kernel.git/net/openvswitch, branch linux-6.6.y

net: openvswitch: fix data race in ovs_vport_get_upcall_stats

2026-01-30T09:27:37Z

[ Upstream commit cc4816bdb08639e5cd9acb295a02d6f0f09736b4 ] In ovs_vport_get_upcall_stats(), some statistics protected by u64_stats_sync, are read and accumulated in ignorance of possible u64_stats_fetch_retry() events. These statistics are already accumulated by u64_stats_inc(). Fix this by reading them into temporary variables first. Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets") Signed-off-by: David Yang Acked-by: Ilya Maximets Reviewed-by: Eric Dumazet Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20260121072932.2360971-1-mmyangfl@gmail.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: openvswitch: Avoid needlessly taking the RTNL on vport destroy

2026-01-11T14:22:06Z

[ Upstream commit 5498227676303e3ffa9a3a46214af96bc3e81314 ] The openvswitch teardown code will immediately call ovs_netdev_detach_dev() in response to a NETDEV_UNREGISTER notification. It will then start the dp_notify_work workqueue, which will later end up calling the vport destroy() callback. This callback takes the RTNL to do another ovs_netdev_detach_port(), which in this case is unnecessary. This causes extra pressure on the RTNL, in some cases leading to "unregister_netdevice: waiting for XX to become free" warnings on teardown. We can straight-forwardly avoid the extra RTNL lock acquisition by checking the device flags before taking the lock, and skip the locking altogether if the IFF_OVS_DATAPATH flag has already been unset. Fixes: b07c26511e94 ("openvswitch: fix vport-netdev unregister") Tested-by: Adrian Moreno Signed-off-by: Toke Høiland-Jørgensen Acked-by: Eelco Chaudron Acked-by: Aaron Conole Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: openvswitch: fix middle attribute validation in push_nsh() action

2026-01-11T14:21:45Z

[ Upstream commit 5ace7ef87f059d68b5f50837ef3e8a1a4870c36e ] The push_nsh() action structure looks like this: OVS_ACTION_ATTR_PUSH_NSH(OVS_KEY_ATTR_NSH(OVS_NSH_KEY_ATTR_BASE,...)) The outermost OVS_ACTION_ATTR_PUSH_NSH attribute is OK'ed by the nla_for_each_nested() inside __ovs_nla_copy_actions(). The innermost OVS_NSH_KEY_ATTR_BASE/MD1/MD2 are OK'ed by the nla_for_each_nested() inside nsh_key_put_from_nlattr(). But nothing checks if the attribute in the middle is OK. We don't even check that this attribute is the OVS_KEY_ATTR_NSH. We just do a double unwrap with a pair of nla_data() calls - first time directly while calling validate_push_nsh() and the second time as part of the nla_for_each_nested() macro, which isn't safe, potentially causing invalid memory access if the size of this attribute is incorrect. The failure may not be noticed during validation due to larger netlink buffer, but cause trouble later during action execution where the buffer is allocated exactly to the size: BUG: KASAN: slab-out-of-bounds in nsh_hdr_from_nlattr+0x1dd/0x6a0 [openvswitch] Read of size 184 at addr ffff88816459a634 by task a.out/22624 CPU: 8 UID: 0 PID: 22624 6.18.0-rc7+ #115 PREEMPT(voluntary) Call Trace: dump_stack_lvl+0x51/0x70 print_address_description.constprop.0+0x2c/0x390 kasan_report+0xdd/0x110 kasan_check_range+0x35/0x1b0 __asan_memcpy+0x20/0x60 nsh_hdr_from_nlattr+0x1dd/0x6a0 [openvswitch] push_nsh+0x82/0x120 [openvswitch] do_execute_actions+0x1405/0x2840 [openvswitch] ovs_execute_actions+0xd5/0x3b0 [openvswitch] ovs_packet_cmd_execute+0x949/0xdb0 [openvswitch] genl_family_rcv_msg_doit+0x1d6/0x2b0 genl_family_rcv_msg+0x336/0x580 genl_rcv_msg+0x9f/0x130 netlink_rcv_skb+0x11f/0x370 genl_rcv+0x24/0x40 netlink_unicast+0x73e/0xaa0 netlink_sendmsg+0x744/0xbf0 __sys_sendto+0x3d6/0x450 do_syscall_64+0x79/0x2c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e Let's add some checks that the attribute is properly sized and it's the only one attribute inside the action. Technically, there is no real reason for OVS_KEY_ATTR_NSH to be there, as we know that we're pushing an NSH header already, it just creates extra nesting, but that's how uAPI works today. So, keeping as it is. Fixes: b2d0f5d5dc53 ("openvswitch: enable NSH support") Reported-by: Junvy Yang Signed-off-by: Ilya Maximets Acked-by: Eelco Chaudron echaudro@redhat.com Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20251204105334.900379-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

