linux-stable.git/net/openvswitch, branch v6.12.97 Linux kernel stable tree net: openvswitch: reject oversized nested action attrs 2026-07-24T14:11:46+00:00 Asim Viladi Oglu Manizada manizada@pm.me 2026-07-06T09:44:10+00:00 f1efff8858403191361a01269c6fe8dd7f55a385 commit 3f1f755366687d051174739fb99f7d560202f60b upstream. Open vSwitch stores generated flow actions as nlattrs, whose nla_len field is u16. Commit a1e64addf3ff ("net: openvswitch: remove misbehaving actions length check") allowed the total sw_flow_actions stream to grow beyond 64 KiB, which is valid, but also removed the last guard preventing a generated nested action attribute from exceeding U16_MAX. An oversized generated container can thus be closed with a truncated nla_len. A later dump or teardown then walks a structurally different stream than the one that was validated. In particular, an oversized nested CLONE/CT action may cause subsequent bytes in the generated stream to be interpreted as independent actions. Keep the larger total-action-stream behavior, but make nested action close reject generated containers that do not fit in nla_len, and return the error through all callers. For recursive SAMPLE, CLONE, DEC_TTL, and CHECK_PKT_LEN builders, trim resource-owning action-list tails in reverse construction order before discarding failed wrappers, so resources copied into the rejected tails are released before the wrappers are removed. Most failed outer wrappers are discarded by truncating actions_len after child resources have been released. CHECK_PKT_LEN also trims its parent after branch resources are gone. SET/TUNNEL close failures unwind their known tun_dst ownership directly, and SET_TO_MASKED has no external ownership and truncates on close failure. Fixes: a1e64addf3ff ("net: openvswitch: remove misbehaving actions length check") Cc: stable@vger.kernel.org Assisted-by: avom-custom-harness:gpt-5.5-qwen3.6-mod-mix Signed-off-by: Asim Viladi Oglu Manizada <manizada@pm.me> Reviewed-by: Eelco Chaudron <echaudro@redhat.com> Reviewed-by: Aaron Conole <aconole@redhat.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260706094336.38639-1-manizada@pm.me Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3f1f755366687d051174739fb99f7d560202f60b upstream.

Open vSwitch stores generated flow actions as nlattrs, whose nla_len
field is u16. Commit a1e64addf3ff ("net: openvswitch: remove
misbehaving actions length check") allowed the total sw_flow_actions
stream to grow beyond 64 KiB, which is valid, but also removed the last
guard preventing a generated nested action attribute from exceeding
U16_MAX.

An oversized generated container can thus be closed with a truncated
nla_len. A later dump or teardown then walks a structurally different
stream than the one that was validated. In particular, an oversized
nested CLONE/CT action may cause subsequent bytes in the generated
stream to be interpreted as independent actions.

Keep the larger total-action-stream behavior, but make nested action
close reject generated containers that do not fit in nla_len, and return
the error through all callers. For recursive SAMPLE, CLONE, DEC_TTL, and
CHECK_PKT_LEN builders, trim resource-owning action-list tails in reverse
construction order before discarding failed wrappers, so resources copied
into the rejected tails are released before the wrappers are removed.

Most failed outer wrappers are discarded by truncating actions_len after
child resources have been released. CHECK_PKT_LEN also trims its parent
after branch resources are gone. SET/TUNNEL close failures unwind their
known tun_dst ownership directly, and SET_TO_MASKED has no external
ownership and truncates on close failure.

Fixes: a1e64addf3ff ("net: openvswitch: remove misbehaving actions length check")
Cc: stable@vger.kernel.org
Assisted-by: avom-custom-harness:gpt-5.5-qwen3.6-mod-mix
Signed-off-by: Asim Viladi Oglu Manizada <manizada@pm.me>
Reviewed-by: Eelco Chaudron <echaudro@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260706094336.38639-1-manizada@pm.me
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
netfilter: nf_conncount: callers must hold rcu read lock 2026-07-24T14:11:02+00:00 Florian Westphal fw@strlen.de 2026-06-05T13:11:19+00:00 0bf7be751e419a60f040e9de03985148a73e5891 [ Upstream commit 64d7d5abe2160bba369b4a8f06bdf5630573bab0 ] rcu_derefence_raw() should not have been used here, it concealed this bug. Its used because struct rb_node lacks __rcu annotated pointers, so plain rcu_derefence causes sparse warnings. The major tradeoff is that rcu_derefence_raw() doesn't warn when the caller isn't in a rcu read section. Extend the rcu read lock scope accordingly and cause sparse warnings, those warnings are the lesser evil. Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit") Closes: https://sashiko.dev/#/patchset/20260603230610.7900-1-fw%40strlen.de Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 64d7d5abe2160bba369b4a8f06bdf5630573bab0 ]

