Use-after-free in Linux kernel - CVE-2021-47123

Vulnerability identifier: #VU90226

CSH Severity: Low

CVSS v4 BT: 5.9 [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/E:U/U:Clear]

CVE-ID: CVE-2021-47123

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

Linux kernel
openEuler
kernel
python2-perf-debuginfo
kernel-debugsource
python3-perf
kernel-source
kernel-tools-debuginfo
bpftool-debuginfo
python2-perf
kernel-debuginfo
kernel-tools-devel
kernel-tools
perf-debuginfo
python3-perf-debuginfo
kernel-devel
bpftool
perf

Install update from vendor's website.

Linux kernel - addressed in versions 5.12.10, 5.13
kernel - update to 4.19.90-2405.1.0.0248
python2-perf-debuginfo - update to 4.19.90-2405.1.0.0248
kernel-debugsource - update to 4.19.90-2405.1.0.0248
python3-perf - update to 4.19.90-2405.1.0.0248
kernel-source - update to 4.19.90-2405.1.0.0248
kernel-tools-debuginfo - update to 4.19.90-2405.1.0.0248
bpftool-debuginfo - update to 4.19.90-2405.1.0.0248
python2-perf - update to 4.19.90-2405.1.0.0248
kernel-debuginfo - update to 4.19.90-2405.1.0.0248
kernel-tools-devel - update to 4.19.90-2405.1.0.0248
kernel-tools - update to 4.19.90-2405.1.0.0248
perf-debuginfo - update to 4.19.90-2405.1.0.0248
python3-perf-debuginfo - update to 4.19.90-2405.1.0.0248
kernel-devel - update to 4.19.90-2405.1.0.0248
bpftool - update to 4.19.90-2405.1.0.0248
perf - update to 4.19.90-2405.1.0.0248

• https://git.kernel.org/stable/c/1f64f5e903b9d1d157875721e02adadc9d6f0a5d
• https://git.kernel.org/stable/c/447c19f3b5074409c794b350b10306e1da1ef4ba
• https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.12.10
• https://mirrors.edge.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.13

• Use-after-free in Linux kernel fs
• openEuler 20.03 LTS SP1 update for kernel