kernel/git/stable/linux.git/net/openvswitch/datapath.h, branch linux-6.12.y

openvswitch: Fix CT limit teardown use-after-free

2026-09-14T11:30:57+00:00

[ Upstream commit 403f96c32c9e24600093d7d0c61c17daeedca957 ] Packet processing uses CT limit state under RCU, while netns teardown frees that state under ovs_mutex. The CT limit pointer was neither removed from readers nor protected by a grace period, allowing packet processing to dereference the freed state. An unprivileged user can trigger this bug from a user and network namespace, causing a slab-use-after-free in ovs_ct_execute() when the netns is torn down. Publish the CT limit pointer through RCU, remove it before teardown, and wait for readers before freeing its contents. Keep ovs_mutex around individual CT limit updates, and use the RCU read-side lock while GET traverses the RCU-protected limit lists. Netns teardown detaches the RCU-protected CT limit state in the pernet .pre_exit callback while holding ovs_mutex. The pernet core guarantees an RCU grace period between the .pre_exit and .exit callbacks, so the .exit callback completes the teardown without adding any extra synchronization. The netlink command handlers do not need NULL checks because the userspace netlink socket holds an active reference to its network namespace while a request is processed. The per-netns exit path therefore cannot run concurrently with SET, DEL, or GET for that socket's namespace. Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit") Cc: stable@vger.kernel.org Reported-by: Vega Link: https://lore.kernel.org/all/cover.1784711445.git.xuyuqiabc@gmail.com Co-developed-by: Nan Li Signed-off-by: Nan Li Signed-off-by: Yuqi Xu Reviewed-by: Ren Wei Reviewed-by: Ilya Maximets Link: https://patch.msgid.link/288fbd5459d92b9dd0dcc6faf625f04819161ff3.1787280296.git.xuyuqiabc@gmail.com Signed-off-by: Jakub Kicinski [ 7.0+ uses kmalloc_obj[s] while older versions use kmalloc[_array] ] Signed-off-by: Ilya Maximets Signed-off-by: Sasha Levin

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

2026-09-14T11:30:56+00:00

[ Upstream commit 6bb0dcb3d321c14be7ca33b71a149034d6a2cde8 ] 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 Signed-off-by: Ilya Maximets Signed-off-by: Sasha Levin

openvswitch: fix GSO userspace truncation underflow

2026-08-03T09:17:27+00:00

commit 4032f8ed10fcb84d41c508dfb04be96589f78dfe upstream. OVS_ACTION_ATTR_TRUNC currently stores a delta from the original skb length in OVS_CB(skb)->cutlen. When a later userspace action segments a GSO skb, queue_gso_packets() reuses that delta for each smaller segment. A segment can then reach queue_userspace_packet() with cutlen greater than skb->len, underflowing the length passed to skb_zerocopy(). Store the maximum preserved length instead and bound each consumer against the current skb length. Use U32_MAX as the no-truncation sentinel so the value remains valid if skb geometry changes before a consumer handles it. Fixes: f2a4d086ed4c ("openvswitch: Add packet truncation support.") Cc: stable@vger.kernel.org Assisted-by: Codex:gpt-5.5 Signed-off-by: Kyle Zeng Reviewed-by: Ilya Maximets Reviewed-by: Aaron Conole Link: https://patch.msgid.link/20260707221635.27489-1-kylebot@openai.com Signed-off-by: Paolo Abeni Signed-off-by: Greg Kroah-Hartman

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

2025-03-22T19:54:13+00:00

[ Upstream commit 1063ae07383c0ddc5bcce170260c143825846b03 ] 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 Signed-off-by: Sasha Levin

openvswitch: switch to per-action label counting in conntrack

2024-08-16T02:05:19+00:00

Similar to commit 70f06c115bcc ("sched: act_ct: switch to per-action label counting"), we should also switch to per-action label counting in openvswitch conntrack, as Florian suggested. The difference is that nf_connlabels_get() is called unconditionally when creating an ct action in ovs_ct_copy_action(). As with these flows: table=0,ip,actions=ct(commit,table=1) table=1,ip,actions=ct(commit,exec(set_field:0xac->ct_label),table=2) it needs to make sure the label ext is created in the 1st flow before the ct is committed in ovs_ct_commit(). Otherwise, the warning in nf_ct_ext_add() when creating the label ext in the 2nd flow will be triggered: WARN_ON(nf_ct_is_confirmed(ct)); Signed-off-by: Xin Long Reviewed-by: Aaron Conole Acked-by: Florian Westphal Link: https://patch.msgid.link/6b9347d5c1a0b364e88d900b29a616c3f8e5b1ca.1723483073.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski

net: openvswitch: store sampling probability in cb.