rcu_derefence_raw() should not have been used here, it concealed this bug.
Its used because struct rb_node lacks __rcu annotated pointers, so plain
rcu_derefence causes sparse warnings.

The major tradeoff is that rcu_derefence_raw() doesn't warn when the caller
isn't in a rcu read section.

Extend the rcu read lock scope accordingly and cause sparse warnings,
those warnings are the lesser evil.

Fixes: 11efd5cb04a1 ("openvswitch: Support conntrack zone limit")
Closes: https://sashiko.dev/#/patchset/20260603230610.7900-1-fw%40strlen.de
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: openvswitch: fix possible kfree_skb of ERR_PTR 2026-06-19T11:42:24+00:00 Adrian Moreno amorenoz@redhat.com 2026-06-04T12:19:46+00:00 e3d509a1b71396e1452060dbf84a805fd1c3c549 [ Upstream commit ee30dd2909d8b98619f4341c70ec8dc8e155ab02 ] After the patch in the "Fixes" tag, the allocation of the "reply" skb can happen either before or after locking the ovs_mutex. However, error cleanups still follow the classical reversed order, assuming "reply" is allocated before locking: it is freed after unlocking. If "reply" allocation happens after locking the mutex and it fails, "reply" is left with an ERR_PTR, and execution jumps to the correspondent cleanup stage which will try to free an invalid pointer. Fix this by setting the pointer to NULL after having saved its error value. Fixes: 893f139b9a6c ("openvswitch: Minimize ovs_flow_cmd_new|set critical sections.") Signed-off-by: Adrian Moreno <amorenoz@redhat.com> Reviewed-by: Aaron Conole <aconole@redhat.com> Acked-by: Eelco Chaudron <echaudro@redhat.com> Link: https://patch.msgid.link/20260604121946.942164-1-amorenoz@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ee30dd2909d8b98619f4341c70ec8dc8e155ab02 ]

After the patch in the "Fixes" tag, the allocation of the "reply" skb
can happen either before or after locking the ovs_mutex.

However, error cleanups still follow the classical reversed order,
assuming "reply" is allocated before locking: it is freed after unlocking.

If "reply" allocation happens after locking the mutex and it fails,
"reply" is left with an ERR_PTR, and execution jumps to the correspondent
cleanup stage which will try to free an invalid pointer.

Fix this by setting the pointer to NULL after having saved its error
value.

