linux-stable.git/net/openvswitch/datapath.c, branch v6.6.141

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

net: move gso declarations and functions to their own files

2023-06-10T07:11:41+00:00

Move declarations into include/net/gso.h and code into net/core/gso.c

Signed-off-by: Eric Dumazet 
Cc: Stanislav Fomichev 
Reviewed-by: Simon Horman 
Reviewed-by: David Ahern 
Link: https://lore.kernel.org/r/20230608191738.3947077-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: openvswitch: fix upcall counter access before allocation

2023-06-07T11:25:05+00:00

Currently, the per cpu upcall counters are allocated after the vport is
created and inserted into the system. This could lead to the datapath
accessing the counters before they are allocated resulting in a kernel
Oops.

Here is an example:

  PID: 59693    TASK: ffff0005f4f51500  CPU: 0    COMMAND: "ovs-vswitchd"
   #0 [ffff80000a39b5b0] __switch_to at ffffb70f0629f2f4
   #1 [ffff80000a39b5d0] __schedule at ffffb70f0629f5cc
   #2 [ffff80000a39b650] preempt_schedule_common at ffffb70f0629fa60
   #3 [ffff80000a39b670] dynamic_might_resched at ffffb70f0629fb58
   #4 [ffff80000a39b680] mutex_lock_killable at ffffb70f062a1388
   #5 [ffff80000a39b6a0] pcpu_alloc at ffffb70f0594460c
   #6 [ffff80000a39b750] __alloc_percpu_gfp at ffffb70f05944e68
   #7 [ffff80000a39b760] ovs_vport_cmd_new at ffffb70ee6961b90 [openvswitch]
   ...

  PID: 58682    TASK: ffff0005b2f0bf00  CPU: 0    COMMAND: "kworker/0:3"
   #0 [ffff80000a5d2f40] machine_kexec at ffffb70f056a0758
   #1 [ffff80000a5d2f70] __crash_kexec at ffffb70f057e2994
   #2 [ffff80000a5d3100] crash_kexec at ffffb70f057e2ad8
   #3 [ffff80000a5d3120] die at ffffb70f0628234c
   #4 [ffff80000a5d31e0] die_kernel_fault at ffffb70f062828a8
   #5 [ffff80000a5d3210] __do_kernel_fault at ffffb70f056a31f4
   #6 [ffff80000a5d3240] do_bad_area at ffffb70f056a32a4
   #7 [ffff80000a5d3260] do_translation_fault at ffffb70f062a9710
   #8 [ffff80000a5d3270] do_mem_abort at ffffb70f056a2f74
   #9 [ffff80000a5d32a0] el1_abort at ffffb70f06297dac
  #10 [ffff80000a5d32d0] el1h_64_sync_handler at ffffb70f06299b24
  #11 [ffff80000a5d3410] el1h_64_sync at ffffb70f056812dc
  #12 [ffff80000a5d3430] ovs_dp_upcall at ffffb70ee6963c84 [openvswitch]
  #13 [ffff80000a5d3470] ovs_dp_process_packet at ffffb70ee6963fdc [openvswitch]
  #14 [ffff80000a5d34f0] ovs_vport_receive at ffffb70ee6972c78 [openvswitch]
  #15 [ffff80000a5d36f0] netdev_port_receive at ffffb70ee6973948 [openvswitch]
  #16 [ffff80000a5d3720] netdev_frame_hook at ffffb70ee6973a28 [openvswitch]
  #17 [ffff80000a5d3730] __netif_receive_skb_core.constprop.0 at ffffb70f06079f90

We moved the per cpu upcall counter allocation to the existing vport
alloc and free functions to solve this.

Fixes: 95637d91fefd ("net: openvswitch: release vport resources on failure")
Fixes: 1933ea365aa7 ("net: openvswitch: Add support to count upcall packets")
Signed-off-by: Eelco Chaudron 
Reviewed-by: Simon Horman 
Acked-by: Aaron Conole 
Signed-off-by: David S. Miller

net: openvswitch: fix flow memory leak in ovs_flow_cmd_new

2023-02-02T19:32:51+00:00

Syzkaller reports a memory leak of new_flow in ovs_flow_cmd_new() as it is
not freed when an allocation of a key fails.

BUG: memory leak
unreferenced object 0xffff888116668000 (size 632):
  comm "syz-executor231", pid 1090, jiffies 4294844701 (age 18.871s)
  hex dump (first 32 bytes):
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000defa3494>] kmem_cache_zalloc include/linux/slab.h:654 [inline]
    [<00000000defa3494>] ovs_flow_alloc+0x19/0x180 net/openvswitch/flow_table.c:77
    [<00000000c67d8873>] ovs_flow_cmd_new+0x1de/0xd40 net/openvswitch/datapath.c:957
    [<0000000010a539a8>] genl_family_rcv_msg_doit+0x22d/0x330 net/netlink/genetlink.c:739
    [<00000000dff3302d>] genl_family_rcv_msg net/netlink/genetlink.c:783 [inline]
    [<00000000dff3302d>] genl_rcv_msg+0x328/0x590 net/netlink/genetlink.c:800
    [<000000000286dd87>] netlink_rcv_skb+0x153/0x430 net/netlink/af_netlink.c:2515
    [<0000000061fed410>] genl_rcv+0x24/0x40 net/netlink/genetlink.c:811
    [<000000009dc0f111>] netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline]
    [<000000009dc0f111>] netlink_unicast+0x545/0x7f0 net/netlink/af_netlink.c:1339
    [<000000004a5ee816>] netlink_sendmsg+0x8e7/0xde0 net/netlink/af_netlink.c:1934
    [<00000000482b476f>] sock_sendmsg_nosec net/socket.c:651 [inline]
    [<00000000482b476f>] sock_sendmsg+0x152/0x190 net/socket.c:671
    [<00000000698574ba>] ____sys_sendmsg+0x70a/0x870 net/socket.c:2356
    [<00000000d28d9e11>] ___sys_sendmsg+0xf3/0x170 net/socket.c:2410
    [<0000000083ba9120>] __sys_sendmsg+0xe5/0x1b0 net/socket.c:2439
    [<00000000c00628f8>] do_syscall_64+0x30/0x40 arch/x86/entry/common.c:46
    [<000000004abfdcf4>] entry_SYSCALL_64_after_hwframe+0x61/0xc6

To fix this the patch rearranges the goto labels to reflect the order of
object allocations and adds appropriate goto statements on the error
paths.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 68bb10101e6b ("openvswitch: Fix flow lookup to use unmasked key")
Signed-off-by: Fedor Pchelkin 
Signed-off-by: Alexey Khoroshilov 
Acked-by: Eelco Chaudron 
Reviewed-by: Simon Horman 
Link: https://lore.kernel.org/r/20230201210218.361970-1-pchelkin@ispras.ru
Signed-off-by: Jakub Kicinski