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: 8bcdc4f3a2 ("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>
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: a3a48de5ea ("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>
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: f9c4bb0b24 ("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>
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: f9c4bb0b24 ("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>
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: 4cb47a8644 ("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>
Initially, a dedicated workqueue was used to defer calling
udp_tunnel_sock_release(vxlan_sock->sock) and kfree(vxlan_sock).
Later, commit 0412bd931f ("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 ca065d0cf8 ("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>
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>
Commit 3cf7203ca6 ("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>
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: 5602c48cf8 ("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>
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>
None of the udp_tunnel users need struct socket in their
fast paths; it is only used for tunnel setup / teardown.
Even udp_tunnel_{push,drop}_rx_port() do not need struct socket.
Let's change udp_tunnel_{push,drop}_rx_port() to take struct
sock instead of struct socket.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260502031401.3557229-5-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
None of the udp_tunnel users need struct socket in their
fast paths; it is only used for tunnel setup / teardown.
Even udp_tunnel6_dst_lookup() does not need struct socket.
Let's change udp_tunnel6_dst_lookup() to take struct sock
instead of struct socket.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260502031401.3557229-4-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
None of the udp_tunnel users need struct socket in their
fast paths; it is only used for tunnel setup / teardown.
Even setup_udp_tunnel_sock() does not need struct socket.
Let's change setup_udp_tunnel_sock() to take struct sock
instead of struct socket.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260502031401.3557229-3-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
None of the udp_tunnel users need struct socket in their
fast paths; it is only used for tunnel setup / teardown.
While the UDP tunnel interface accepts struct socket, this
encourages users to store the pointer unnecessarily. This
leads to extra dereferences when accessing struct sock fields
(e.g., sk->sk_user_data instead of sock->sk->sk_user_data).
Furthermore, these dereferences necessitate synchronize_rcu()
in udp_tunnel_sock_release() to protect the fast paths from
sock_orphan() setting sk->sk_socket to NULL.
This overhead can be avoided if users store the struct sock
pointer directly in their private structures.
As a prep, let's change udp_tunnel_sock_release() to take
struct sock instead of struct socket.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20260502031401.3557229-2-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
IPv6 must be enabled or otherwise neigh_reduce() might cause a kernel
panic. This was prevented by a check on in6_dev. Use ipv6_mod_enabled()
instead as it is cleaner and also consistent with the code at
route_shortcircuit().
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260330121033.4479-1-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As IPv6 is built-in only, the ipv6_stub infrastructure is no longer
necessary.
Convert all drivers currently utilizing ipv6_stub to make direct
function calls. The fallback functions introduced previously will
prevent linkage errors when CONFIG_IPV6 is disabled.
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Tested-by: Ricardo B. Marlière <rbm@suse.com>
Reviewed-by: Jason A. Donenfeld <Jason@zx2c4.com>
Reviewed-by: Antonio Quartulli <antonio@openvpn.net>
Reviewed-by: Edward Cree <ecree.xilinx@gmail.com>
Link: https://patch.msgid.link/20260325120928.15848-7-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
vxlan_na_create() walks ND options according to option-provided
lengths. A malformed option can make the parser advance beyond the
computed option span or use a too-short source LLADDR option payload.
Validate option lengths against the remaining NS option area before
advancing, and only read source LLADDR when the option is large enough
for an Ethernet address.
Fixes: 4b29dba9c0 ("vxlan: fix nonfunctional neigh_reduce()")
Cc: stable@vger.kernel.org
Reported-by: Yifan Wu <yifanwucs@gmail.com>
Reported-by: Juefei Pu <tomapufckgml@gmail.com>
Tested-by: Ao Zhou <n05ec@lzu.edu.cn>
Co-developed-by: Yuan Tan <tanyuan98@outlook.com>
Signed-off-by: Yuan Tan <tanyuan98@outlook.com>
Suggested-by: Xin Liu <bird@lzu.edu.cn>
Signed-off-by: Yang Yang <n05ec@lzu.edu.cn>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20260326034441.2037420-4-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When booting with the 'ipv6.disable=1' parameter, the nd_tbl is never
initialized because inet6_init() exits before ndisc_init() is called
which initializes it. If an IPv6 packet is injected into the interface,
route_shortcircuit() is called and a NULL pointer dereference happens on
neigh_lookup().