Fixes: 893f139b9a6c ("openvswitch: Minimize ovs_flow_cmd_new|set critical sections.")
Signed-off-by: Adrian Moreno <amorenoz@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Link: https://patch.msgid.link/20260604121946.942164-1-amorenoz@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
openvswitch: cap upcall PID array size and pre-size vport replies 2026-05-23T11:04:49+00:00 Weiming Shi bestswngs@gmail.com 2026-04-16T02:46:54+00:00 f99ac36b5d7c719d08a69fcdecce40f78a874e15 [ Upstream commit 2091c6aa0df6aba47deb5c8ab232b1cb60af3519 ] The vport netlink reply helpers allocate a fixed-size skb with nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID array via ovs_vport_get_upcall_portids(). Since ovs_vport_set_upcall_portids() accepts any non-zero multiple of sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID array large enough to overflow the reply buffer, causing nla_put() to fail with -EMSGSIZE and hitting BUG_ON(err < 0). On systems with unprivileged user namespaces enabled (e.g., Ubuntu default), this is reachable via unshare -Urn since OVS vport mutation operations use GENL_UNS_ADMIN_PERM. kernel BUG at net/openvswitch/datapath.c:2414! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1 RIP: 0010:ovs_vport_cmd_set+0x34c/0x400 Call Trace: <TASK> genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116) genl_rcv_msg (net/netlink/genetlink.c:1194) netlink_rcv_skb (net/netlink/af_netlink.c:2550) genl_rcv (net/netlink/genetlink.c:1219) netlink_unicast (net/netlink/af_netlink.c:1344) netlink_sendmsg (net/netlink/af_netlink.c:1894) __sys_sendto (net/socket.c:2206) __x64_sys_sendto (net/socket.c:2209) do_syscall_64 (arch/x86/entry/syscall_64.c:63) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) </TASK> Kernel panic - not syncing: Fatal exception Reject attempts to set more PIDs than nr_cpu_ids in ovs_vport_set_upcall_portids(), and pre-compute the worst-case reply size in ovs_vport_cmd_msg_size() based on that bound, similar to the existing ovs_dp_cmd_msg_size(). nr_cpu_ids matches the cap already used by the per-CPU dispatch configuration on the datapath side (ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the two sides stay consistent. Fixes: 5cd667b0a456 ("openvswitch: Allow each vport to have an array of 'port_id's.") Reported-by: Xiang Mei <xmei5@asu.edu> Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260416024653.153456-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 2091c6aa0df6aba47deb5c8ab232b1cb60af3519 ]

The vport netlink reply helpers allocate a fixed-size skb with
nlmsg_new(NLMSG_DEFAULT_SIZE, ...) but serialize the full upcall PID
array via ovs_vport_get_upcall_portids().  Since
ovs_vport_set_upcall_portids() accepts any non-zero multiple of
sizeof(u32) with no upper bound, a CAP_NET_ADMIN user can install a PID
array large enough to overflow the reply buffer, causing nla_put() to
fail with -EMSGSIZE and hitting BUG_ON(err < 0).  On systems with
unprivileged user namespaces enabled (e.g., Ubuntu default), this is
reachable via unshare -Urn since OVS vport mutation operations use
GENL_UNS_ADMIN_PERM.

 kernel BUG at net/openvswitch/datapath.c:2414!
 Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI
 CPU: 1 UID: 0 PID: 65 Comm: poc Not tainted 7.0.0-rc7-00195-geb216e422044 #1
 RIP: 0010:ovs_vport_cmd_set+0x34c/0x400
 Call Trace:
  <TASK>
  genl_family_rcv_msg_doit (net/netlink/genetlink.c:1116)
  genl_rcv_msg (net/netlink/genetlink.c:1194)
  netlink_rcv_skb (net/netlink/af_netlink.c:2550)
  genl_rcv (net/netlink/genetlink.c:1219)
  netlink_unicast (net/netlink/af_netlink.c:1344)
  netlink_sendmsg (net/netlink/af_netlink.c:1894)
  __sys_sendto (net/socket.c:2206)
  __x64_sys_sendto (net/socket.c:2209)
  do_syscall_64 (arch/x86/entry/syscall_64.c:63)
  entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130)
  </TASK>
 Kernel panic - not syncing: Fatal exception

Reject attempts to set more PIDs than nr_cpu_ids in
ovs_vport_set_upcall_portids(), and pre-compute the worst-case reply
size in ovs_vport_cmd_msg_size() based on that bound, similar to the
existing ovs_dp_cmd_msg_size().  nr_cpu_ids matches the cap already
used by the per-CPU dispatch configuration on the datapath side
(ovs_dp_cmd_fill_info() serialises at most nr_cpu_ids PIDs), so the
two sides stay consistent.

