CVE-2026-98359

In the Linux kernel, the following vulnerability has been resolved:

RDMA/core: Reject unregistering netdevs in ib get eth speed

ib device get netdev() intentionally returns a referenced net device even when it is unregistering, so matching and cleanup callers can still find the association. The reference keeps struct net device allocated, but does not guarantee that the device remains operational.

ib get eth speed() uses the returned device operationally by invoking its ethtool callback. Although that call is made under RTNL, the function does not verify the registration state first. An asynchronous RDMA port query can therefore call into a netdev after NETDEV UNREGISTER and ndo uninit have completed.

Check for NETREG REGISTERED while holding RTNL and return -ENODEV for a device which is being unregistered. Keeping RTNL across the check and the ethtool operation prevents unregister from starting between them.

Keep the speed fallback and warning under RTNL as well, so the warning can safely read netdev->name. Drop the netdev reference before releasing RTNL once all accesses to the device are complete.