Use-after-free in Linux kernel - CVE-2023-26605

Vulnerability identifier: #VU73727

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2023-26605

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a use-after-free error within the inode_cgwb_move_to_attached() function in fs/fs-writeback.c. A local user can trigger a use-after-free error and execute arbitrary code with elevated privileges.

Linux kernel
Ubuntu
linux-image-intel-iotg (Ubuntu package)
linux-image-5.15.0-1026-intel-iotg (Ubuntu package)
linux-image-kvm (Ubuntu package)
linux-image-5.19.0-1019-kvm (Ubuntu package)
linux-image-6.0.0-1014-oem (Ubuntu package)
linux-image-oem-22.04b (Ubuntu package)

Install updates from vendor's website.

linux-image-intel-iotg (Ubuntu package) - update to 5.15.0.1026.25
linux-image-5.15.0-1026-intel-iotg (Ubuntu package) - update to 5.15.0-1026.31
linux-image-kvm (Ubuntu package) - update to 5.19.0.1019.16
linux-image-5.19.0-1019-kvm (Ubuntu package) - update to 5.19.0-1019.20
linux-image-6.0.0-1014-oem (Ubuntu package) - update to 6.0.0-1014.14
linux-image-oem-22.04b (Ubuntu package) - update to 6.0.0.1014.14

• https://lkml.org/lkml/2023/2/22/3

• Use-after-free in Linux kernel
• Ubuntu update for linux-kvm
• Ubuntu update for linux-intel-iotg
• Ubuntu update for linux-oem-6.0