Fixes: 5cd667b0a456 ("openvswitch: Allow each vport to have an array of 'port_id's.")
Reported-by: Xiang Mei <xmei5@asu.edu>
Assisted-by: Claude:claude-opus-4-6
Signed-off-by: Weiming Shi <bestswngs@gmail.com>
Reviewed-by: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260416024653.153456-2-bestswngs@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
openvswitch: vport: fix self-deadlock on release of tunnel ports 2026-05-14T13:29:25+00:00 Ilya Maximets i.maximets@ovn.org 2026-04-30T23:38:37+00:00 6522d59fb7de55ce0f0f285d962243ddffebb01f commit aa69918bd418e700309fdd08509dba324fb24296 upstream. vports are used concurrently and protected by RCU, so netdev_put() must happen after the RCU grace period. So, either in an RCU call or after the synchronize_net(). The rtnl_delete_link() must happen under RTNL and so can't be executed in RCU context. Calling synchronize_net() while holding RTNL is not a good idea for performance and system stability under load in general, so calling netdev_put() in RCU call is the right solution here. However, when the device is deleted, rtnl_unlock() will call netdev_run_todo() and block until all the references are gone. In the current code this means that we never reach the call_rcu() and the vport is never freed and the reference is never released, causing a self-deadlock on device removal. Fix that by moving the rcu_call() before the rtnl_unlock(), so the scheduled RCU callback will be executed when synchronize_net() is called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself is already released. Fixes: 6931d21f87bc ("openvswitch: defer tunnel netdev_put to RCU release") Cc: stable@vger.kernel.org Acked-by: Eelco Chaudron <echaudro@redhat.com> Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Acked-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/20260430233848.440994-2-i.maximets@ovn.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit aa69918bd418e700309fdd08509dba324fb24296 upstream.

vports are used concurrently and protected by RCU, so netdev_put()
must happen after the RCU grace period.  So, either in an RCU call or
after the synchronize_net().  The rtnl_delete_link() must happen under
RTNL and so can't be executed in RCU context.  Calling synchronize_net()
while holding RTNL is not a good idea for performance and system
stability under load in general, so calling netdev_put() in RCU call
is the right solution here.

However,
when the device is deleted, rtnl_unlock() will call netdev_run_todo()
and block until all the references are gone.  In the current code this
means that we never reach the call_rcu() and the vport is never freed
and the reference is never released, causing a self-deadlock on device
removal.

Fix that by moving the rcu_call() before the rtnl_unlock(), so the
scheduled RCU callback will be executed when synchronize_net() is
called from the rtnl_unlock()->netdev_run_todo() while the RTNL itself
is already released.

Fixes: 6931d21f87bc ("openvswitch: defer tunnel netdev_put to RCU release")
Cc: stable@vger.kernel.org
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20260430233848.440994-2-i.maximets@ovn.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
openvswitch: validate MPLS set/set_masked payload length 2026-04-02T11:09:33+00:00 Yang Yang n05ec@lzu.edu.cn 2026-03-19T08:02:27+00:00 98de18d327ef8cbbb704980e359e4872d8c28997 [ Upstream commit 546b68ac893595877ffbd7751e5c55fd1c43ede6 ] validate_set() accepted OVS_KEY_ATTR_MPLS as variable-sized payload for SET/SET_MASKED actions. In action handling, OVS expects fixed-size MPLS key data (struct ovs_key_mpls). Use the already normalized key_len (masked case included) and reject non-matching MPLS action key sizes. Reject invalid MPLS action payload lengths early. Fixes: fbdcdd78da7c ("Change in Openvswitch to support MPLS label depth of 3 in ingress direction") 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: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260319080228.3423307-1-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 546b68ac893595877ffbd7751e5c55fd1c43ede6 ]

validate_set() accepted OVS_KEY_ATTR_MPLS as variable-sized payload for
SET/SET_MASKED actions. In action handling, OVS expects fixed-size
MPLS key data (struct ovs_key_mpls).

Use the already normalized key_len (masked case included) and reject
non-matching MPLS action key sizes.

Reject invalid MPLS action payload lengths early.