netfilter: nf_conncount: rework API to use sk_buff directly

2026-01-11T14:21:34Z

[ Upstream commit be102eb6a0e7c03db00e50540622f4e43b2d2844 ] When using nf_conncount infrastructure for non-confirmed connections a duplicated track is possible due to an optimization introduced since commit d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC"). In order to fix this introduce a new conncount API that receives directly an sk_buff struct. It fetches the tuple and zone and the corresponding ct from it. It comes with both existing conncount variants nf_conncount_count_skb() and nf_conncount_add_skb(). In addition remove the old API and adjust all the users to use the new one. This way, for each sk_buff struct it is possible to check if there is a ct present and already confirmed. If so, skip the add operation. Fixes: d265929930e2 ("netfilter: nf_conncount: reduce unnecessary GC") Signed-off-by: Fernando Fernandez Mancera Signed-off-by: Pablo Neira Ayuso Signed-off-by: Sasha Levin

net: openvswitch: remove never-working support for setting nsh fields

2025-12-01T10:41:46Z

[ Upstream commit dfe28c4167a9259fc0c372d9f9473e1ac95cff67 ] The validation of the set(nsh(...)) action is completely wrong. It runs through the nsh_key_put_from_nlattr() function that is the same function that validates NSH keys for the flow match and the push_nsh() action. However, the set(nsh(...)) has a very different memory layout. Nested attributes in there are doubled in size in case of the masked set(). That makes proper validation impossible. There is also confusion in the code between the 'masked' flag, that says that the nested attributes are doubled in size containing both the value and the mask, and the 'is_mask' that says that the value we're parsing is the mask. This is causing kernel crash on trying to write into mask part of the match with SW_FLOW_KEY_PUT() during validation, while validate_nsh() doesn't allocate any memory for it: BUG: kernel NULL pointer dereference, address: 0000000000000018 #PF: supervisor read access in kernel mode #PF: error_code(0x0000) - not-present page PGD 1c2383067 P4D 1c2383067 PUD 20b703067 PMD 0 Oops: Oops: 0000 [#1] SMP NOPTI CPU: 8 UID: 0 Kdump: loaded Not tainted 6.17.0-rc4+ #107 PREEMPT(voluntary) RIP: 0010:nsh_key_put_from_nlattr+0x19d/0x610 [openvswitch] Call Trace: validate_nsh+0x60/0x90 [openvswitch] validate_set.constprop.0+0x270/0x3c0 [openvswitch] __ovs_nla_copy_actions+0x477/0x860 [openvswitch] ovs_nla_copy_actions+0x8d/0x100 [openvswitch] ovs_packet_cmd_execute+0x1cc/0x310 [openvswitch] genl_family_rcv_msg_doit+0xdb/0x130 genl_family_rcv_msg+0x14b/0x220 genl_rcv_msg+0x47/0xa0 netlink_rcv_skb+0x53/0x100 genl_rcv+0x24/0x40 netlink_unicast+0x280/0x3b0 netlink_sendmsg+0x1f7/0x430 ____sys_sendmsg+0x36b/0x3a0 ___sys_sendmsg+0x87/0xd0 __sys_sendmsg+0x6d/0xd0 do_syscall_64+0x7b/0x2c0 entry_SYSCALL_64_after_hwframe+0x76/0x7e The third issue with this process is that while trying to convert the non-masked set into masked one, validate_set() copies and doubles the size of the OVS_KEY_ATTR_NSH as if it didn't have any nested attributes. It should be copying each nested attribute and doubling them in size independently. And the process must be properly reversed during the conversion back from masked to a non-masked variant during the flow dump. In the end, the only two outcomes of trying to use this action are either validation failure or a kernel crash. And if somehow someone manages to install a flow with such an action, it will most definitely not do what it is supposed to, since all the keys and the masks are mixed up. Fixing all the issues is a complex task as it requires re-writing most of the validation code. Given that and the fact that this functionality never worked since introduction, let's just remove it altogether. It's better to re-introduce it later with a proper implementation instead of trying to fix it in stable releases. Fixes: b2d0f5d5dc53 ("openvswitch: enable NSH support") Reported-by: Junvy Yang Signed-off-by: Ilya Maximets Acked-by: Eelco Chaudron Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20251112112246.95064-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: openvswitch: Fix the dead loop of MPLS parse

2025-06-19T13:28:19Z

[ Upstream commit 0bdc924bfb319fb10d1113cbf091fc26fb7b1f99 ] The unexpected MPLS packet may not end with the bottom label stack. When there are many stacks, The label count value has wrapped around. A dead loop occurs, soft lockup/CPU stuck finally. stack backtrace: UBSAN: array-index-out-of-bounds in /build/linux-0Pa0xK/linux-5.15.0/net/openvswitch/flow.c:662:26 index -1 is out of range for type '__be32 [3]' CPU: 34 PID: 0 Comm: swapper/34 Kdump: loaded Tainted: G OE 5.15.0-121-generic #131-Ubuntu Hardware name: Dell Inc. PowerEdge C6420/0JP9TF, BIOS 2.12.2 07/14/2021 Call Trace: show_stack+0x52/0x5c dump_stack_lvl+0x4a/0x63 dump_stack+0x10/0x16 ubsan_epilogue+0x9/0x36 __ubsan_handle_out_of_bounds.cold+0x44/0x49 key_extract_l3l4+0x82a/0x840 [openvswitch] ? kfree_skbmem+0x52/0xa0 key_extract+0x9c/0x2b0 [openvswitch] ovs_flow_key_extract+0x124/0x350 [openvswitch] ovs_vport_receive+0x61/0xd0 [openvswitch] ? kernel_init_free_pages.part.0+0x4a/0x70 ? get_page_from_freelist+0x353/0x540 netdev_port_receive+0xc4/0x180 [openvswitch] ? netdev_port_receive+0x180/0x180 [openvswitch] netdev_frame_hook+0x1f/0x40 [openvswitch] __netif_receive_skb_core.constprop.0+0x23a/0xf00 __netif_receive_skb_list_core+0xfa/0x240 netif_receive_skb_list_internal+0x18e/0x2a0 napi_complete_done+0x7a/0x1c0 bnxt_poll+0x155/0x1c0 [bnxt_en] __napi_poll+0x30/0x180 net_rx_action+0x126/0x280 ? bnxt_msix+0x67/0x80 [bnxt_en] handle_softirqs+0xda/0x2d0 irq_exit_rcu+0x96/0xc0 common_interrupt+0x8e/0xa0 Fixes: fbdcdd78da7c ("Change in Openvswitch to support MPLS label depth of 3 in ingress direction") Signed-off-by: Faicker Mo Acked-by: Ilya Maximets Reviewed-by: Aaron Conole Link: https://patch.msgid.link/259D3404-575D-4A6D-B263-1DF59A67CF89@zenlayer.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

openvswitch: Fix unsafe attribute parsing in output_userspace()

2025-05-18T06:24:04Z

commit 6beb6835c1fbb3f676aebb51a5fee6b77fed9308 upstream. This patch replaces the manual Netlink attribute iteration in output_userspace() with nla_for_each_nested(), which ensures that only well-formed attributes are processed. Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.") Signed-off-by: Eelco Chaudron Acked-by: Ilya Maximets Acked-by: Aaron Conole Link: https://patch.msgid.link/0bd65949df61591d9171c0dc13e42cea8941da10.1746541734.git.echaudro@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

net: openvswitch: fix nested key length validation in the set() action

2025-04-25T08:45:42Z

[ Upstream commit 65d91192aa66f05710cfddf6a14b5a25ee554dba ] It's not safe to access nla_len(ovs_key) if the data is smaller than the netlink header. Check that the attribute is OK first. Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.") Reported-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b07a9da40df1576b8048 Tested-by: syzbot+b07a9da40df1576b8048@syzkaller.appspotmail.com Signed-off-by: Ilya Maximets Reviewed-by: Eelco Chaudron Acked-by: Aaron Conole Link: https://patch.msgid.link/20250412104052.2073688-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

tunnels: Accept PACKET_HOST in skb_tunnel_check_pmtu().

2025-04-10T12:37:40Z

[ Upstream commit 8930424777e43257f5bf6f0f0f53defd0d30415c ] Because skb_tunnel_check_pmtu() doesn't handle PACKET_HOST packets, commit 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") forced skb->pkt_type to PACKET_OUTGOING for openvswitch packets that are sent using the OVS_ACTION_ATTR_OUTPUT action. This allowed such packets to invoke the iptunnel_pmtud_check_icmp() or iptunnel_pmtud_check_icmpv6() helpers and thus trigger PMTU update on the input device. However, this also broke other parts of PMTU discovery. Since these packets don't have the PACKET_HOST type anymore, they won't trigger the sending of ICMP Fragmentation Needed or Packet Too Big messages to remote hosts when oversized (see the skb_in->pkt_type condition in __icmp_send() for example). These two skb->pkt_type checks are therefore incompatible as one requires skb->pkt_type to be PACKET_HOST, while the other requires it to be anything but PACKET_HOST. It makes sense to not trigger ICMP messages for non-PACKET_HOST packets as these messages should be generated only for incoming l2-unicast packets. However there doesn't seem to be any reason for skb_tunnel_check_pmtu() to ignore PACKET_HOST packets. Allow both cases to work by allowing skb_tunnel_check_pmtu() to work on PACKET_HOST packets and not overriding skb->pkt_type in openvswitch anymore. Fixes: 30a92c9e3d6b ("openvswitch: Set the skbuff pkt_type for proper pmtud support.") Fixes: 4cb47a8644cc ("tunnels: PMTU discovery support for directly bridged IP packets") Signed-off-by: Guillaume Nault Reviewed-by: Stefano Brivio Reviewed-by: Aaron Conole Tested-by: Aaron Conole Link: https://patch.msgid.link/eac941652b86fddf8909df9b3bf0d97bc9444793.1743208264.git.gnault@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: openvswitch: remove misbehaving actions length check

2025-03-22T19:50:39Z

[ Upstream commit a1e64addf3ff9257b45b78bc7d743781c3f41340 ] The actions length check is unreliable and produces different results depending on the initial length of the provided netlink attribute and the composition of the actual actions inside of it. For example, a user can add 4088 empty clone() actions without triggering -EMSGSIZE, on attempt to add 4089 such actions the operation will fail with the -EMSGSIZE verdict. However, if another 16 KB of other actions will be *appended* to the previous 4089 clone() actions, the check passes and the flow is successfully installed into the openvswitch datapath. The reason for a such a weird behavior is the way memory is allocated. When ovs_flow_cmd_new() is invoked, it calls ovs_nla_copy_actions(), that in turn calls nla_alloc_flow_actions() with either the actual length of the user-provided actions or the MAX_ACTIONS_BUFSIZE. The function adds the size of the sw_flow_actions structure and then the actually allocated memory is rounded up to the closest power of two. So, if the user-provided actions are larger than MAX_ACTIONS_BUFSIZE, then MAX_ACTIONS_BUFSIZE + sizeof(*sfa) rounded up is 32K + 24 -> 64K. Later, while copying individual actions, we look at ksize(), which is 64K, so this way the MAX_ACTIONS_BUFSIZE check is not actually triggered and the user can easily allocate almost 64 KB of actions. However, when the initial size is less than MAX_ACTIONS_BUFSIZE, but the actions contain ones that require size increase while copying (such as clone() or sample()), then the limit check will be performed during the reserve_sfa_size() and the user will not be allowed to create actions that yield more than 32 KB internally. This is one part of the problem. The other part is that it's not actually possible for the userspace application to know beforehand if the particular set of actions will be rejected or not. Certain actions require more space in the internal representation, e.g. an empty clone() takes 4 bytes in the action list passed in by the user, but it takes 12 bytes in the internal representation due to an extra nested attribute, and some actions require less space in the internal representations, e.g. set(tunnel(..)) normally takes 64+ bytes in the action list provided by the user, but only needs to store a single pointer in the internal implementation, since all the data is stored in the tunnel_info structure instead. And the action size limit is applied to the internal representation, not to the action list passed by the user. So, it's not possible for the userpsace application to predict if the certain combination of actions will be rejected or not, because it is not possible for it to calculate how much space these actions will take in the internal representation without knowing kernel internals. All that is causing random failures in ovs-vswitchd in userspace and inability to handle certain traffic patterns as a result. For example, it is reported that adding a bit more than a 1100 VMs in an OpenStack setup breaks the network due to OVS not being able to handle ARP traffic anymore in some cases (it tries to install a proper datapath flow, but the kernel rejects it with -EMSGSIZE, even though the action list isn't actually that large.) Kernel behavior must be consistent and predictable in order for the userspace application to use it in a reasonable way. ovs-vswitchd has a mechanism to re-direct parts of the traffic and partially handle it in userspace if the required action list is oversized, but that doesn't work properly if we can't actually tell if the action list is oversized or not. Solution for this is to check the size of the user-provided actions instead of the internal representation. This commit just removes the check from the internal part because there is already an implicit size check imposed by the netlink protocol. The attribute can't be larger than 64 KB. Realistically, we could reduce the limit to 32 KB, but we'll be risking to break some existing setups that rely on the fact that it's possible to create nearly 64 KB action lists today. Vast majority of flows in real setups are below 100-ish bytes. So removal of the limit will not change real memory consumption on the system. The absolutely worst case scenario is if someone adds a flow with 64 KB of empty clone() actions. That will yield a 192 KB in the internal representation consuming 256 KB block of memory. However, that list of actions is not meaningful and also a no-op. Real world very large action lists (that can occur for a rare cases of BUM traffic handling) are unlikely to contain a large number of clones and will likely have a lot of tunnel attributes making the internal representation comparable in size to the original action list. So, it should be fine to just remove the limit. Commit in the 'Fixes' tag is the first one that introduced the difference between internal representation and the user-provided action lists, but there were many more afterwards that lead to the situation we have today. Fixes: 7d5437c709de ("openvswitch: Add tunneling interface.") Signed-off-by: Ilya Maximets Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20250308004609.2881861-1-i.maximets@ovn.org Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin