diff options
| author | Stanislav Fomichev <sdf@fomichev.me> | 2025-04-04 09:11:22 -0700 |
|---|---|---|
| committer | Jakub Kicinski <kuba@kernel.org> | 2025-04-07 11:13:39 -0700 |
| commit | 04efcee6ef8d0f01eef495db047e7216d6e6e38f (patch) | |
| tree | 513d24326a6ea9ec632d44f907b2651b9709f5cf /net/core/rtnetlink.c | |
| parent | 54f5fafcced113c7d203f6848f4f14840e74e9d1 (diff) | |
net: hold instance lock during NETDEV_CHANGE
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: ad7c7b2172c3 ("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>
Diffstat (limited to 'net/core/rtnetlink.c')
| -rw-r--r-- | net/core/rtnetlink.c | 15 |
1 files changed, 9 insertions, 6 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index c23852835050..d8d03ff87a3b 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -1043,7 +1043,7 @@ int rtnl_put_cacheinfo(struct sk_buff *skb, struct dst_entry *dst, u32 id, } EXPORT_SYMBOL_GPL(rtnl_put_cacheinfo); -void netdev_set_operstate(struct net_device *dev, int newstate) +void netif_set_operstate(struct net_device *dev, int newstate) { unsigned int old = READ_ONCE(dev->operstate); @@ -1052,9 +1052,9 @@ void netdev_set_operstate(struct net_device *dev, int newstate) return; } while (!try_cmpxchg(&dev->operstate, &old, newstate)); - netdev_state_change(dev); + netif_state_change(dev); } -EXPORT_SYMBOL(netdev_set_operstate); +EXPORT_SYMBOL(netif_set_operstate); static void set_operstate(struct net_device *dev, unsigned char transition) { @@ -1080,7 +1080,7 @@ static void set_operstate(struct net_device *dev, unsigned char transition) break; } - netdev_set_operstate(dev, operstate); + netif_set_operstate(dev, operstate); } static unsigned int rtnl_dev_get_flags(const struct net_device *dev) @@ -3396,7 +3396,7 @@ static int do_setlink(const struct sk_buff *skb, struct net_device *dev, errout: if (status & DO_SETLINK_MODIFIED) { if ((status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY) - netdev_state_change(dev); + netif_state_change(dev); if (err < 0) net_warn_ratelimited("A link change request failed with some changes committed already. Interface %s may have been left with an inconsistent configuration, please check.\n", @@ -3676,8 +3676,11 @@ struct net_device *rtnl_create_link(struct net *net, const char *ifname, nla_len(tb[IFLA_BROADCAST])); if (tb[IFLA_TXQLEN]) dev->tx_queue_len = nla_get_u32(tb[IFLA_TXQLEN]); - if (tb[IFLA_OPERSTATE]) + if (tb[IFLA_OPERSTATE]) { + netdev_lock_ops(dev); set_operstate(dev, nla_get_u8(tb[IFLA_OPERSTATE])); + netdev_unlock_ops(dev); + } if (tb[IFLA_LINKMODE]) dev->link_mode = nla_get_u8(tb[IFLA_LINKMODE]); if (tb[IFLA_GROUP]) |