Overview
About vulnerability
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 i40e_ndo_set_vf_port_vlan().
- Thread T1 concurrently frees the filter in __i40e_del_filter() within i40e_ndo_set_vf_mac().
- Subsequently, i40e_service_task() calls i40e_sync_vsi_filters(), which refers to the already freed filter memory, causing corruption.
Reproduction steps:
- Spawn multiple VFs.
- Apply a concurrent heavy load by running parallel operations to change MAC addresses on the VFs and change port VLANs on the host.
- 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.
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , Oracle Linux 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 4.18.0 (+7 more)
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 i40e_ndo_set_vf_port_vlan().
- Thread T1 concurrently frees the filter in __i40e_del_filter() within i40e_ndo_set_vf_mac().
- Subsequently, i40e_service_task() calls i40e_sync_vsi_filters(), which refers to the already freed filter memory, causing corruption.
Reproduction steps:
- Spawn multiple VFs.
- Apply a concurrent heavy load by running parallel operations to change MAC addresses on the VFs and change port VLANs on the host.
- 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.