kernel/linux.git/net/openvswitch/datapath.c, branch v6.6.152

net: openvswitch: reallocate update replies for mismatched IDs

2026-08-19T16:13:10+00:00

commit 5d1c224dd914579524a183a514c12b95095d12ce upstream. ovs_flow_cmd_new() preallocates the optional reply skb before it takes ovs_mutex and before it knows which existing flow will be updated. That is normally fine because the skb is sized from the request flow identifier. That identifier also becomes the inserted flow's identifier. For updates, however, a request with a UFID may miss the UFID lookup and then fall back to the flow key lookup. That lookup can legitimately find an existing key-identified flow. UFIDs are optional and the flow key is the primary identifier. For echoed replies, ovs_flow_cmd_fill_info() writes the matched flow's identifier, not the request identifier used for the preallocation. A short request UFID can therefore leave too little room for the key identifier. The fill can then fail with -EMSGSIZE and hit the BUG_ON(error < 0) in the update path. Once the update target has been resolved, reallocate the reply skb if the matched flow needs a larger reply than the request identifier allowed. Do this before replacing the actions so the request can still fail cleanly if the rare extra allocation fails. Fixes: 74ed7ab9264c ("openvswitch: Add support for unique flow IDs.") Cc: stable@vger.kernel.org Reported-by: Vega Signed-off-by: Zhiling Zou Reviewed-by: Ilya Maximets Link: https://patch.msgid.link/f7bbd3c30ce81a39156e226b3872d73abed21d2f.1785644623.git.zhilinz@nebusec.ai Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman

openvswitch: fix GSO userspace truncation underflow

2026-08-03T09:15:33+00:00

[ Upstream commit 4032f8ed10fcb84d41c508dfb04be96589f78dfe ] 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 [6.6.y and older don't have OVS_ACTION_ATTR_PSAMPLE] Signed-off-by: Ilya Maximets Signed-off-by: Sasha Levin

net: openvswitch: fix possible kfree_skb of ERR_PTR

2026-06-19T11:39:30+00:00

[ 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 Reviewed-by: Aaron Conole Acked-by: Eelco Chaudron Link: https://patch.msgid.link/20260604121946.942164-1-amorenoz@redhat.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

openvswitch: cap upcall PID array size and pre-size vport replies

2026-05-23T11:03:24+00:00

[ 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: 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) 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 Assisted-by: Claude:claude-opus-4-6 Signed-off-by: Weiming Shi Reviewed-by: Ilya Maximets Link: https://patch.msgid.link/20260416024653.153456-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

openvswitch: use RCU protection in ovs_vport_cmd_fill_info()

2025-02-21T12:57:23+00:00

[ Upstream commit 90b2f49a502fa71090d9f4fe29a2f51fe5dff76d ] ovs_vport_cmd_fill_info() can be called without RTNL or RCU. Use RCU protection and dev_net_rcu() to avoid potential UAF. Fixes: 9354d4520342 ("openvswitch: reliable interface indentification in port dumps") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250207135841.1948589-6-edumazet@google.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: ovs: fix ovs_drop_reasons error

2024-08-29T15:33:50+00:00

[ Upstream commit 57fb67783c4011581882f32e656d738da1f82042 ] There is something wrong with ovs_drop_reasons. ovs_drop_reasons[0] is "OVS_DROP_LAST_ACTION", but OVS_DROP_LAST_ACTION == __OVS_DROP_REASON + 1, which means that ovs_drop_reasons[1] should be "OVS_DROP_LAST_ACTION". And as Adrian tested, without the patch, adding flow to drop packets results in: drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97) origin: software input port ifindex: 8 timestamp: Tue Aug 20 10:19:17 2024 859853461 nsec protocol: 0x800 length: 98 original length: 98 drop reason: OVS_DROP_ACTION_ERROR With the patch, the same results in: drop at: do_execute_actions+0x197/0xb20 [openvsw (0xffffffffc0db6f97) origin: software input port ifindex: 8 timestamp: Tue Aug 20 10:16:13 2024 475856608 nsec protocol: 0x800 length: 98 original length: 98 drop reason: OVS_DROP_LAST_ACTION Fix this by initializing ovs_drop_reasons with index. Fixes: 9d802da40b7c ("net: openvswitch: add last-action drop reason") Signed-off-by: Menglong Dong Tested-by: Adrian Moreno Reviewed-by: Adrian Moreno Link: https://patch.msgid.link/20240821123252.186305-1-dongml2@chinatelecom.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

