forked from Minki/linux
56378f3ccb
As pointed out during review, currently the following set of commands
crashes the kernel:
$ ip netns add ns0
$ ip link set swp0 netns ns0
$ ip netns del ns0
WARNING: CPU: 1 PID: 27 at net/core/dev.c:10884 unregister_netdevice_many+0xaa4/0xaec
Workqueue: netns cleanup_net
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : unregister_netdevice_many+0xaa4/0xaec
lr : unregister_netdevice_many+0x700/0xaec
Call trace:
unregister_netdevice_many+0xaa4/0xaec
default_device_exit_batch+0x294/0x340
ops_exit_list+0xac/0xc4
cleanup_net+0x2e4/0x544
process_one_work+0x4ec/0xb40
---[ end trace 0000000000000000 ]---
unregister_netdevice: waiting for swp0 to become free. Usage count = 2
This is because since DSA user ports, since they started populating
dev->rtnl_link_ops in the blamed commit, gained a different treatment
from default_device_exit_net(), which thinks these interfaces can now be
unregistered.
They can't; so set netns_refund = true to restore the behavior prior to
populating dev->rtnl_link_ops.
Fixes: 95f510d0b7 ("net: dsa: allow the DSA master to be seen and changed through rtnetlink")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20220921185428.1767001-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
64 lines
1.3 KiB
C
64 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* Copyright 2022 NXP
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*/
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#include <linux/netdevice.h>
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#include <net/rtnetlink.h>
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#include "dsa_priv.h"
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static const struct nla_policy dsa_policy[IFLA_DSA_MAX + 1] = {
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[IFLA_DSA_MASTER] = { .type = NLA_U32 },
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};
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static int dsa_changelink(struct net_device *dev, struct nlattr *tb[],
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struct nlattr *data[],
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struct netlink_ext_ack *extack)
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{
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int err;
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if (!data)
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return 0;
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if (data[IFLA_DSA_MASTER]) {
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u32 ifindex = nla_get_u32(data[IFLA_DSA_MASTER]);
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struct net_device *master;
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master = __dev_get_by_index(dev_net(dev), ifindex);
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if (!master)
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return -EINVAL;
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err = dsa_slave_change_master(dev, master, extack);
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if (err)
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return err;
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}
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return 0;
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}
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static size_t dsa_get_size(const struct net_device *dev)
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{
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return nla_total_size(sizeof(u32)) + /* IFLA_DSA_MASTER */
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0;
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}
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static int dsa_fill_info(struct sk_buff *skb, const struct net_device *dev)
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{
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struct net_device *master = dsa_slave_to_master(dev);
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if (nla_put_u32(skb, IFLA_DSA_MASTER, master->ifindex))
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return -EMSGSIZE;
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return 0;
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}
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struct rtnl_link_ops dsa_link_ops __read_mostly = {
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.kind = "dsa",
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.priv_size = sizeof(struct dsa_port),
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.maxtype = IFLA_DSA_MAX,
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.policy = dsa_policy,
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.changelink = dsa_changelink,
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.get_size = dsa_get_size,
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.fill_info = dsa_fill_info,
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.netns_refund = true,
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};
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