Use-after-free in Linux kernel - CVE-2021-47338

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Main Vulnerability Database Vulnerabilities #VU90130

Use-after-free in Linux kernel - CVE-2021-47338

Published: May 31, 2024 / Updated: May 14, 2025


Vulnerability identifier: #VU90130
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-2021-47338
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

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

The vulnerability exists due to a use-after-free error within the fb_set_var() function in drivers/video/fbdev/core/fbmem.c. A local user can escalate privileges on the system.


Affected software

Linux kernel
Oracle Linux
SUSE Linux Enterprise High Availability Extension 15
SUSE Linux Enterprise High Performance Computing 15
SUSE Linux Enterprise Server 15
SUSE Linux Enterprise Server for SAP Applications 15
SUSE Linux Enterprise High Performance Computing LTSS 15
SUSE Manager Proxy
SUSE Manager Retail Branch Server
SUSE Manager Server
SUSE Linux Enterprise Micro
SUSE Linux Enterprise Micro for Rancher
SUSE Enterprise Storage
Anolis OS
Red Hat CodeReady Linux Builder for ARM 64
Red Hat CodeReady Linux Builder for Power, little endian
Red Hat CodeReady Linux Builder for x86_64
Red Hat Enterprise Linux for ARM 64
Red Hat Enterprise Linux for Power, little endian
Red Hat Enterprise Linux for IBM z Systems
Red Hat Enterprise Linux for x86_64
Red Hat Enterprise Linux for Real Time for NFV
Red Hat Enterprise Linux for Real Time
SUSE Linux Enterprise High Performance Computing 15 SP2 LTSS
SUSE Linux Enterprise Live Patching
SUSE Linux Enterprise Server 15 SP2 Business Critical Linux
SUSE Linux Enterprise Server 15 SP2 LTSS
SUSE Linux Enterprise Server 15 SP3 LTSS
SUSE Linux Enterprise Server 15 SP3 Business Critical Linux
openSUSE Leap
kernel-livepatch-5_3_18-150200_24_194-default-debuginfo
kernel-livepatch-5_3_18-150200_24_194-default
kernel-livepatch-SLE15-SP2_Update_49-debugsource
kernel-livepatch-5_3_18-150300_59_164-preempt
kernel-livepatch-SLE15-SP3_Update_45-debugsource
kernel-livepatch-5_3_18-150300_59_164-default-debuginfo
kernel-livepatch-5_3_18-150300_59_164-default
kernel-livepatch-5_3_18-150300_59_164-preempt-debuginfo
kernel (Red Hat package)
kernel-rt (Red Hat package)
perf
kernel-doc
kernel-tools-libs-devel
kernel-tools-libs
kernel-tools
kernel-modules-extra
kernel-modules
kernel-headers
kernel-devel
kernel-debug-modules-extra
kernel-debug-modules
kernel-debug-devel
kernel-debug-core
kernel-debug
kernel-cross-headers
kernel-core
kernel
bpftool
kernel-abi-stablelists
python3-perf
kernel-default
kernel-default-livepatch
kernel-default-livepatch-devel
kernel-default-debuginfo
kernel-default-debugsource
gfs2-kmp-default-debuginfo
cluster-md-kmp-default-debuginfo
dlm-kmp-default-debuginfo
gfs2-kmp-default
cluster-md-kmp-default
ocfs2-kmp-default-debuginfo
dlm-kmp-default
ocfs2-kmp-default
kernel-preempt
kernel-preempt-debuginfo
kernel-preempt-devel
kernel-preempt-devel-debuginfo
kernel-obs-build
kernel-default-devel-debuginfo
kernel-default-devel
kernel-preempt-debugsource
kernel-syms
kernel-obs-build-debugsource
kernel-source
kernel-macros
kernel-docs
reiserfs-kmp-default-debuginfo
reiserfs-kmp-default
kernel-default-base
kernel-64kb-devel-debuginfo
kernel-zfcpdump-debuginfo
dtb-aarch64
dtb-rockchip
dtb-sprd
gfs2-kmp-preempt
dtb-altera
dtb-mediatek
dtb-marvell
dtb-qcom
dlm-kmp-64kb-debuginfo
dtb-amd
dtb-hisilicon
kernel-64kb-optional-debuginfo
dtb-socionext
dtb-exynos
dtb-apm
ocfs2-kmp-64kb-debuginfo
kernel-64kb-optional
dtb-freescale
reiserfs-kmp-64kb
kernel-64kb-livepatch-devel
kernel-64kb-debugsource
dtb-arm
reiserfs-kmp-64kb-debuginfo
kernel-64kb
dtb-allwinner
dtb-lg
dtb-al
kernel-64kb-extra-debuginfo
dtb-amlogic
dtb-nvidia
cluster-md-kmp-64kb-debuginfo
gfs2-kmp-64kb-debuginfo
kernel-64kb-extra
cluster-md-kmp-64kb
dtb-broadcom
dtb-xilinx
dtb-renesas
kselftests-kmp-64kb-debuginfo
dtb-cavium
kernel-64kb-devel
gfs2-kmp-64kb
dlm-kmp-64kb
kselftests-kmp-64kb
ocfs2-kmp-64kb
kernel-64kb-debuginfo
dtb-zte
kernel-kvmsmall-debuginfo
kernel-kvmsmall-livepatch-devel
kernel-default-extra
kernel-default-optional
kernel-kvmsmall-devel
kernel-source-vanilla
kernel-docs-html
kernel-kvmsmall
kernel-zfcpdump
kernel-debug-livepatch-devel
kernel-kvmsmall-debugsource
kernel-debug-debugsource
kernel-debug-debuginfo
kernel-debug-devel-debuginfo
kernel-kvmsmall-devel-debuginfo
kernel-preempt-optional-debuginfo
kselftests-kmp-preempt
cluster-md-kmp-preempt-debuginfo
reiserfs-kmp-preempt-debuginfo
kernel-preempt-optional
kernel-preempt-extra
dlm-kmp-preempt
kselftests-kmp-default
kernel-preempt-livepatch-devel
reiserfs-kmp-preempt
ocfs2-kmp-preempt-debuginfo
dlm-kmp-preempt-debuginfo
kernel-preempt-extra-debuginfo
kernel-zfcpdump-debugsource
kernel-obs-qa
kernel-default-optional-debuginfo
kselftests-kmp-default-debuginfo
kernel-default-extra-debuginfo
cluster-md-kmp-preempt
gfs2-kmp-preempt-debuginfo
ocfs2-kmp-preempt
kselftests-kmp-preempt-debuginfo
kernel-default-base-rebuild
kernel-rt-debugsource
kernel-source-rt
kernel-rt-debuginfo
kernel-rt
Technical Support Appliance
EMC Cloud Tiering Appliance
Red Hat OpenShift Container Platform
OpenShift Logging

How to mitigate CVE-2021-47338

Install update from vendor's website.

Linux kernel - addressed in versions 5.4.134, 5.10.52, 5.12.19, 5.13.4, 5.14
kernel-livepatch-5_3_18-150200_24_194-default-debuginfo - update to 1-150200.5.3.1
kernel-livepatch-5_3_18-150200_24_194-default - update to 1-150200.5.3.1
kernel-livepatch-SLE15-SP2_Update_49-debugsource - update to 1-150200.5.3.1
kernel-livepatch-5_3_18-150300_59_164-preempt - update to 1-150300.7.3.1
kernel-livepatch-SLE15-SP3_Update_45-debugsource - update to 1-150300.7.3.1
kernel-livepatch-5_3_18-150300_59_164-default-debuginfo - update to 1-150300.7.3.1
kernel-livepatch-5_3_18-150300_59_164-default - update to 1-150300.7.3.1
kernel-livepatch-5_3_18-150300_59_164-preempt-debuginfo - update to 1-150300.7.3.1
Technical Support Appliance - update to 3.0.1
Red Hat OpenShift Container Platform - addressed in versions 4.13.52, 4.14.38, 4.15.35
kernel (Red Hat package) - update to 4.18.0-553.22.1.el8_10
kernel-rt (Red Hat package) - update to 4.18.0-553.22.1.rt7.363.el8_10
perf - update to 4.18.0-553.22.1.0.1
kernel-doc - update to 4.18.0-553.22.1.0.1
kernel-tools-libs-devel - update to 4.18.0-553.22.1.0.1
kernel-tools-libs - update to 4.18.0-553.22.1.0.1
kernel-tools - update to 4.18.0-553.22.1.0.1
kernel-modules-extra - update to 4.18.0-553.22.1.0.1
kernel-modules - update to 4.18.0-553.22.1.0.1
kernel-headers - update to 4.18.0-553.22.1.0.1
kernel-devel - update to 4.18.0-553.22.1.0.1
kernel-debug-modules-extra - update to 4.18.0-553.22.1.0.1
kernel-debug-modules - update to 4.18.0-553.22.1.0.1
kernel-debug-devel - update to 4.18.0-553.22.1.0.1
kernel-debug-core - update to 4.18.0-553.22.1.0.1
kernel-debug - update to 4.18.0-553.22.1.0.1
kernel-cross-headers - update to 4.18.0-553.22.1.0.1
kernel-core - update to 4.18.0-553.22.1.0.1
kernel - update to 4.18.0-553.22.1.0.1
bpftool - update to 4.18.0-553.22.1.0.1
kernel-abi-stablelists - update to 4.18.0-553.22.1.0.1
python3-perf - update to 4.18.0-553.22.1.0.1
kernel-devel - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-livepatch - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-livepatch-devel - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-debugsource - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
gfs2-kmp-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
cluster-md-kmp-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
dlm-kmp-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
gfs2-kmp-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
cluster-md-kmp-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
ocfs2-kmp-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
dlm-kmp-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
ocfs2-kmp-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-preempt - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-preempt-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-preempt-devel - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-preempt-devel-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-obs-build - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-devel-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-devel - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-preempt-debugsource - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-syms - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-obs-build-debugsource - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-source - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-macros - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-docs - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
