CVE-2024-53088: i40e: fix race condition by adding filter's intermediate sync state

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

i40e: fix race condition by adding filter's intermediate sync state

Fix a race condition in the i40e driver that leads to MAC/VLAN filters becoming corrupted and leaking. Address the issue that occurs under heavy load when multiple threads are concurrently modifying MAC/VLAN filters by setting mac and port VLAN.

1. Thread T0 allocates a filter in i40eaddfilter() within i40endosetvfportvlan(). 2. Thread T1 concurrently frees the filter in i40edelfilter() within i40endosetvfmac(). 3. Subsequently, i40eservicetask() calls i40esyncvsifilters(), which refers to the already freed filter memory, causing corruption.

Reproduction steps: 1. Spawn multiple VFs. 2. Apply a concurrent heavy load by running parallel operations to change MAC addresses on the VFs and change port VLANs on the host. 3. Observe errors in dmesg: "Error I40EAQRCENOSPC adding RX filters on VF XX, please set promiscuous on manually for VF XX".

Exact code for stable reproduction Intel can't open-source now.

The fix involves implementing a new intermediate filter state, I40EFILTERNEWSYNC, for the time when a filter is on a tmpaddlist. These filters cannot be deleted from the hash list directly but must be removed using the full process.