linux/net/openvswitch, branch v6.15

openvswitch: Fix unsafe attribute parsing in output_userspace()

2025-05-07T23:51:02Z

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

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

2025-04-14T23:15:38Z

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

Merge tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux

2025-04-08T19:09:28Z

Pull CRC cleanups from Eric Biggers: "Finish cleaning up the CRC kconfig options by removing the remaining unnecessary prompts and an unnecessary 'default y', removing CONFIG_LIBCRC32C, and documenting all the CRC library options" * tag 'crc-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiggers/linux: lib/crc: remove CONFIG_LIBCRC32C lib/crc: document all the CRC library kconfig options lib/crc: remove unnecessary prompt for CONFIG_CRC_ITU_T lib/crc: remove unnecessary prompt for CONFIG_CRC_T10DIF lib/crc: remove unnecessary prompt for CONFIG_CRC16 lib/crc: remove unnecessary prompt for CONFIG_CRC_CCITT lib/crc: remove unnecessary prompt for CONFIG_CRC32 and drop 'default y'

lib/crc: remove CONFIG_LIBCRC32C

2025-04-04T18:31:42Z

Now that LIBCRC32C does nothing besides select CRC32, make every option that selects LIBCRC32C instead select CRC32 directly. Then remove LIBCRC32C. Reviewed-by: Christoph Hellwig Reviewed-by: "Martin K. Petersen" Acked-by: Ard Biesheuvel Link: https://lore.kernel.org/r/20250401221600.24878-8-ebiggers@kernel.org Signed-off-by: Eric Biggers

tunnels: Accept PACKET_HOST in skb_tunnel_check_pmtu().

2025-04-03T00:22:39Z

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

net: openvswitch: fix kernel-doc warnings in internal headers

2025-03-24T16:30:21Z

Some field descriptions were missing, some were not very accurate. Not touching the uAPI header or .c files for now. Formatting of those comments isn't great in general, but at least they are not missing anything now. Before: $ ./scripts/kernel-doc -none -Wall net/openvswitch/*.h 2>&1 | wc -l 16 After: $ ./scripts/kernel-doc -none -Wall net/openvswitch/*.h 2>&1 | wc -l 0 Signed-off-by: Ilya Maximets Acked-by: Eelco Chaudron Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20250320224431.252489-1-i.maximets@ovn.org Signed-off-by: Jakub Kicinski

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

2025-03-13T22:08:11Z

Cross-merge networking fixes after downstream PR (net-6.14-rc6). Conflicts: tools/testing/selftests/drivers/net/ping.py 75cc19c8ff89 ("selftests: drv-net: add xdp cases for ping.py") de94e8697405 ("selftests: drv-net: store addresses in dict indexed by ipver") https://lore.kernel.org/netdev/20250311115758.17a1d414@canb.auug.org.au/ net/core/devmem.c a70f891e0fa0 ("net: devmem: do not WARN conditionally after netdev_rx_queue_restart()") 1d22d3060b9b ("net: drop rtnl_lock for queue_mgmt operations") https://lore.kernel.org/netdev/20250313114929.43744df1@canb.auug.org.au/ Adjacent changes: tools/testing/selftests/net/Makefile 6f50175ccad4 ("selftests: Add IPv6 link-local address generation tests for GRE devices.") 2e5584e0f913 ("selftests/net: expand cmsg_ipv6.sh with ipv4") drivers/net/ethernet/broadcom/bnxt/bnxt.c 661958552eda ("eth: bnxt: do not use BNXT_VNIC_NTUPLE unconditionally in queue restart logic") fe96d717d38e ("bnxt_en: Extend queue stop/start for TX rings") Signed-off-by: Paolo Abeni

Revert "openvswitch: switch to per-action label counting in conntrack"

2025-03-13T09:29:34Z

Currently, ovs_ct_set_labels() is only called for confirmed conntrack entries (ct) within ovs_ct_commit(). However, if the conntrack entry does not have the labels_ext extension, attempting to allocate it in ovs_ct_get_conn_labels() for a confirmed entry triggers a warning in nf_ct_ext_add(): WARN_ON(nf_ct_is_confirmed(ct)); This happens when the conntrack entry is created externally before OVS increments net->ct.labels_used. The issue has become more likely since commit fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack"), which changed to use per-action label counting and increment net->ct.labels_used when a flow with ct action is added. Since there’s no straightforward way to fully resolve this issue at the moment, this reverts the commit to avoid breaking existing use cases. Fixes: fcb1aa5163b1 ("openvswitch: switch to per-action label counting in conntrack") Reported-by: Jianbo Liu Signed-off-by: Xin Long Acked-by: Aaron Conole Link: https://patch.msgid.link/1bdeb2f3a812bca016a225d3de714427b2cd4772.1741457143.git.lucien.xin@gmail.com Signed-off-by: Paolo Abeni

net: openvswitch: remove misbehaving actions length check

2025-03-13T09:29:18Z

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

net: rename netns_local to netns_immutable

2025-03-04T11:44:48Z

The name 'netns_local' is confusing. A following commit will export it via netlink, so let's use a more explicit name. Reported-by: Eric Dumazet Suggested-by: Kuniyuki Iwashima Signed-off-by: Nicolas Dichtel Reviewed-by: Kuniyuki Iwashima Signed-off-by: Paolo Abeni