2024-07-06T00:45:47+00:00

When a packet sample is observed, the sampling rate that was used is important to estimate the real frequency of such event. Store the probability of the parent sample action in the skb's cb area and use it in psample action to pass it down to psample module. Reviewed-by: Aaron Conole Acked-by: Eelco Chaudron Reviewed-by: Ilya Maximets Signed-off-by: Adrian Moreno Link: https://patch.msgid.link/20240704085710.353845-7-amorenoz@redhat.com Signed-off-by: Jakub Kicinski

net/sched: Enable tc skb ext allocation on chain miss only when needed

2022-02-05T10:12:53+00:00

Currently tc skb extension is used to send miss info from tc to ovs datapath module, and driver to tc. For the tc to ovs miss it is currently always allocated even if it will not be used by ovs datapath (as it depends on a requested feature). Export the static key which is used by openvswitch module to guard this code path as well, so it will be skipped if ovs datapath doesn't need it. Enable this code path once ovs datapath needs it. Signed-off-by: Paul Blakey Reviewed-by: Jamal Hadi Salim Signed-off-by: David S. Miller

openvswitch: Introduce per-cpu upcall dispatch

2021-07-16T18:06:33+00:00

The Open vSwitch kernel module uses the upcall mechanism to send packets from kernel space to user space when it misses in the kernel space flow table. The upcall sends packets via a Netlink socket. Currently, a Netlink socket is created for every vport. In this way, there is a 1:1 mapping between a vport and a Netlink socket. When a packet is received by a vport, if it needs to be sent to user space, it is sent via the corresponding Netlink socket. This mechanism, with various iterations of the corresponding user space code, has seen some limitations and issues: * On systems with a large number of vports, there is a correspondingly large number of Netlink sockets which can limit scaling. (https://bugzilla.redhat.com/show_bug.cgi?id=1526306) * Packet reordering on upcalls. (https://bugzilla.redhat.com/show_bug.cgi?id=1844576) * A thundering herd issue. (https://bugzilla.redhat.com/show_bug.cgi?id=1834444) This patch introduces an alternative, feature-negotiated, upcall mode using a per-cpu dispatch rather than a per-vport dispatch. In this mode, the Netlink socket to be used for the upcall is selected based on the CPU of the thread that is executing the upcall. In this way, it resolves the issues above as: a) The number of Netlink sockets scales with the number of CPUs rather than the number of vports. b) Ordering per-flow is maintained as packets are distributed to CPUs based on mechanisms such as RSS and flows are distributed to a single user space thread. c) Packets from a flow can only wake up one user space thread. The corresponding user space code can be found at: https://mail.openvswitch.org/pipermail/ovs-dev/2021-July/385139.html Bugzilla: https://bugzilla.redhat.com/1844576 Signed-off-by: Mark Gray Acked-by: Flavio Leitner Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

net: openvswitch: add masks cache hit counter

2020-08-03T22:17:48+00:00

Add a counter that counts the number of masks cache hits, and export it through the megaflow netlink statistics. Reviewed-by: Paolo Abeni Reviewed-by: Tonghao Zhang Signed-off-by: Eelco Chaudron Signed-off-by: David S. Miller

net: openvswitch: fixes potential deadlock in dp cleanup code

2020-07-24T23:58:38+00:00

The previous patch introduced a deadlock, this patch fixes it by making sure the work is canceled without holding the global ovs lock. This is done by moving the reorder processing one layer up to the netns level. Fixes: eac87c413bf9 ("net: openvswitch: reorder masks array based on usage") Reported-by: syzbot+2c4ff3614695f75ce26c@syzkaller.appspotmail.com Reported-by: syzbot+bad6507e5db05017b008@syzkaller.appspotmail.com Reviewed-by: Paolo Signed-off-by: Eelco Chaudron Signed-off-by: David S. Miller