Use-after-free in Linux kernel - CVE-2025-21633

Vulnerability identifier: #VU103012

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-2025-21633

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 io_sq_thread() function in io_uring/sqpoll.c. A local user can escalate privileges on the system.

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
Ubuntu
Red Hat OpenShift Dev Spaces
kernel (Red Hat package)
linux-image-6.11.0-21-generic (Ubuntu package)
linux-image-oem-24.04a (Ubuntu package)
linux-image-oem-24.04 (Ubuntu package)
linux-image-generic-hwe-24.04 (Ubuntu package)
linux-image-generic-64k-hwe-24.04 (Ubuntu package)
linux-image-generic-64k (Ubuntu package)
linux-image-generic (Ubuntu package)
linux-image-virtual (Ubuntu package)
linux-image-virtual-hwe-24.04 (Ubuntu package)
linux-image-6.11.0-21-generic-64k (Ubuntu package)
linux-image-realtime (Ubuntu package)
linux-image-realtime-hwe-24.04 (Ubuntu package)
linux-image-6.11.0-1007-realtime (Ubuntu package)
linux-image-raspi (Ubuntu package)
linux-image-6.11.0-1010-raspi (Ubuntu package)
linux-image-6.11.0-1011-gcp-64k (Ubuntu package)
linux-image-gcp-64k (Ubuntu package)
linux-image-gcp (Ubuntu package)
linux-image-6.11.0-1011-gcp (Ubuntu package)
linux-image-lowlatency (Ubuntu package)
linux-image-lowlatency-64k (Ubuntu package)
linux-image-aws (Ubuntu package)
linux-image-6.11.0-1011-aws (Ubuntu package)
linux-image-6.11.0-1011-lowlatency-64k (Ubuntu package)
linux-image-6.11.0-1011-lowlatency (Ubuntu package)
linux-image-lowlatency-hwe-24.04 (Ubuntu package)
linux-image-lowlatency-64k-hwe-24.04 (Ubuntu package)
linux-image-azure (Ubuntu package)
linux-image-azure-fde (Ubuntu package)
linux-image-6.11.0-1012-azure-fde (Ubuntu package)
linux-image-6.11.0-1012-azure (Ubuntu package)
linux-image-oracle-64k (Ubuntu package)
linux-image-oracle (Ubuntu package)
linux-image-6.11.0-1013-oracle-64k (Ubuntu package)
linux-image-6.11.0-1013-oracle (Ubuntu package)
linux-image-6.11.0-1017-oem (Ubuntu package)
linux-image-oem-24.04b (Ubuntu package)

Install update from vendor's website.

Linux kernel - update to 6.12.10
Red Hat OpenShift Dev Spaces - update to 3.21.0
kernel (Red Hat package) - update to 5.14.0-570.16.1.el9_6
linux-image-6.11.0-21-generic (Ubuntu package) - addressed in versions 6.11.0-21.21, 6.11.0-21.21~24.04.1+1
linux-image-oem-24.04a (Ubuntu package) - update to 6.11.0-21.21
linux-image-oem-24.04 (Ubuntu package) - update to 6.11.0-21.21
linux-image-generic-hwe-24.04 (Ubuntu package) - addressed in versions 6.11.0-21.21, 6.11.0-21.21~24.04.1
linux-image-generic-64k-hwe-24.04 (Ubuntu package) - addressed in versions 6.11.0-21.21, 6.11.0-21.21~24.04.1
linux-image-generic-64k (Ubuntu package) - update to 6.11.0-21.21
linux-image-generic (Ubuntu package) - update to 6.11.0-21.21
linux-image-virtual (Ubuntu package) - update to 6.11.0-21.21
linux-image-virtual-hwe-24.04 (Ubuntu package) - addressed in versions 6.11.0-21.21, 6.11.0-21.21~24.04.1
linux-image-6.11.0-21-generic-64k (Ubuntu package) - addressed in versions 6.11.0-21.21, 6.11.0-21.21~24.04.1+1
linux-image-realtime (Ubuntu package) - update to 6.11.0-1007.7
linux-image-realtime-hwe-24.04 (Ubuntu package) - update to 6.11.0-1007.7
linux-image-6.11.0-1007-realtime (Ubuntu package) - update to 6.11.0-1007.7
linux-image-raspi (Ubuntu package) - update to 6.11.0-1010.10
linux-image-6.11.0-1010-raspi (Ubuntu package) - update to 6.11.0-1010.10
linux-image-6.11.0-1011-gcp-64k (Ubuntu package) - update to 6.11.0-1011.11
linux-image-gcp-64k (Ubuntu package) - update to 6.11.0-1011.11
linux-image-gcp (Ubuntu package) - update to 6.11.0-1011.11
linux-image-6.11.0-1011-gcp (Ubuntu package) - update to 6.11.0-1011.11
linux-image-lowlatency (Ubuntu package) - update to 6.11.0-1011.12
linux-image-lowlatency-64k (Ubuntu package) - update to 6.11.0-1011.12
linux-image-aws (Ubuntu package) - update to 6.11.0-1011.12
linux-image-6.11.0-1011-aws (Ubuntu package) - update to 6.11.0-1011.12
linux-image-6.11.0-1011-lowlatency-64k (Ubuntu package) - update to 6.11.0-1011.12~24.04.1
linux-image-6.11.0-1011-lowlatency (Ubuntu package) - update to 6.11.0-1011.12~24.04.1
linux-image-lowlatency-hwe-24.04 (Ubuntu package) - update to 6.11.0-1011.12~24.04.1
linux-image-lowlatency-64k-hwe-24.04 (Ubuntu package) - update to 6.11.0-1011.12~24.04.1
linux-image-azure (Ubuntu package) - update to 6.11.0-1012.12
linux-image-azure-fde (Ubuntu package) - update to 6.11.0-1012.12
linux-image-6.11.0-1012-azure-fde (Ubuntu package) - update to 6.11.0-1012.12
linux-image-6.11.0-1012-azure (Ubuntu package) - update to 6.11.0-1012.12
linux-image-oracle-64k (Ubuntu package) - update to 6.11.0-1013.14
linux-image-oracle (Ubuntu package) - update to 6.11.0-1013.14
linux-image-6.11.0-1013-oracle-64k (Ubuntu package) - update to 6.11.0-1013.14
linux-image-6.11.0-1013-oracle (Ubuntu package) - update to 6.11.0-1013.14
linux-image-6.11.0-1017-oem (Ubuntu package) - update to 6.11.0-1017.17
linux-image-oem-24.04b (Ubuntu package) - update to 6.11.0-1017.17

• https://git.kernel.org/stable/c/4b7cfa8b6c28a9fa22b86894166a1a34f6d630ba
• https://git.kernel.org/stable/c/aa7496d668c30ca7421b3bfdcd948ee861a13d17
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.10

• Use-after-free in Linux kernel io_uring
• Ubuntu update for linux-oem-6.11
• Ubuntu update for linux-lowlatency-hwe-6.11
• Ubuntu update for linux-lowlatency
• Ubuntu update for linux
• Ubuntu update for linux-raspi
• Red Hat Enterprise Linux 9 update for kernel
• Multiple vulnerabilities in Red Hat OpenShift Dev Spaces 3.21