Use-after-free in Linux kernel - CVE-2026-63884

Vulnerability identifier: #VU138767

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-2026-63884

CWE-ID: CWE-416

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 use-after-free in the i915 TTM object purge logic when purging an object during eviction after validating buffer object placement. A local user can trigger the purge path through crafted GPU memory management operations to cause a denial of service.

The issue was reported under heavy use on DG2 systems and occurs because the associated i915 TTM page vector container may be replaced while the object is still busy.

Linux kernel
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for ARM 64
Red Hat CodeReady Linux Builder for x86_64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for ARM 64
Red Hat Enterprise Linux for Real Time
Red Hat Enterprise Linux for Real Time for NFV
Ubuntu
kernel (Red Hat package)
kernel-rt-debug (Red Hat package)
kernel-rt-debug-devel (Red Hat package)
kernel-rt-debug-modules-extra (Red Hat package)
kernel-rt-kvm (Red Hat package)
linux-ibm (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (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
kernel (Red Hat package) - update to 4.18.0-553.156.1.el8_10
kernel-rt-debug (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-devel (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-debug-modules-extra (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
kernel-rt-kvm (Red Hat package) - update to 4.18.0-553.156.1.rt7.497.el8_10
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15
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/073bcbc95e9648c976da1654c7590a8d6ee12c2d
• https://git.kernel.org/stable/c/28b22dbaf407598cb3bb1d2c586a6f8018690ac2
• https://git.kernel.org/stable/c/5c4063c87a619e4df954c179d24628636f5db15f
• https://git.kernel.org/stable/c/a29654d451bbffe63d584a4cf64ad0efce6bcf1c
• https://git.kernel.org/stable/c/c9ae7e7e3bc98615364313b08d7acea5239ded0b
• https://git.kernel.org/stable/c/df73f3bc731af1c39ac5405bc59c4e7c6f8e9117

• Use-after-free in Linux kernel i915 gem driver
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws
• Red Hat Enterprise Linux 8 update for kernel
• Red Hat Enterprise Linux 8 update for kernel-rt
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-nvidia