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| 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/dev_api.c | |
| parent | 54f5fafcced113c7d203f6848f4f14840e74e9d1 (diff) | |
| download | linux-04efcee6ef8d0f01eef495db047e7216d6e6e38f.tar.gz linux-04efcee6ef8d0f01eef495db047e7216d6e6e38f.tar.bz2 linux-04efcee6ef8d0f01eef495db047e7216d6e6e38f.zip | |
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/dev_api.c')
| -rw-r--r-- | net/core/dev_api.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/net/core/dev_api.c b/net/core/dev_api.c index 90bafb0b1b8c..90898cd540ce 100644 --- a/net/core/dev_api.c +++ b/net/core/dev_api.c @@ -327,3 +327,19 @@ int dev_xdp_propagate(struct net_device *dev, struct netdev_bpf *bpf) return ret; } EXPORT_SYMBOL_GPL(dev_xdp_propagate); + +/** + * netdev_state_change() - device changes state + * @dev: device to cause notification + * + * Called to indicate a device has changed state. This function calls + * the notifier chains for netdev_chain and sends a NEWLINK message + * to the routing socket. + */ +void netdev_state_change(struct net_device *dev) +{ + netdev_lock_ops(dev); + netif_state_change(dev); + netdev_unlock_ops(dev); +} +EXPORT_SYMBOL(netdev_state_change); |