BUG: kernel NULL pointer dereference, address: 0000000000000380
Oops: Oops: 0000 [#1] SMP NOPTI
[...]
RIP: 0010:neigh_lookup+0x20/0x270
[...]
Call Trace:
<TASK>
vxlan_xmit+0x638/0x1ef0 [vxlan]
dev_hard_start_xmit+0x9e/0x2e0
__dev_queue_xmit+0xbee/0x14e0
packet_sendmsg+0x116f/0x1930
__sys_sendto+0x1f5/0x200
__x64_sys_sendto+0x24/0x30
do_syscall_64+0x12f/0x1590
entry_SYSCALL_64_after_hwframe+0x76/0x7e
Fix this by adding an early check on route_shortcircuit() when protocol
is ETH_P_IPV6. Note that ipv6_mod_enabled() cannot be used here because
VXLAN can be built-in even when IPv6 is built as a module.
Fixes: e15a00aafa ("vxlan: add ipv6 route short circuit support")
Signed-off-by: Fernando Fernandez Mancera <fmancera@suse.de>
Link: https://patch.msgid.link/20260304120357.9778-2-fmancera@suse.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This was done entirely with mindless brute force, using
git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'
to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.
Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.
For the same reason the 'flex' versions will be done as a separate
conversion.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
On 64bit arches, struct u64_stats_sync is empty and provides no help
against load/store tearing. memcpy() should not be considered atomic
against u64 values. Use u64_stats_copy() instead.
Signed-off-by: David Yang <mmyangfl@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20260120092137.2161162-5-mmyangfl@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Neither sock4 nor sock6 pointers are guaranteed to be non-NULL in
vxlan_xmit_one, e.g. if the iface is brought down. This can lead to the
following NULL dereference:
BUG: kernel NULL pointer dereference, address: 0000000000000010
Oops: Oops: 0000 [#1] SMP NOPTI
RIP: 0010:vxlan_xmit_one+0xbb3/0x1580
Call Trace:
vxlan_xmit+0x429/0x610
dev_hard_start_xmit+0x55/0xa0
__dev_queue_xmit+0x6d0/0x7f0
ip_finish_output2+0x24b/0x590
ip_output+0x63/0x110
Mentioned commits changed the code path in vxlan_xmit_one and as a side
effect the sock4/6 pointer validity checks in vxlan(6)_get_route were
lost. Fix this by adding back checks.
Since both commits being fixed were released in the same version (v6.7)
and are strongly related, bundle the fixes in a single commit.
Reported-by: Liang Li <liali@redhat.com>
Fixes: 6f19b2c136 ("vxlan: use generic function for tunnel IPv4 route lookup")
Fixes: 2aceb896ee ("vxlan: use generic function for tunnel IPv6 route lookup")
Cc: Beniamino Galvani <b.galvani@gmail.com>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20251126102627.74223-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
first_remote_rcu() can return NULL if the FDB entry points to an FDB
nexthop group instead of a remote destination. However, unlike other
users of first_remote_rcu(), NPD cannot currently happen in
vxlan_fdb_find_uc() as it is only invoked by one driver which vetoes the
creation of FDB nexthops.
Make the function more robust by making sure the remote destination is
only dereferenced if it is not NULL.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Wang Liang <wangliang74@huawei.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250908075141.125087-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When the "proxy" option is enabled on a VXLAN device, the device will
suppress ARP requests and IPv6 Neighbor Solicitation messages if it is
able to reply on behalf of the remote host. That is, if a matching and
valid neighbor entry is configured on the VXLAN device whose MAC address
is not behind the "any" remote (0.0.0.0 / ::).
The code currently assumes that the FDB entry for the neighbor's MAC
address points to a valid remote destination, but this is incorrect if
the entry is associated with an FDB nexthop group. This can result in a
NPD [1][3] which can be reproduced using [2][4].
Fix by checking that the remote destination exists before dereferencing
it.
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 4 UID: 0 PID: 365 Comm: arping Not tainted 6.17.0-rc2-virtme-g2a89cb21162c #2 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_xmit+0xb58/0x15f0
[...]
