kernel/linux.git/net/openvswitch/vport-vxlan.c, branch v7.1.6

openvswitch: vport: fix race between tunnel creation and linking

2026-05-05T13:14:33+00:00

When a tunnel vport is created it first creates the tunnel device, e.g., with geneve_dev_create_fb(), then it calls ovs_netdev_link() to take a reference and link it to the device that represents openvswitch datapath. The creation of the device is happening under RTNL, but then RTNL is released and re-acquired to find the device by name. It is technically possible for the tunnel device to be re-named or deleted within that window while RTNL is not held, and some other device created in its place. This will cause a non-tunnel device to be referenced in the vport and tunnel-specific functions used on it, e.g. vxlan_get_options() that directly casts the private netdev data into a struct vxlan_dev causing an invalid memory access: BUG: KASAN: slab-use-after-free in vxlan_get_options+0x323/0x3a0 vxlan_get_options+0x323/0x3a0 ovs_vport_cmd_new+0x6e3/0xd30 Fix that by taking a reference to the just created device before releasing RTNL. This ensures that the device in the vport is always the one that was just created. The search by name is only needed for a standard vport-netdev that links pre-existing devices, so that functionality and device type checks are moved to netdev_create(). It is also awkward that ovs_netdev_link() takes ownership of the vport and destroys it on failure. It doesn't know the type of the port it is dealing with, so we need to pass down the indicator that it's a tunnel, so the link can be properly deleted on failure. It's possible to refactor the logic to make the ovs_netdev_link() do only the linking part and let the callers perform a proper destruction, but it will be much more code for each legacy tunnel port type, so it is not worth it for the bug fix. Fixes: 614732eaa12d ("openvswitch: Use regular VXLAN net_device device") Reported-by: Yuan Tan Reported-by: Yifan Wu Reported-by: Juefei Pu Reported-by: Xin Liu Reported-by: Yang Yang Signed-off-by: Ilya Maximets Acked-by: Eelco Chaudron Link: https://patch.msgid.link/20260430213349.407991-1-i.maximets@ovn.org Signed-off-by: Paolo Abeni

rtnetlink: Honour NLM_F_ECHO flag in rtnl_delete_link

2022-11-01T01:10:21+00:00

This patch use the new helper unregister_netdevice_many_notify() for rtnl_delete_link(), so that the kernel could reply unicast when userspace set NLM_F_ECHO flag to request the new created interface info. At the same time, the parameters of rtnl_delete_link() need to be updated since we need nlmsghdr and portid info. Suggested-by: Guillaume Nault Signed-off-by: Hangbin Liu Reviewed-by: Guillaume Nault Signed-off-by: Jakub Kicinski

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 269

2019-06-05T15:30:29+00:00

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of version 2 of the gnu general public license as published by the free software foundation this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 51 franklin street fifth floor boston ma 02110 1301 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 21 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Alexios Zavras Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190529141334.228102212@linutronix.de Signed-off-by: Greg Kroah-Hartman

netlink: make validation more configurable for future strictness

2019-04-27T21:07:21+00:00

We currently have two levels of strict validation: 1) liberal (default) - undefined (type >= max) & NLA_UNSPEC attributes accepted - attribute length >= expected accepted - garbage at end of message accepted 2) strict (opt-in) - NLA_UNSPEC attributes accepted - attribute length >= expected accepted Split out parsing strictness into four different options: * TRAILING - check that there's no trailing data after parsing attributes (in message or nested) * MAXTYPE - reject attrs > max known type * UNSPEC - reject attributes with NLA_UNSPEC policy entries * STRICT_ATTRS - strictly validate attribute size The default for future things should be *everything*. The current *_strict() is a combination of TRAILING and MAXTYPE, and is renamed to _deprecated_strict(). The current regular parsing has none of this, and is renamed to *_parse_deprecated(). Additionally it allows us to selectively set one of the new flags even on old policies. Notably, the UNSPEC flag could be useful in this case, since it can be arranged (by filling in the policy) to not be an incompatible userspace ABI change, but would then going forward prevent forgetting attribute entries. Similar can apply to the POLICY flag. We end up with the following renames: * nla_parse -> nla_parse_deprecated * nla_parse_strict -> nla_parse_deprecated_strict * nlmsg_parse -> nlmsg_parse_deprecated * nlmsg_parse_strict -> nlmsg_parse_deprecated_strict * nla_parse_nested -> nla_parse_nested_deprecated * nla_validate_nested -> nla_validate_nested_deprecated Using spatch, of course: @@ expression TB, MAX, HEAD, LEN, POL, EXT; @@ -nla_parse(TB, MAX, HEAD, LEN, POL, EXT) +nla_parse_deprecated(TB, MAX, HEAD, LEN, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression NLH, HDRLEN, TB, MAX, POL, EXT; @@ -nlmsg_parse_strict(NLH, HDRLEN, TB, MAX, POL, EXT) +nlmsg_parse_deprecated_strict(NLH, HDRLEN, TB, MAX, POL, EXT) @@ expression TB, MAX, NLA, POL, EXT; @@ -nla_parse_nested(TB, MAX, NLA, POL, EXT) +nla_parse_nested_deprecated(TB, MAX, NLA, POL, EXT) @@ expression START, MAX, POL, EXT; @@ -nla_validate_nested(START, MAX, POL, EXT) +nla_validate_nested_deprecated(START, MAX, POL, EXT) @@ expression NLH, HDRLEN, MAX, POL, EXT; @@ -nlmsg_validate(NLH, HDRLEN, MAX, POL, EXT) +nlmsg_validate_deprecated(NLH, HDRLEN, MAX, POL, EXT) For this patch, don't actually add the strict, non-renamed versions yet so that it breaks compile if I get it wrong. Also, while at it, make nla_validate and nla_parse go down to a common __nla_validate_parse() function to avoid code duplication. Ultimately, this allows us to have very strict validation for every new caller of nla_parse()/nlmsg_parse() etc as re-introduced in the next patch, while existing things will continue to work as is. In effect then, this adds fully strict validation for any new command. Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