Fixes: fbdcdd78da7c ("Change in Openvswitch to support MPLS label depth of 3 in ingress direction")
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: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260319080228.3423307-1-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
openvswitch: defer tunnel netdev_put to RCU release 2026-04-02T11:09:32+00:00 Yang Yang n05ec@lzu.edu.cn 2026-03-19T07:42:41+00:00 bbe7bd722bfaea36aab3da6cc60fb4a05c644643 [ Upstream commit 6931d21f87bc6d657f145798fad0bf077b82486c ] ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already detached the device. Dropping the netdev reference in destroy can race with concurrent readers that still observe vport->dev. Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let vport_netdev_free() drop the reference from the RCU callback, matching the non-tunnel destroy path and avoiding additional synchronization under RTNL. Fixes: a9020fde67a6 ("openvswitch: Move tunnel destroy function to oppenvswitch module.") 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: Ilya Maximets <i.maximets@ovn.org> Link: https://patch.msgid.link/20260319074241.3405262-1-n05ec@lzu.edu.cn Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 6931d21f87bc6d657f145798fad0bf077b82486c ]

ovs_netdev_tunnel_destroy() may run after NETDEV_UNREGISTER already
detached the device. Dropping the netdev reference in destroy can race
with concurrent readers that still observe vport->dev.

Do not release vport->dev in ovs_netdev_tunnel_destroy(). Instead, let
vport_netdev_free() drop the reference from the RCU callback, matching
the non-tunnel destroy path and avoiding additional synchronization
under RTNL.

Fixes: a9020fde67a6 ("openvswitch: Move tunnel destroy function to oppenvswitch module.")
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: Ilya Maximets <i.maximets@ovn.org>
Link: https://patch.msgid.link/20260319074241.3405262-1-n05ec@lzu.edu.cn
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: openvswitch: Avoid releasing netdev before teardown completes 2026-04-02T11:09:32+00:00 Toke Høiland-Jørgensen toke@redhat.com 2026-03-18T15:55:51+00:00 43579baa17270aa51f93eb09b6e4af6e047b7f6e [ Upstream commit 7c770dadfda5cbbde6aa3c4363ed513f1d212bf8 ] The patch cited in the Fixes tag below changed the teardown code for OVS ports to no longer unconditionally take the RTNL. After this change, the netdev_destroy() callback can proceed immediately to the call_rcu() invocation if the IFF_OVS_DATAPATH flag is already cleared on the netdev. The ovs_netdev_detach_dev() function clears the flag before completing the unregistration, and if it gets preempted after clearing the flag (as can happen on an -rt kernel), netdev_destroy() can complete and the device can be freed before the unregistration completes. This leads to a splat like: [ 998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI [ 998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT [ 998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025 [ 998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0 [ 998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90 [ 998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246 [ 998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000 [ 998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05 [ 998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000 [ 998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006 [ 998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000 [ 998.393931] FS: 00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000 [ 998.393936] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0 [ 998.393944] PKRU: 55555554 [ 998.393946] Call Trace: [ 998.393949] <TASK> [ 998.393952] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393961] ? show_trace_log_lvl+0x1b0/0x2f0 [ 998.393975] ? dp_device_event+0x41/0x80 [openvswitch] [ 998.394009] ? __die_body.cold+0x8/0x12 [ 998.394016] ? die_addr+0x3c/0x60 [ 998.394027] ? exc_general_protection+0x16d/0x390 [ 998.394042] ? asm_exc_general_protection+0x26/0x30 [ 998.394058] ? dev_set_promiscuity+0x8d/0xa0 [ 998.394066] ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch] [ 998.394092] dp_device_event+0x41/0x80 [openvswitch] [ 998.394102] notifier_call_chain+0x5a/0xd0 [ 998.394106] unregister_netdevice_many_notify+0x51b/0xa60 [ 998.394110] rtnl_dellink+0x169/0x3e0 [ 998.394121] ? rt_mutex_slowlock.constprop.0+0x95/0xd0 [ 998.394125] rtnetlink_rcv_msg+0x142/0x3f0 [ 998.394128] ? avc_has_perm_noaudit+0x69/0xf0 [ 998.394130] ? __pfx_rtnetlink_rcv_msg+0x10/0x10 [ 998.394132] netlink_rcv_skb+0x50/0x100 [ 998.394138] netlink_unicast+0x292/0x3f0 [ 998.394141] netlink_sendmsg+0x21b/0x470 [ 998.394145] ____sys_sendmsg+0x39d/0x3d0 [ 998.394149] ___sys_sendmsg+0x9a/0xe0 [ 998.394156] __sys_sendmsg+0x7a/0xd0 [ 998.394160] do_syscall_64+0x7f/0x170 [ 998.394162] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ 998.394165] RIP: 0033:0x7fad61bf4724 [ 998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89 [ 998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e [ 998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724 [ 998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003 [ 998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f [ 998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2f8380 [ 998.394196] R13: 0000000069b233d7 R14: 000055df0a256040 R15: 0000000000000000 [ 998.394200] </TASK> To fix this, reorder the operations in ovs_netdev_detach_dev() to only clear the flag after completing the other operations, and introduce an smp_wmb() to make the ordering requirement explicit. The smp_wmb() is paired with a full smp_mb() in netdev_destroy() to make sure the call_rcu() invocation does not happen before the unregister operations are visible. Reported-by: Minxi Hou <mhou@redhat.com> Tested-by: Minxi Hou <mhou@redhat.com> Fixes: 549822767630 ("net: openvswitch: Avoid needlessly taking the RTNL on vport destroy") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20260318155554.1133405-1-toke@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 7c770dadfda5cbbde6aa3c4363ed513f1d212bf8 ]