Call Trace:
<TASK>
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
packet_sendmsg+0x113a/0x1850
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
[2]
#!/bin/bash
ip address add 192.0.2.1/32 dev lo
ip nexthop add id 1 via 192.0.2.2 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 4789 proxy
ip neigh add 192.0.2.3 lladdr 00:11:22:33:44:55 nud perm dev vx0
bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10
arping -b -c 1 -s 192.0.2.1 -I vx0 192.0.2.3
[3]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 372 Comm: ndisc6 Not tainted 6.17.0-rc2-virtmne-g6ee90cb26014 #3 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1v996), BIOS 1.17.0-4.fc41 04/01/2x014
RIP: 0010:vxlan_xmit+0x803/0x1600
[...]
Call Trace:
<TASK>
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
ip6_finish_output2+0x210/0x6c0
ip6_finish_output+0x1af/0x2b0
ip6_mr_output+0x92/0x3e0
ip6_send_skb+0x30/0x90
rawv6_sendmsg+0xe6e/0x12e0
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
RIP: 0033:0x7f383422ec77
[4]
#!/bin/bash
ip address add 2001:db8:1::1/128 dev lo
ip nexthop add id 1 via 2001:db8:1::1 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 2001:db8:1::1 dstport 4789 proxy
ip neigh add 2001:db8:1::3 lladdr 00:11:22:33:44:55 nud perm dev vx0
bridge fdb add 00:11:22:33:44:55 dev vx0 self static nhid 10
ndisc6 -r 1 -s 2001:db8:1::1 -w 1 2001:db8:1::3 vx0
Fixes: 1274e1cc42 ("vxlan: ecmp support for mac fdb entries")
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250901065035.159644-3-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
VXLAN FDB entries can point to either a remote destination or an FDB
nexthop group. The latter is usually used in EVPN deployments where
learning is disabled.
However, when learning is enabled, an incoming packet might try to
refresh an FDB entry that points to an FDB nexthop group and therefore
does not have a remote. Such packets should be dropped, but they are
only dropped after dereferencing the non-existent remote, resulting in a
NPD [1] which can be reproduced using [2].
Fix by dropping such packets earlier. Remove the misleading comment from
first_remote_rcu().
[1]
BUG: kernel NULL pointer dereference, address: 0000000000000000
[...]
CPU: 13 UID: 0 PID: 361 Comm: mausezahn Not tainted 6.17.0-rc1-virtme-g9f6b606b6b37 #1 PREEMPT(voluntary)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-4.fc41 04/01/2014
RIP: 0010:vxlan_snoop+0x98/0x1e0
[...]
Call Trace:
<TASK>
vxlan_encap_bypass+0x209/0x240
encap_bypass_if_local+0xb1/0x100
vxlan_xmit_one+0x1375/0x17e0
vxlan_xmit+0x6b4/0x15f0
dev_hard_start_xmit+0x5d/0x1c0
__dev_queue_xmit+0x246/0xfd0
packet_sendmsg+0x113a/0x1850
__sock_sendmsg+0x38/0x70
__sys_sendto+0x126/0x180
__x64_sys_sendto+0x24/0x30
do_syscall_64+0xa4/0x260
entry_SYSCALL_64_after_hwframe+0x4b/0x53
[2]
#!/bin/bash
ip address add 192.0.2.1/32 dev lo
ip address add 192.0.2.2/32 dev lo
ip nexthop add id 1 via 192.0.2.3 fdb
ip nexthop add id 10 group 1 fdb
ip link add name vx0 up type vxlan id 10010 local 192.0.2.1 dstport 12345 localbypass
ip link add name vx1 up type vxlan id 10020 local 192.0.2.2 dstport 54321 learning
bridge fdb add 00:11:22:33:44:55 dev vx0 self static dst 192.0.2.2 port 54321 vni 10020
bridge fdb add 00:aa:bb:cc:dd:ee dev vx1 self static nhid 10
mausezahn vx0 -a 00:aa:bb:cc:dd:ee -b 00:11:22:33:44:55 -c 1 -q
Fixes: 1274e1cc42 ("vxlan: ecmp support for mac fdb entries")
Reported-by: Marlin Cremers <mcremers@cloudbear.nl>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250901065035.159644-2-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
The IFLA_VXLAN_ID data has been converted to local variable vni in
vxlan_nl2conf(), there is no need to do it again when set conf->vni.
Signed-off-by: Wang Liang <wangliang74@huawei.com>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Petr Machata <petrm@nvidia.com>
Link: https://patch.msgid.link/20250722093049.1527505-1-wangliang74@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add the nlmsg_for_each_attr_type() macro to simplify iteration over
attributes of a specific type in a Netlink message.
