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.
- Thread T0 allocates a filter in i40e_add_filter() within
- Thread T1 concurrently frees the filter in __i40e_del_filter() within
- Subsequently, i40e_service_task() calls i40e_sync_vsi_filters(), which
Reproduction steps:
- Spawn multiple VFs.
- Apply a concurrent heavy load by running parallel operations to change
- Observe errors in dmesg:
Exact code for stable reproduction Intel can't open-source now.
The fix involves implementing a new intermediate filter state, I40E_FILTER_NEW_SYNC, for the time when a filter is on a tmp_add_list. These filters cannot be deleted from the hash list directly but must be removed using the full process.