_batch_rtnl() could trigger ->dellink()
twice for the same device.

If CONFIG_DEBUG_LIST is enabled, we will see a list_del() corruption
splat in the 2nd call of geneve_dellink().

Let's remove for_each_netdev() in geneve_destroy_tunnels() and delegate
that part to default_device_exit_batch().

Fixes: 9593172d93b9 ("geneve: Fix use-after-free in geneve_find_dev().")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250217203705.40342-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
geneve: Fix use-after-free in geneve_find_dev(). 2025-02-15T03:55:41+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2025-02-13T04:33:54+00:00 9593172d93b9f91c362baec4643003dc29802929 syzkaller reported a use-after-free in geneve_find_dev() [0] without repro. geneve_configure() links struct geneve_dev.next to net_generic(net, geneve_net_id)->geneve_list. The net here could differ from dev_net(dev) if IFLA_NET_NS_PID, IFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set. When dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally calls unregister_netdevice_queue() for each dev in the netns, and later the dev is freed. However, its geneve_dev.next is still linked to the backend UDP socket netns. Then, use-after-free will occur when another geneve dev is created in the netns. Let's call geneve_dellink() instead in geneve_destroy_tunnels(). [0]: BUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline] BUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343 Read of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441 CPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d Hardware name: linux,dummy-virt (DT) Call trace: show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x16c/0x6f0 mm/kasan/report.c:489 kasan_report+0xc0/0x120 mm/kasan/report.c:602 __asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379 geneve_find_dev drivers/net/geneve.c:1295 [inline] geneve_configure+0x234/0x858 drivers/net/geneve.c:1343 geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634 rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795 __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622 __sys_sendmsg net/socket.c:2654 [inline] __do_sys_sendmsg net/socket.c:2659 [inline] __se_sys_sendmsg net/socket.c:2657 [inline] __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600 Allocated by task 13247: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x68 mm/kasan/common.c:68 kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4298 [inline] __kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304 __kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645 alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470 rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604 rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780 __rtnl_newlink net/core/rtnetlink.c:3906 [inline] rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline] netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:713 [inline] __sock_sendmsg net/socket.c:728 [inline] ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622 __sys_sendmsg net/socket.c:2654 [inline] __do_sys_sendmsg net/socket.c:2659 [inline] __se_sys_sendmsg net/socket.c:2657 [inline] __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600 Freed by task 45: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x68 mm/kasan/common.c:68 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x48/0x68 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2353 [inline] slab_free mm/slub.c:4613 [inline] kfree+0x140/0x420 mm/slub.c:4761 kvfree+0x4c/0x68 mm/util.c:688 netdev_release+0x94/0xc8 net/core/net-sysfs.c:2065 device_release+0x98/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2b0/0x438 lib/kobject.c:737 netdev_run_todo+0xe5c/0xfc8 net/core/dev.c:11185 rtnl_unlock+0x20/0x38 net/core/rtnetlink.c:151 cleanup_net+0x4fc/0x8c0 net/core/net_namespace.c:648 process_one_work+0x700/0x1398 kernel/workqueue.c:3236 process_scheduled_works kernel/workqueue.c:3317 [inline] worker_thread+0x8c4/0xe10 kernel/workqueue.c:3398 kthread+0x4bc/0x608 kernel/kthread.c:464 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 The buggy address belongs to the object at ffff000054d6e000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 3620 bytes inside of freed 4096-byte region [ffff000054d6e000, ffff000054d6f000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x94d68 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff000016276181 flags: 0x3fffe0000000040(head|node=0|zone=0|lastcpupid=0x1ffff) page_type: f5(slab) raw: 03fffe0000000040 ffff0000c000f500 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000040004 00000001f5000000 ffff000016276181 head: 03fffe0000000040 ffff0000c000f500 dead000000000122 0000000000000000 head: 0000000000000000 0000000000040004 00000001f5000000 ffff000016276181 head: 03fffe0000000003 fffffdffc1535a01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff000054d6ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff000054d6ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff000054d6ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff000054d6ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff000054d6ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 2d07dc79fe04 ("geneve: add initial netdev driver for GENEVE tunnels") Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250213043354.91368-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> 
syzkaller reported a use-after-free in geneve_find_dev() [0]
without repro.

geneve_configure() links struct geneve_dev.next to
net_generic(net, geneve_net_id)->geneve_list.

The net here could differ from dev_net(dev) if IFLA_NET_NS_PID,
IFLA_NET_NS_FD, or IFLA_TARGET_NETNSID is set.

When dev_net(dev) is dismantled, geneve_exit_batch_rtnl() finally
calls unregister_netdevice_queue() for each dev in the netns,
and later the dev is freed.

However, its geneve_dev.next is still linked to the backend UDP
socket netns.

Then, use-after-free will occur when another geneve dev is created
in the netns.

Let's call geneve_dellink() instead in geneve_destroy_tunnels().

