kernel/git/stable/linux.git/drivers/net/vxlan, branch linux-6.15.y

vxlan: Add RCU read-side critical sections in the Tx path

2025-06-27T10:13:27+00:00

[ Upstream commit 804b09be09f8af4eda5346a72361459ba21fcf1b ] The Tx path does not run from an RCU read-side critical section which makes the current lockless accesses to FDB entries invalid. As far as I am aware, this has not been a problem in practice, but traces will be generated once we transition the FDB lookup to rhashtable_lookup(). Add rcu_read_{lock,unlock}() around the handling of FDB entries in the Tx path. Remove the RCU read-side critical section from vxlan_xmit_nh() as now the function is always called from an RCU read-side critical section. Reviewed-by: Petr Machata Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20250415121143.345227-2-idosch@nvidia.com Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

vxlan: Do not treat dst cache initialization errors as fatal

2025-06-27T10:13:27+00:00

[ Upstream commit 20c76dadc783759fd3819d289c72be590660cc8b ] 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 Signed-off-by: Ido Schimmel Link: https://patch.msgid.link/20250415121143.345227-14-idosch@nvidia.com Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

vxlan: vnifilter: Fix unlocked deletion of default FDB entry

2025-04-24T18:11:24+00:00

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 ebe642067455 ("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: __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: f9c4bb0b245c ("vxlan: vni filtering support on collect metadata device") Signed-off-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Link: https://patch.msgid.link/20250423145131.513029-1-idosch@nvidia.com Signed-off-by: Jakub Kicinski

treewide: Switch/rename to timer_delete[_sync]()

2025-04-05T08:30:12+00:00

timer_delete[_sync]() replaces del_timer[_sync](). Convert the whole tree over and remove the historical wrapper inlines. Conversion was done with coccinelle plus manual fixups where necessary. Signed-off-by: Thomas Gleixner Signed-off-by: Ingo Molnar

net: move misc netdev_lock flavors to a separate header

2025-03-08T17:06:50+00:00

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 Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: Use link/peer netns in newlink() of rtnl_link_ops

2025-02-21T23:28:02+00:00

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 Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219125039.18024-4-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski

rtnetlink: Pack newlink() params into struct

2025-02-21T23:28:02+00:00

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 Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski

vxlan: Join / leave MC group after remote changes

2025-02-18T12:06:43+00:00

When a vxlan netdevice is brought up, if its default remote is a multicast address, the device joins the indicated group. Therefore when the multicast remote address changes, the device should leave the current group and subscribe to the new one. Similarly when the interface used for endpoint communication is changed in a situation when multicast remote is configured. This is currently not done. Both vxlan_igmp_join() and vxlan_igmp_leave() can however fail. So it is possible that with such fix, the netdevice will end up in an inconsistent situation where the old group is not joined anymore, but joining the new group fails. Should we join the new group first, and leave the old one second, we might end up in the opposite situation, where both groups are joined. Undoing any of this during rollback is going to be similarly problematic. One solution would be to just forbid the change when the netdevice is up. However in vnifilter mode, changing the group address is allowed, and these problems are simply ignored (see vxlan_vni_update_group()): # ip link add name br up type bridge vlan_filtering 1 # ip link add vx1 up master br type vxlan external vnifilter local 192.0.2.1 dev lo dstport 4789 # bridge vni add dev vx1 vni 200 group 224.0.0.1 # tcpdump -i lo & # bridge vni add dev vx1 vni 200 group 224.0.0.2 18:55:46.523438 IP 0.0.0.0 > 224.0.0.22: igmp v3 report, 1 group record(s) 18:55:46.943447 IP 0.0.0.0 > 224.0.0.22: igmp v3 report, 1 group record(s) # bridge vni dev vni group/remote vx1 200 224.0.0.2 Having two different modes of operation for conceptually the same interface is silly, so in this patch, just do what the vnifilter code does and deal with the errors by crossing fingers real hard. The vnifilter code leaves old before joining new, and in case of join / leave failures does not roll back the configuration changes that have already been applied, but bails out of joining if it could not leave. Do the same here: leave before join, apply changes unconditionally and do not attempt to join if we couldn't leave. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni

vxlan: Drop 'changelink' parameter from vxlan_dev_configure()

2025-02-18T12:06:43+00:00

vxlan_dev_configure() only has a single caller that passes false for the changelink parameter. Drop the parameter and inline the sole value. Signed-off-by: Petr Machata Reviewed-by: Ido Schimmel Reviewed-by: Nikolay Aleksandrov Signed-off-by: Paolo Abeni

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2025-02-13T20:43:30+00:00

Cross-merge networking fixes after downstream PR (net-6.14-rc3). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski