NULL pointer dereference in Linux kernel - CVE-2026-64234

Vulnerability identifier: #VU139770

CSH Severity: Low

CVSS v4: 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]

CVE-ID: CVE-2026-64234

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

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

The vulnerability exists due to a NULL pointer dereference in dma_handle_rx() in the pch_uart driver when handling DMA receive operations after coherent DMA buffer allocation fails. A local user can trigger allocation failure conditions to cause a denial of service.

Linux kernel
Ubuntu
linux-aws (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-nvidia (Ubuntu package) - addressed in versions 7.0.0-1016.16, 7.0.0-1016.16~24.04.1
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2016.16

• https://git.kernel.org/stable/c/5f2e2a240dc1846e049bc67e9c3cdf5b031d08bf
• https://git.kernel.org/stable/c/66f8bfea055b23719b4fd6ce207c44de37d82a59
• https://git.kernel.org/stable/c/6dd5c0ea139b586ad5a091677056dafd405cfe82
• https://git.kernel.org/stable/c/6fe472c1bbbe238e91141f7cabc1226e96a60d43
• https://git.kernel.org/stable/c/760df81763b391bb5f0dcb0b7597b736da753ae4
• https://git.kernel.org/stable/c/d846df2dfbc2469a688833b4cc4f8aa80672bde8
• https://git.kernel.org/stable/c/d8d53a343ebe74274ca17b1e1993042e99f8c863
• https://git.kernel.org/stable/c/daea997bb244aeb50cbb2e5e075fb446a6cf068f

• NULL pointer dereference in Linux kernel tty serial driver
• Ubuntu update for linux-aws
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-gcp-7.0