SB20260816316 - Race condition in Linux kernel sunrpc

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-72221)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: 8.2 [CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

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

The vulnerability exists due to a race condition in svc_tcp_handshake() in the sunrpc server socket handling code when processing a TLS handshake callback during handshake cancellation. A remote attacker can trigger a TLS handshake timeout or interruption and cause concurrent handshake completion to corrupt the embedded swait_queue or tear down the connection to cause a denial of service.

The issue occurs when cancellation loses the race to handshake completion and the callback is still in flight.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/0d8ceb39884148dc7a2fdf71e1cac5961ed1d2b9
• https://git.kernel.org/stable/c/65b23bec1fca6e9ebdc3e6041ebf8c6ab074141b
• https://git.kernel.org/stable/c/a4f878e8ecd729ccf2e50993444e217583adeace
• https://git.kernel.org/stable/c/d00e32f84ca1a77cb67a3fbf59f58dada95f5a21
• https://git.kernel.org/stable/c/e0f4691d42a54d359d8b64509fd9ab938d4f2a33