Convert existing users in vxlan and nfsd to use the new macro.
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Carolina Jubran <cjubran@nvidia.com>
Signed-off-by: Mark Bloch <mbloch@nvidia.com>
Link: https://patch.msgid.link/20250629142138.361537-2-mbloch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
We won't be able to sleep soon in vxlan_offload_rx_ports and won't be
able to grab sock_lock. Instead of having separate spinlock to
manage sockets, rely on rtnl lock. This is similar to how geneve
manages its sockets.
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250616162117.287806-3-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Locally-generated MC packets have so far not been subject to MC routing.
Instead an MC-enabled installation would maintain the MC routing tables,
and separately from that the list of interfaces to send packets to as part
of the VXLAN FDB and MDB.
In a previous patch, a ip_mr_output() and ip6_mr_output() routines were
added for IPv4 and IPv6. All locally generated MC traffic is now passed
through these functions. For reasons of backward compatibility, an SKB
(IPCB / IP6CB) flag guards the actual MC routing.
This patch adds logic to set the flag, and the UAPI to enable the behavior.
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/d899655bb7e9b2521ee8c793e67056b9fd02ba12.1750113335.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>
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>
Move this API to the canonical timer_*() namespace.
[ tglx: Redone against pre rc1 ]
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
Cross-merge networking fixes after downstream PR (net-6.15-rc4).
This pull includes wireless and a fix to vxlan which isn't
in Linus's tree just yet. The latter creates with a silent conflict
/ build breakage, so merging it now to avoid causing problems.
drivers/net/vxlan/vxlan_vnifilter.c
094adad913 ("vxlan: Use a single lock to protect the FDB table")
087a9eb9e5 ("vxlan: vnifilter: Fix unlocked deletion of default FDB entry")
https://lore.kernel.org/20250423145131.513029-1-idosch@nvidia.com
No "normal" conflicts, or adjacent changes.
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a VNI is deleted from a VXLAN device in 'vnifilter' mode, the FDB
entry associated with the default remote (assuming one was configured)
is deleted without holding the hash lock. This is wrong and will result
in a warning [1] being generated by the lockdep annotation that was
added by commit ebe6420674 ("vxlan: Create wrappers for FDB lookup").
Reproducer:
# ip link add vx0 up type vxlan dstport 4789 external vnifilter local 192.0.2.1
# bridge vni add vni 10010 remote 198.51.100.1 dev vx0
# bridge vni del vni 10010 dev vx0
Fix by acquiring the hash lock before the deletion and releasing it
afterwards. Blame the original commit that introduced the issue rather
than the one that exposed it.
[1]
WARNING: CPU: 3 PID: 392 at drivers/net/vxlan/vxlan_core.c:417 vxlan_find_mac+0x17f/0x1a0
[...]
RIP: 0010:vxlan_find_mac+0x17f/0x1a0
[...]
Call Trace:
<TASK>
__vxlan_fdb_delete+0xbe/0x560
vxlan_vni_delete_group+0x2ba/0x940
vxlan_vni_del.isra.0+0x15f/0x580
vxlan_process_vni_filter+0x38b/0x7b0
vxlan_vnifilter_process+0x3bb/0x510
rtnetlink_rcv_msg+0x2f7/0xb70
netlink_rcv_skb+0x131/0x360
netlink_unicast+0x426/0x710
netlink_sendmsg+0x75a/0xc20
__sock_sendmsg+0xc1/0x150
____sys_sendmsg+0x5aa/0x7b0
___sys_sendmsg+0xfc/0x180
__sys_sendmsg+0x121/0x1b0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x4b/0x53
Fixes: f9c4bb0b24 ("vxlan: vni filtering support on collect metadata device")
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/20250423145131.513029-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
FDB entries are currently stored in a hash table with a fixed number of
buckets (256), resulting in performance degradation as the number of
entries grows. Solve this by converting the driver to use rhashtable
which maintains more or less constant performance regardless of the
number of entries.
Measured transmitted packets per second using a single pktgen thread
with varying number of entries when the transmitted packet always hits
the default entry (worst case):
Number of entries | Improvement
------------------|------------
1k | +1.12%
4k | +9.22%
16k | +55%
64k | +585%
256k | +2460%
In addition, the change reduces the size of the VXLAN device structure
from 2584 bytes to 672 bytes.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-16-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In preparation for converting the FDB table to rhashtable, introduce a
key structure that includes the MAC address and source VNI.