The patch cited in the Fixes tag below changed the teardown code for
OVS ports to no longer unconditionally take the RTNL. After this change,
the netdev_destroy() callback can proceed immediately to the call_rcu()
invocation if the IFF_OVS_DATAPATH flag is already cleared on the
netdev.

The ovs_netdev_detach_dev() function clears the flag before completing
the unregistration, and if it gets preempted after clearing the flag (as
can happen on an -rt kernel), netdev_destroy() can complete and the
device can be freed before the unregistration completes. This leads to a
splat like:

[  998.393867] Oops: general protection fault, probably for non-canonical address 0xff00000001000239: 0000 [#1] SMP PTI
[  998.393877] CPU: 42 UID: 0 PID: 55177 Comm: ip Kdump: loaded Not tainted 6.12.0-211.1.1.el10_2.x86_64+rt #1 PREEMPT_RT
[  998.393886] Hardware name: Dell Inc. PowerEdge R740/0JMK61, BIOS 2.24.0 03/27/2025
[  998.393889] RIP: 0010:dev_set_promiscuity+0x8d/0xa0
[  998.393901] Code: 00 00 75 d8 48 8b 53 08 48 83 ba b0 02 00 00 00 75 ca 48 83 c4 08 5b c3 cc cc cc cc 48 83 bf 48 09 00 00 00 75 91 48 8b 47 08 <48> 83 b8 b0 02 00 00 00 74 97 eb 81 0f 1f 80 00 00 00 00 90 90 90
[  998.393906] RSP: 0018:ffffce5864a5f6a0 EFLAGS: 00010246
[  998.393912] RAX: ff00000000ffff89 RBX: ffff894d0adf5a05 RCX: 0000000000000000
[  998.393917] RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff894d0adf5a05
[  998.393921] RBP: ffff894d19252000 R08: ffff894d19252000 R09: 0000000000000000
[  998.393924] R10: ffff894d19252000 R11: ffff894d192521b8 R12: 0000000000000006
[  998.393927] R13: ffffce5864a5f738 R14: 00000000ffffffe2 R15: 0000000000000000
[  998.393931] FS:  00007fad61971800(0000) GS:ffff894cc0140000(0000) knlGS:0000000000000000
[  998.393936] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  998.393940] CR2: 000055df0a2a6e40 CR3: 000000011c7fe003 CR4: 00000000007726f0
[  998.393944] PKRU: 55555554
[  998.393946] Call Trace:
[  998.393949]  <TASK>
[  998.393952]  ? show_trace_log_lvl+0x1b0/0x2f0
[  998.393961]  ? show_trace_log_lvl+0x1b0/0x2f0
[  998.393975]  ? dp_device_event+0x41/0x80 [openvswitch]
[  998.394009]  ? __die_body.cold+0x8/0x12
[  998.394016]  ? die_addr+0x3c/0x60
[  998.394027]  ? exc_general_protection+0x16d/0x390
[  998.394042]  ? asm_exc_general_protection+0x26/0x30
[  998.394058]  ? dev_set_promiscuity+0x8d/0xa0
[  998.394066]  ? ovs_netdev_detach_dev+0x3a/0x80 [openvswitch]
[  998.394092]  dp_device_event+0x41/0x80 [openvswitch]
[  998.394102]  notifier_call_chain+0x5a/0xd0
[  998.394106]  unregister_netdevice_many_notify+0x51b/0xa60
[  998.394110]  rtnl_dellink+0x169/0x3e0
[  998.394121]  ? rt_mutex_slowlock.constprop.0+0x95/0xd0
[  998.394125]  rtnetlink_rcv_msg+0x142/0x3f0
[  998.394128]  ? avc_has_perm_noaudit+0x69/0xf0
[  998.394130]  ? __pfx_rtnetlink_rcv_msg+0x10/0x10
[  998.394132]  netlink_rcv_skb+0x50/0x100
[  998.394138]  netlink_unicast+0x292/0x3f0
[  998.394141]  netlink_sendmsg+0x21b/0x470
[  998.394145]  ____sys_sendmsg+0x39d/0x3d0
[  998.394149]  ___sys_sendmsg+0x9a/0xe0
[  998.394156]  __sys_sendmsg+0x7a/0xd0
[  998.394160]  do_syscall_64+0x7f/0x170
[  998.394162]  entry_SYSCALL_64_after_hwframe+0x76/0x7e
[  998.394165] RIP: 0033:0x7fad61bf4724
[  998.394188] Code: 89 02 b8 ff ff ff ff eb bb 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 f3 0f 1e fa 80 3d c5 e9 0c 00 00 74 13 b8 2e 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89
[  998.394189] RSP: 002b:00007ffd7e2f7cb8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
[  998.394191] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fad61bf4724
[  998.394193] RDX: 0000000000000000 RSI: 00007ffd7e2f7d20 RDI: 0000000000000003
[  998.394194] RBP: 00007ffd7e2f7d90 R08: 0000000000000010 R09: 000000000000003f
[  998.394195] R10: 000055df11558010 R11: 0000000000000202 R12: 00007ffd7e2f8380
[  998.394196] R13: 0000000069b233d7 R14: 000055df0a256040 R15: 0000000000000000
[  998.394200]  </TASK>

