SB20260815224 - Use-after-free in Linux kernel ipv4

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-74257)

CWE-ID: CWE-416 - Use After Free

CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

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

The vulnerability exists due to a use-after-free in udp_bpf_recvmsg() when processing concurrent recvmsg operations on BPF-enabled UDP sockets. A local user can trigger concurrent socket receive operations to cause a denial of service.

The issue arises because sk_msg_recvmsg() accesses an ingress message under a lock but processes it without serialization, allowing multiple threads to touch the same sk_msg.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/39d44ed6904bfa9a1c6d0538672dd50c7b85520e
• https://git.kernel.org/stable/c/81567d2b3f4dc4fc32f8b61433738bce2cafd4a1
• https://git.kernel.org/stable/c/c010995b29c8939c6aa69e3cb26f8dbee163d156