netlink: make nla_nest_start() add NLA_F_NESTED flag

2019-04-27T21:03:44+00:00

Even if the NLA_F_NESTED flag was introduced more than 11 years ago, most netlink based interfaces (including recently added ones) are still not setting it in kernel generated messages. Without the flag, message parsers not aware of attribute semantics (e.g. wireshark dissector or libmnl's mnl_nlmsg_fprintf()) cannot recognize nested attributes and won't display the structure of their contents. Unfortunately we cannot just add the flag everywhere as there may be userspace applications which check nlattr::nla_type directly rather than through a helper masking out the flags. Therefore the patch renames nla_nest_start() to nla_nest_start_noflag() and introduces nla_nest_start() as a wrapper adding NLA_F_NESTED. The calls which add NLA_F_NESTED manually are rewritten to use nla_nest_start(). Except for changes in include/net/netlink.h, the patch was generated using this semantic patch: @@ expression E1, E2; @@ -nla_nest_start(E1, E2) +nla_nest_start_noflag(E1, E2) @@ expression E1, E2; @@ -nla_nest_start_noflag(E1, E2 | NLA_F_NESTED) +nla_nest_start(E1, E2) Signed-off-by: Michal Kubecek Acked-by: Jiri Pirko Acked-by: David Ahern Signed-off-by: David S. Miller

net: core: dev: Add extack argument to dev_change_flags()

2018-12-06T21:26:07+00:00

In order to pass extack together with NETDEV_PRE_UP notifications, it's necessary to route the extack to __dev_open() from diverse (possibly indirect) callers. One prominent API through which the notification is invoked is dev_change_flags(). Therefore extend dev_change_flags() with and extra extack argument and update all users. Most of the calls end up just encoding NULL, but several sites (VLAN, ipvlan, VRF, rtnetlink) do have extack available. Since the function declaration line is changed anyway, name the other function arguments to placate checkpatch. Signed-off-by: Petr Machata Acked-by: Jiri Pirko Reviewed-by: Ido Schimmel Reviewed-by: David Ahern Signed-off-by: David S. Miller

vxlan: get rid of redundant vxlan_dev.flags

2017-06-20T17:37:02+00:00

There is no good reason to keep the flags twice in vxlan_dev and vxlan_config. Signed-off-by: Matthias Schiffer Signed-off-by: David S. Miller

netlink: pass extended ACK struct to parsing functions

2017-04-13T17:58:22+00:00

Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

openvswitch: do not ignore netdev errors when creating tunnel vports

2016-08-11T06:13:23+00:00

The creation of a tunnel vport (geneve, gre, vxlan) brings up a corresponding netdev, a multi-step operation which can fail. For example, changing a vxlan vport's netdev state to 'up' binds the vport's socket to a UDP port - if the binding fails (e.g. due to the port being in use), the error is currently ignored giving the appearance that the tunnel vport creation completed successfully. Signed-off-by: Martynas Pumputis Acked-by: Pravin B Shelar Signed-off-by: David S. Miller

lwt: fix rx checksum setting for lwt devices tunneling over ipv6

2016-02-19T20:39:30+00:00

the commit 35e2d1152b22 ("tunnels: Allow IPv6 UDP checksums to be correctly controlled.") changed the default xmit checksum setting for lwt vxlan/geneve ipv6 tunnels, so that now the checksum is not set into external UDP header. This commit changes the rx checksum setting for both lwt vxlan/geneve devices created by openvswitch accordingly, so that lwt over ipv6 tunnel pairs are again able to communicate with default values. Signed-off-by: Paolo Abeni Acked-by: Jiri Benc Acked-by: Jesse Gross Signed-off-by: David S. Miller