Improper update of reference count in Linux kernel - CVE-2026-98511

Vulnerability identifier: #VU156812

CSH Severity: Low

CVSS v4: 0 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98511

CWE-ID: CWE-911

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to trigger a kernel warning during buffer-object release.

The vulnerability exists due to incorrect pin-count accounting in the nouveau driver's buffer-object pinning logic when processing a re-pin request for an already pinned buffer object in an incompatible memory domain. A local user can trigger a failed re-pin request that nevertheless increments the pin count, leaving an unmatched pin that triggers a warning in ttm_bo_release() when the buffer object is released.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (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-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
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/189ffc7b6cad6390c0695031cb6c7c63472981e8
• https://git.kernel.org/stable/c/19f5a5839b308697824ff46e6213a2b4cb677771
• https://git.kernel.org/stable/c/5cb7109f0f5f1b47b172e2d5b868d4ce3ae687f8
• https://git.kernel.org/stable/c/6a6870d3077faa501ca97760057ddca22b68418d
• https://git.kernel.org/stable/c/73c7093e6cc1e6b181a79e16eccc4b8d4f34d8ee
• https://git.kernel.org/stable/c/9924c1d64405be8d10b906368dfb1cfe0d0c6bf0
• https://git.kernel.org/stable/c/a6e755acf85793a7b4d29ba27b5421af1087263f

• Improper update of reference count in Linux kernel drm nouveau driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more