NULL pointer dereference in Linux kernel - CVE-2026-98508

Vulnerability identifier: #VU156809

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-2026-98508

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 by triggering a kernel fault.

The vulnerability exists due to a null pointer dereference in the Linux kernel virtio GPU driver's submission handling when fence allocation fails under memory pressure. A local user can submit GPU work through the driver's ioctl interface to trigger a path where virtio_gpu_init_submit() passes an unchecked NULL allocation result to virtio_gpu_fence_event_create(), causing a kernel fault and a denial of service.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/846b3c64fe3e77d9db20a7e3e62dbbb637c773e1
• https://git.kernel.org/stable/c/9571ab7493561afb4624d69572a7ebb67d76d10f
• https://git.kernel.org/stable/c/a8b83ed4a4b1d04c756f53e375e86d3881f66e72
• https://git.kernel.org/stable/c/ecced0076b700b5896e52af10d0776be8be36b0d
• https://git.kernel.org/stable/c/f2f1683955b95c9b958069da3050f7e8e129ff88

• NULL pointer dereference in Linux kernel drm virtio driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more