Race condition in Linux kernel - CVE-2026-63879

Vulnerability identifier: #VU138779

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-2026-63879

CWE-ID: CWE-362

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 improper synchronization in amdgpu_hmm_range_get_pages in the AMDGPU HMM handling code when reading the notifier sequence across range processing. A local user can trigger memory invalidation during page range handling to cause a denial of service.

The issue can result in operations being performed on invalid pages.

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/2fd24407457a6b181ba827705678da70e528dcd0
• https://git.kernel.org/stable/c/962d684b5dc0741dcd93485d41b450de402d5592

• Race condition in Linux kernel amd amdgpu 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