SB20260816177 - Memory leak in Linux kernel ipv4

Description

This security bulletin contains information about 1 vulnerability.

1) Memory leak (CVE-ID: CVE-2026-74543)

CWE-ID: CWE-401 - Missing release of memory after effective lifetime

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local attacker to cause a denial of service.

The vulnerability exists due to a memory leak in udp_tunnel_nic_unregister() when handling failed device registration and netdevice unregister events. A local attacker can trigger device registration failure with queued work to cause a denial of service.

The issue occurs because a queued work item can cause the unregister path to return early, leaving a struct udp_tunnel_nic allocation permanently leaked.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/080695e6f005e2396f1207fd69d24c442cb230c6
• https://git.kernel.org/stable/c/b322532a4b774db1b480a2de84125910a70739a5
• https://git.kernel.org/stable/c/b712da45bd9b9835d132e9fbc0c3e43c164cb1fd
• https://git.kernel.org/stable/c/f82a2ded3d7a9098267c84f14eafdb98c4550ac5