[0]:
BUG: KASAN: slab-use-after-free in geneve_find_dev drivers/net/geneve.c:1295 [inline]
BUG: KASAN: slab-use-after-free in geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
Read of size 2 at addr ffff000054d6ee24 by task syz.1.4029/13441

CPU: 1 UID: 0 PID: 13441 Comm: syz.1.4029 Not tainted 6.13.0-g0ad9617c78ac #24 dc35ca22c79fb82e8e7bc5c9c9adafea898b1e3d
Hardware name: linux,dummy-virt (DT)
Call trace:
 show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:466 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0x16c/0x6f0 mm/kasan/report.c:489
 kasan_report+0xc0/0x120 mm/kasan/report.c:602
 __asan_report_load2_noabort+0x20/0x30 mm/kasan/report_generic.c:379
 geneve_find_dev drivers/net/geneve.c:1295 [inline]
 geneve_configure+0x234/0x858 drivers/net/geneve.c:1343
 geneve_newlink+0xb8/0x128 drivers/net/geneve.c:1634
 rtnl_newlink_create+0x23c/0x868 net/core/rtnetlink.c:3795
 __rtnl_newlink net/core/rtnetlink.c:3906 [inline]
 rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:713 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568
 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622
 __sys_sendmsg net/socket.c:2654 [inline]
 __do_sys_sendmsg net/socket.c:2659 [inline]
 __se_sys_sendmsg net/socket.c:2657 [inline]
 __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151
 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600

Allocated by task 13247:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x30/0x68 mm/kasan/common.c:68
 kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568
 poison_kmalloc_redzone mm/kasan/common.c:377 [inline]
 __kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4298 [inline]
 __kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4304
 __kvmalloc_node_noprof+0x9c/0x230 mm/util.c:645
 alloc_netdev_mqs+0xb8/0x11a0 net/core/dev.c:11470
 rtnl_create_link+0x2b8/0xb50 net/core/rtnetlink.c:3604
 rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3780
 __rtnl_newlink net/core/rtnetlink.c:3906 [inline]
 rtnl_newlink+0x1054/0x1630 net/core/rtnetlink.c:4021
 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6911
 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2543
 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6938
 netlink_unicast_kernel net/netlink/af_netlink.c:1322 [inline]
 netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1348
 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1892
 sock_sendmsg_nosec net/socket.c:713 [inline]
 __sock_sendmsg net/socket.c:728 [inline]
 ____sys_sendmsg+0x410/0x6f8 net/socket.c:2568
 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2622
 __sys_sendmsg net/socket.c:2654 [inline]
 __do_sys_sendmsg net/socket.c:2659 [inline]
 __se_sys_sendmsg net/socket.c:2657 [inline]
 __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2657
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132
 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151
 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744
 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762
 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600

Freed by task 45:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x30/0x68 mm/kasan/common.c:68
 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:582
 poison_slab_object mm/kasan/common.c:247 [inline]
 __kasan_slab_free+0x48/0x68 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2353 [inline]
 slab_free mm/slub.c:4613 [inline]
 kfree+0x140/0x420 mm/slub.c:4761
 kvfree+0x4c/0x68 mm/util.c:688
 netdev_release+0x94/0xc8 net/core/net-sysfs.c:2065
 device_release+0x98/0x1c0
 kobject_cleanup lib/kobject.c:689 [inline]
 kobject_release lib/kobject.c:720 [inline]
 kref_put include/linux/kref.h:65 [inline]
 kobject_put+0x2b0/0x438 lib/kobject.c:737
 netdev_run_todo+0xe5c/0xfc8 net/core/dev.c:11185
 rtnl_unlock+0x20/0x38 net/core/rtnetlink.c:151
 cleanup_net+0x4fc/0x8c0 net/core/net_namespace.c:648
 process_one_work+0x700/0x1398 kernel/workqueue.c:3236
 process_scheduled_works kernel/workqueue.c:3317 [inline]
 worker_thread+0x8c4/0xe10 kernel/workqueue.c:3398
 kthread+0x4bc/0x608 kernel/kthread.c:464
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

The buggy address belongs to the object at ffff000054d6e000
 which belongs to the cache kmalloc-cg-4k of size 4096
The buggy address is located 3620 bytes inside of
 freed 4096-byte region [ffff000054d6e000, ffff000054d6f000)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x94d68
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff000016276181
flags: 0x3fffe0000000040(head|node=0|zone=0|lastcpupid=0x1ffff)
page_type: f5(slab)
raw: 03fffe0000000040 ffff0000c000f500 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000040004 00000001f5000000 ffff000016276181
head: 03fffe0000000040 ffff0000c000f500 dead000000000122 0000000000000000
head: 0000000000000000 0000000000040004 00000001f5000000 ffff000016276181
head: 03fffe0000000003 fffffdffc1535a01 ffffffffffffffff 0000000000000000
head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000054d6ed00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff000054d6ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff000054d6ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                               ^
 ffff000054d6ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff000054d6ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

Fixes: 2d07dc79fe04 ("geneve: add initial netdev driver for GENEVE tunnels")
Reported-by: syzkaller <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250213043354.91368-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>