forked from mirrors/linux
04efcee6ef
Cosmin reports an issue with ipv6_add_dev being called from
NETDEV_CHANGE notifier:
[ 3455.008776] ? ipv6_add_dev+0x370/0x620
[ 3455.010097] ipv6_find_idev+0x96/0xe0
[ 3455.010725] addrconf_add_dev+0x1e/0xa0
[ 3455.011382] addrconf_init_auto_addrs+0xb0/0x720
[ 3455.013537] addrconf_notify+0x35f/0x8d0
[ 3455.014214] notifier_call_chain+0x38/0xf0
[ 3455.014903] netdev_state_change+0x65/0x90
[ 3455.015586] linkwatch_do_dev+0x5a/0x70
[ 3455.016238] rtnl_getlink+0x241/0x3e0
[ 3455.019046] rtnetlink_rcv_msg+0x177/0x5e0
Similarly, linkwatch might get to ipv6_add_dev without ops lock:
[ 3456.656261] ? ipv6_add_dev+0x370/0x620
[ 3456.660039] ipv6_find_idev+0x96/0xe0
[ 3456.660445] addrconf_add_dev+0x1e/0xa0
[ 3456.660861] addrconf_init_auto_addrs+0xb0/0x720
[ 3456.661803] addrconf_notify+0x35f/0x8d0
[ 3456.662236] notifier_call_chain+0x38/0xf0
[ 3456.662676] netdev_state_change+0x65/0x90
[ 3456.663112] linkwatch_do_dev+0x5a/0x70
[ 3456.663529] __linkwatch_run_queue+0xeb/0x200
[ 3456.663990] linkwatch_event+0x21/0x30
[ 3456.664399] process_one_work+0x211/0x610
[ 3456.664828] worker_thread+0x1cc/0x380
[ 3456.665691] kthread+0xf4/0x210
Reclassify NETDEV_CHANGE as a notifier that consistently runs under the
instance lock.
Link: https://lore.kernel.org/netdev/aac073de8beec3e531c86c101b274d434741c28e.camel@nvidia.com/
Reported-by: Cosmin Ratiu <cratiu@nvidia.com>
Tested-by: Cosmin Ratiu <cratiu@nvidia.com>
Fixes: ad7c7b2172 ("net: hold netdev instance lock during sysfs operations")
Signed-off-by: Stanislav Fomichev <sdf@fomichev.me>
Link: https://patch.msgid.link/20250404161122.3907628-1-sdf@fomichev.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
120 lines
3 KiB
C
120 lines
3 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
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/* Copyright Amazon.com Inc. or its affiliates. */
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#include <linux/init.h>
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#include <linux/netdevice.h>
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#include <linux/notifier.h>
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#include <linux/rtnetlink.h>
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#include <net/net_namespace.h>
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#include <net/netdev_lock.h>
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#include <net/netns/generic.h>
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int netdev_debug_event(struct notifier_block *nb, unsigned long event,
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void *ptr)
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{
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struct net_device *dev = netdev_notifier_info_to_dev(ptr);
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struct net *net = dev_net(dev);
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enum netdev_cmd cmd = event;
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/* Keep enum and don't add default to trigger -Werror=switch */
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switch (cmd) {
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case NETDEV_REGISTER:
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case NETDEV_UP:
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case NETDEV_CHANGE:
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netdev_ops_assert_locked(dev);
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fallthrough;
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case NETDEV_DOWN:
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case NETDEV_REBOOT:
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case NETDEV_UNREGISTER:
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case NETDEV_CHANGEMTU:
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case NETDEV_CHANGEADDR:
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case NETDEV_PRE_CHANGEADDR:
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case NETDEV_GOING_DOWN:
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case NETDEV_FEAT_CHANGE:
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case NETDEV_BONDING_FAILOVER:
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case NETDEV_PRE_UP:
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case NETDEV_PRE_TYPE_CHANGE:
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case NETDEV_POST_TYPE_CHANGE:
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case NETDEV_POST_INIT:
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case NETDEV_PRE_UNINIT:
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case NETDEV_RELEASE:
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case NETDEV_NOTIFY_PEERS:
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case NETDEV_JOIN:
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case NETDEV_CHANGEUPPER:
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case NETDEV_RESEND_IGMP:
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case NETDEV_PRECHANGEMTU:
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case NETDEV_CHANGEINFODATA:
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case NETDEV_BONDING_INFO:
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case NETDEV_PRECHANGEUPPER:
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case NETDEV_CHANGELOWERSTATE:
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case NETDEV_UDP_TUNNEL_PUSH_INFO:
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case NETDEV_UDP_TUNNEL_DROP_INFO:
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case NETDEV_CHANGE_TX_QUEUE_LEN:
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case NETDEV_CVLAN_FILTER_PUSH_INFO:
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case NETDEV_CVLAN_FILTER_DROP_INFO:
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case NETDEV_SVLAN_FILTER_PUSH_INFO:
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case NETDEV_SVLAN_FILTER_DROP_INFO:
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case NETDEV_OFFLOAD_XSTATS_ENABLE:
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case NETDEV_OFFLOAD_XSTATS_DISABLE:
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case NETDEV_OFFLOAD_XSTATS_REPORT_USED:
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case NETDEV_OFFLOAD_XSTATS_REPORT_DELTA:
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case NETDEV_XDP_FEAT_CHANGE:
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ASSERT_RTNL();
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break;
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case NETDEV_CHANGENAME:
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ASSERT_RTNL_NET(net);
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break;
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}
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return NOTIFY_DONE;
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}
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EXPORT_SYMBOL_NS_GPL(netdev_debug_event, "NETDEV_INTERNAL");
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static int rtnl_net_debug_net_id;
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static int __net_init rtnl_net_debug_net_init(struct net *net)
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{
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struct notifier_block *nb;
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nb = net_generic(net, rtnl_net_debug_net_id);
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nb->notifier_call = netdev_debug_event;
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return register_netdevice_notifier_net(net, nb);
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}
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static void __net_exit rtnl_net_debug_net_exit(struct net *net)
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{
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struct notifier_block *nb;
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nb = net_generic(net, rtnl_net_debug_net_id);
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unregister_netdevice_notifier_net(net, nb);
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}
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static struct pernet_operations rtnl_net_debug_net_ops __net_initdata = {
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.init = rtnl_net_debug_net_init,
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.exit = rtnl_net_debug_net_exit,
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.id = &rtnl_net_debug_net_id,
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.size = sizeof(struct notifier_block),
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};
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static struct notifier_block rtnl_net_debug_block = {
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.notifier_call = netdev_debug_event,
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};
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static int __init rtnl_net_debug_init(void)
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{
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int ret;
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ret = register_pernet_subsys(&rtnl_net_debug_net_ops);
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if (ret)
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return ret;
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ret = register_netdevice_notifier(&rtnl_net_debug_block);
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if (ret)
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unregister_pernet_subsys(&rtnl_net_debug_net_ops);
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return ret;
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}
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subsys_initcall(rtnl_net_debug_init);
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