Bug 2516515 (CVE-2026-72344)

Summary: CVE-2026-72344 kernel: net/mlx5e: TC, skip peer flow cleanup when LAG seq is unavailable
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: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
Target Release: ---   
Hardware: All   
OS: Linux   
Whiteboard:
Fixed In Version: Doc Type: ---
Doc Text:
A flaw was found in the Linux kernel's net/mlx5e driver. When the mlx5_lag_get_dev_seq() function encounters an error, such as a peer not being in the Link Aggregation Group (LAG) or no master device being marked, the system attempts to clean up peer flows without proper validation. This improper handling can lead to bad memory access and a kernel crash, resulting in a denial of service.
 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:

Description OSIDB Bzimport 2026-08-15 06:16:32 UTC 
In the Linux kernel, the following vulnerability has been resolved:

net/mlx5e: TC, skip peer flow cleanup when LAG seq is unavailable

mlx5_lag_get_dev_seq() will return error when the peer isn't in the LAG
or when no device is marked as master. Result bad memory access and kernel
crash[1].

Hence, skip the peer when lookup fails.

Note: In case there are peer flows, they are cleaned before LAG cleared
the master mark.

[1]
RIP: 0010:mlx5e_tc_del_fdb_peers_flow+0x3d/0x350 [mlx5_core]
Call Trace:
 <TASK>
 mlx5e_tc_clean_fdb_peer_flows+0xc1/0x130 [mlx5_core]
 mlx5_esw_offloads_unpair+0x3a/0x400 [mlx5_core]
 mlx5_esw_offloads_devcom_event+0xee/0x360 [mlx5_core]
 mlx5_devcom_send_event+0x7a/0x140 [mlx5_core]
 mlx5_esw_offloads_devcom_cleanup+0x2f/0x90 [mlx5_core]
 mlx5e_tc_esw_cleanup+0x28/0xf0 [mlx5_core]
 mlx5e_rep_tc_cleanup+0x19/0x30 [mlx5_core]
 mlx5e_cleanup_uplink_rep_tx+0x36/0x40 [mlx5_core]
 mlx5e_cleanup_rep_tx+0x55/0x60 [mlx5_core]
 mlx5e_detach_netdev+0x96/0xf0 [mlx5_core]
 mlx5e_netdev_change_profile+0x5b/0x120 [mlx5_core]
 mlx5e_netdev_attach_nic_profile+0x1b/0x30 [mlx5_core]
 mlx5e_vport_rep_unload+0xdd/0x110 [mlx5_core]
 __esw_offloads_unload_rep+0x81/0xb0 [mlx5_core]
 mlx5_eswitch_unregister_vport_reps+0x1d7/0x220 [mlx5_core]
 mlx5e_rep_remove+0x22/0x30 [mlx5_core]
 device_release_driver_internal+0x194/0x1f0
 bus_remove_device+0xe8/0x1b0
 device_del+0x159/0x3c0
 mlx5_rescan_drivers_locked+0xbc/0x2d0 [mlx5_core]
 mlx5_unregister_device+0x54/0x80 [mlx5_core]
 mlx5_uninit_one+0x73/0x130 [mlx5_core]
 remove_one+0x78/0xe0 [mlx5_core]
 pci_device_remove+0x39/0xa0
Comment 1 Keith Grant 2026-08-19 13:33:43 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026081510-CVE-2026-72344-6b98@gregkh/T