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

2023-08-18T19:44:56+00:00

Cross-merge networking fixes after downstream PR. Conflicts: drivers/net/ethernet/sfc/tc.c fa165e194997 ("sfc: don't unregister flow_indr if it was never registered") 3bf969e88ada ("sfc: add MAE table machinery for conntrack table") https://lore.kernel.org/all/20230818112159.7430e9b4@canb.auug.org.au/ No adjacent changes. Signed-off-by: Jakub Kicinski

net: openvswitch: reject negative ifindex

2023-08-16T02:07:52+00:00

Recent changes in net-next (commit 759ab1edb56c ("net: store netdevs in an xarray")) refactored the handling of pre-assigned ifindexes and let syzbot surface a latent problem in ovs. ovs does not validate ifindex, making it possible to create netdev ports with negative ifindex values. It's easy to repro with YNL: $ ./cli.py --spec netlink/specs/ovs_datapath.yaml \ --do new \ --json '{"upcall-pid": 1, "name":"my-dp"}' $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' $ ip link show -65536: some-port0: mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether 7a:48:21:ad:0b:fb brd ff:ff:ff:ff:ff:ff ... Validate the inputs. Now the second command correctly returns: $ ./cli.py --spec netlink/specs/ovs_vport.yaml \ --do new \ --json '{"upcall-pid": "00000001", "name": "some-port0", "dp-ifindex":3,"ifindex":4294901760,"type":2}' lib.ynl.NlError: Netlink error: Numerical result out of range nl_len = 108 (92) nl_flags = 0x300 nl_type = 2 error: -34 extack: {'msg': 'integer out of range', 'unknown': [[type:4 len:36] b'\x0c\x00\x02\x00\x00\x00\x00\x00\x00\x00\x00\x00\x0c\x00\x03\x00\xff\xff\xff\x7f\x00\x00\x00\x00\x08\x00\x01\x00\x08\x00\x00\x00'], 'bad-attr': '.ifindex'} Accept 0 since it used to be silently ignored. Fixes: 54c4ef34c4b6 ("openvswitch: allow specifying ifindex of new interfaces") Reported-by: syzbot+7456b5dcf65111553320@syzkaller.appspotmail.com Reviewed-by: Leon Romanovsky Reviewed-by: Aaron Conole Link: https://lore.kernel.org/r/20230814203840.2908710-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

genetlink: remove userhdr from struct genl_info

2023-08-15T21:54:44+00:00

Only three families use info->userhdr today and going forward we discourage using fixed headers in new families. So having the pointer to user header in struct genl_info is an overkill. Compute the header pointer at runtime. Reviewed-by: Johannes Berg Reviewed-by: Jiri Pirko Reviewed-by: Aaron Conole Link: https://lore.kernel.org/r/20230814214723.2924989-4-kuba@kernel.org Signed-off-by: Jakub Kicinski

net: openvswitch: add last-action drop reason

2023-08-14T07:01:06+00:00

Create a new drop reason subsystem for openvswitch and add the first drop reason to represent last-action drops. Last-action drops happen when a flow has an empty action list or there is no action that consumes the packet (output, userspace, recirc, etc). It is the most common way in which OVS drops packets. Implementation-wise, most of these skb-consuming actions already call "consume_skb" internally and return directly from within the do_execute_actions() loop so with minimal changes we can assume that any skb that exits the loop normally is a packet drop. Signed-off-by: Adrian Moreno Signed-off-by: David S. Miller