Use-after-free in Linux kernel - CVE-2026-63816

Vulnerability identifier: #VU138840

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-2026-63816

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 f2fs garbage collection code when handling F2FS_IOC_GARBAGE_COLLECT_RANGE on a copy-on-write file. A local user can trigger garbage collection while the associated atomic inode is being evicted to cause a denial of service.

The issue involves access to atomic_inode->i_mapping without holding a reference to the atomic inode.

Linux kernel
Debian Linux
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux (Debian package)
linux (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1036.39+1
linux (Debian package) - update to 6.12.96-1
linux (Ubuntu package) - addressed in versions 7.0.0-31.31~24.04.1, 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12~24.04.1, 7.0.0-1012.12
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

• https://git.kernel.org/stable/c/56038756aae68312df00d4aa1d97e51ef3aca725
• https://git.kernel.org/stable/c/a499f77c06050a28c897bdbd86cd2f0721ae0743
• https://git.kernel.org/stable/c/a805fec35c201c59643ddcde713bce4051c8ee27
• https://git.kernel.org/stable/c/e0288584baa5dc41df4a829a023c4c1b33fe53d7

• Use-after-free in Linux kernel f2fs
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-ibm
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia-7.0
• Ubuntu update for linux-nvidia-tegra