| Description | 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 i40e_add_filter() within
i40e_ndo_set_vf_port_vlan().
2. Thread T1 concurrently frees the filter in __i40e_del_filter() within
i40e_ndo_set_vf_mac().
3. Subsequently, i40e_service_task() calls i40e_sync_vsi_filters(), 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 I40E_AQ_RC_ENOSPC 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,
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. |