Bug 2320632 (CVE-2024-50041)

Summary: CVE-2024-50041 kernel: i40e: Fix macvlan leak by synchronizing access to mac_filter_hash
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: If docs needed, set a value
Doc Text:
Story Points: ---
Clone Of: Environment:
Last Closed: Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 2320883    
Bug Blocks:    

Description OSIDB Bzimport 2024-10-21 20:04:49 UTC
In the Linux kernel, the following vulnerability has been resolved:

i40e: Fix macvlan leak by synchronizing access to mac_filter_hash

This patch addresses a macvlan leak issue in the i40e driver caused by
concurrent access to vsi->mac_filter_hash. The leak occurs when multiple
threads attempt to modify the mac_filter_hash simultaneously, leading to
inconsistent state and potential memory leaks.

To fix this, we now wrap the calls to i40e_del_mac_filter() and zeroing
vf->default_lan_addr.addr with spin_lock/unlock_bh(&vsi->mac_filter_hash_lock),
ensuring atomic operations and preventing concurrent access.

Additionally, we add lockdep_assert_held(&vsi->mac_filter_hash_lock) in
i40e_add_mac_filter() to help catch similar issues in the future.

Reproduction steps:
1. Spawn VFs and configure port vlan on them.
2. Trigger concurrent macvlan operations (e.g., adding and deleting
	portvlan and/or mac filters).
3. Observe the potential memory leak and inconsistent state in the
	mac_filter_hash.

This synchronization ensures the integrity of the mac_filter_hash and prevents
the described leak.

Comment 1 Avinash Hanwate 2024-10-22 09:31:57 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2024102133-CVE-2024-50041-6118@gregkh/T