To fix this, reorder the operations in ovs_netdev_detach_dev() to only
clear the flag after completing the other operations, and introduce an
smp_wmb() to make the ordering requirement explicit. The smp_wmb() is
paired with a full smp_mb() in netdev_destroy() to make sure the
call_rcu() invocation does not happen before the unregister operations
are visible.

Reported-by: Minxi Hou <mhou@redhat.com>
Tested-by: Minxi Hou <mhou@redhat.com>
Fixes: 549822767630 ("net: openvswitch: Avoid needlessly taking the RTNL on vport destroy")
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Link: https://patch.msgid.link/20260318155554.1133405-1-toke@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: openvswitch: fix data race in ovs_vport_get_upcall_stats 2026-01-30T09:28:43+00:00 David Yang mmyangfl@gmail.com 2026-01-21T07:29:26+00:00 a8043681b11d74eb8830d1be47fe01baf53b64c0 [ 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 <mmyangfl@gmail.com> Acked-by: Ilya Maximets <i.maximets@ovn.org> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/20260121072932.2360971-1-mmyangfl@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <mmyangfl@gmail.com>
Acked-by: Ilya Maximets <i.maximets@ovn.org>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20260121072932.2360971-1-mmyangfl@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: openvswitch: Avoid needlessly taking the RTNL on vport destroy 2026-01-08T09:14:32+00:00 Toke Høiland-Jørgensen toke@redhat.com 2025-12-11T11:50:05+00:00 5116f61ab11846844585c9082c547c4ccd97ff1a [ 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 <amorenoz@redhat.com> Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Eelco Chaudron <echaudro@redhat.com> Acked-by: Aaron Conole <aconole@redhat.com> Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ 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 <amorenoz@redhat.com>
Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com>
Acked-by: Eelco Chaudron <echaudro@redhat.com>
Acked-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/20251211115006.228876-1-toke@redhat.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>