No functional changes intended.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-15-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
FDB entries are allocated in an atomic context as they can be added from
the data path when learning is enabled.
After converting the FDB hash table to rhashtable, the insertion rate
will be much higher (*) which will entail a much higher rate of per-CPU
allocations via dst_cache_init().
When adding a large number of entries (e.g., 256k) in a batch, a small
percentage (< 0.02%) of these per-CPU allocations will fail [1]. This
does not happen with the current code since the insertion rate is low
enough to give the per-CPU allocator a chance to asynchronously create
new chunks of per-CPU memory.
Given that:
a. Only a small percentage of these per-CPU allocations fail.
b. The scenario where this happens might not be the most realistic one.
c. The driver can work correctly without dst caches. The dst_cache_*()
APIs first check that the dst cache was properly initialized.
d. The dst caches are not always used (e.g., 'tos inherit').
It seems reasonable to not treat these allocation failures as fatal.
Therefore, do not bail when dst_cache_init() fails and suppress warnings
by specifying '__GFP_NOWARN'.
[1] percpu: allocation failed, size=40 align=8 atomic=1, atomic alloc failed, no space left
(*) 97% reduction in average latency of vxlan_fdb_update() when adding
256k entries in a batch.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-14-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
__vxlan_find_mac() is called from both the data path (e.g., during
learning) and the control path (e.g., when replacing an entry). The
function is missing lockdep annotations to make sure that the FDB hash
lock is held during FDB updates.
Rename __vxlan_find_mac() to vxlan_find_mac_rcu() to reflect the fact
that it should be called from an RCU read-side critical section and call
it from vxlan_find_mac() which checks that the FDB hash lock is held.
Change callers to invoke the appropriate function.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-13-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
vxlan_find_mac() is only expected to be called from the Tx path as it
updates the 'used' timestamp. Rename it to vxlan_find_mac_tx() to
reflect that and to avoid incorrect updates of this timestamp like those
addressed by commit 9722f834fe ("vxlan: Avoid unnecessary updates to
FDB 'used' time").
No functional changes intended.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-12-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Instead of holding the FDB hash lock when traversing the FDB linked list
during flushing, use RCU and only acquire the lock for entries that need
to be flushed.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-11-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Instead of holding the FDB hash lock when traversing the FDB linked list
during garbage collection, use RCU and only acquire the lock for entries
that need to be removed (aged out).
Avoid races by using hlist_unhashed() to check that the entry has not
been removed from the list by another thread.
Note that vxlan_fdb_destroy() uses hlist_del_init_rcu() to remove an
entry from the list which should cause list_unhashed() to return true.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-10-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
In preparation for removing the fixed size hash table, convert FDB entry
traversal to use the newly added FDB linked list.
No functional changes intended.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-9-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, FDB entries are stored in a hash table with a fixed number of
buckets. The table is used for both lookups and entry traversal.
Subsequent patches will convert the table to rhashtable which is not
suitable for entry traversal.
In preparation for this conversion, add FDB entries to a linked list.
Subsequent patches will convert the driver to use this list when
traversing entries during dump, flush, etc.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-8-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the VXLAN driver stores FDB entries in a hash table with a
fixed number of buckets (256). Subsequent patches are going to convert
this table to rhashtable with a linked list for entry traversal, as
rhashtable is more scalable.
In preparation for this conversion, move from a per-bucket spin lock to
a single spin lock that protects the entire FDB table.
The per-bucket spin locks were introduced by commit fe1e0713bb
("vxlan: Use FDB_HASH_SIZE hash_locks to reduce contention") citing
"huge contention when inserting/deleting vxlan_fdbs into the fdb_head".
It is not clear from the commit message which code path was holding the
spin lock for long periods of time, but the obvious suspect is the FDB
cleanup routine (vxlan_cleanup()) that periodically traverses the entire
table in order to delete aged-out entries.
This will be solved by subsequent patches that will convert the FDB
cleanup routine to traverse the linked list of FDB entries using RCU,
only acquiring the spin lock when deleting an aged-out entry.
The change reduces the size of the VXLAN device structure from 3600
bytes to 2576 bytes.
Reviewed-by: Petr Machata <petrm@nvidia.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250415121143.345227-7-idosch@nvidia.com
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