reiserfs-kmp-default-debuginfo - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
reiserfs-kmp-default - addressed in versions 5.3.18-150200.24.194.1, 5.3.18-150300.59.164.1
kernel-default-base - addressed in versions 5.3.18-150200.24.194.1.150200.9.99.1, 5.3.18-150300.59.164.1.150300.18.96.1
kernel-64kb-devel-debuginfo - update to 5.3.18-150300.59.164.1
kernel-zfcpdump-debuginfo - update to 5.3.18-150300.59.164.1
dtb-aarch64 - update to 5.3.18-150300.59.164.1
dtb-rockchip - update to 5.3.18-150300.59.164.1
dtb-sprd - update to 5.3.18-150300.59.164.1
gfs2-kmp-preempt - update to 5.3.18-150300.59.164.1
dtb-altera - update to 5.3.18-150300.59.164.1
dtb-mediatek - update to 5.3.18-150300.59.164.1
dtb-marvell - update to 5.3.18-150300.59.164.1
dtb-qcom - update to 5.3.18-150300.59.164.1
dlm-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
dtb-amd - update to 5.3.18-150300.59.164.1
dtb-hisilicon - update to 5.3.18-150300.59.164.1
kernel-64kb-optional-debuginfo - update to 5.3.18-150300.59.164.1
dtb-socionext - update to 5.3.18-150300.59.164.1
dtb-exynos - update to 5.3.18-150300.59.164.1
dtb-apm - update to 5.3.18-150300.59.164.1
ocfs2-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
kernel-64kb-optional - update to 5.3.18-150300.59.164.1
dtb-freescale - update to 5.3.18-150300.59.164.1
reiserfs-kmp-64kb - update to 5.3.18-150300.59.164.1
kernel-64kb-livepatch-devel - update to 5.3.18-150300.59.164.1
kernel-64kb-debugsource - update to 5.3.18-150300.59.164.1
dtb-arm - update to 5.3.18-150300.59.164.1
reiserfs-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
kernel-64kb - update to 5.3.18-150300.59.164.1
dtb-allwinner - update to 5.3.18-150300.59.164.1
dtb-lg - update to 5.3.18-150300.59.164.1
dtb-al - update to 5.3.18-150300.59.164.1
kernel-64kb-extra-debuginfo - update to 5.3.18-150300.59.164.1
dtb-amlogic - update to 5.3.18-150300.59.164.1
dtb-nvidia - update to 5.3.18-150300.59.164.1
cluster-md-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
gfs2-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
kernel-64kb-extra - update to 5.3.18-150300.59.164.1
cluster-md-kmp-64kb - update to 5.3.18-150300.59.164.1
dtb-broadcom - update to 5.3.18-150300.59.164.1
dtb-xilinx - update to 5.3.18-150300.59.164.1
dtb-renesas - update to 5.3.18-150300.59.164.1
kselftests-kmp-64kb-debuginfo - update to 5.3.18-150300.59.164.1
dtb-cavium - update to 5.3.18-150300.59.164.1
kernel-64kb-devel - update to 5.3.18-150300.59.164.1
gfs2-kmp-64kb - update to 5.3.18-150300.59.164.1
dlm-kmp-64kb - update to 5.3.18-150300.59.164.1
kselftests-kmp-64kb - update to 5.3.18-150300.59.164.1
ocfs2-kmp-64kb - update to 5.3.18-150300.59.164.1
kernel-64kb-debuginfo - update to 5.3.18-150300.59.164.1
dtb-zte - update to 5.3.18-150300.59.164.1
kernel-kvmsmall-debuginfo - update to 5.3.18-150300.59.164.1
kernel-kvmsmall-livepatch-devel - update to 5.3.18-150300.59.164.1
kernel-default-extra - update to 5.3.18-150300.59.164.1
kernel-default-optional - update to 5.3.18-150300.59.164.1
kernel-kvmsmall-devel - update to 5.3.18-150300.59.164.1
kernel-source-vanilla - update to 5.3.18-150300.59.164.1
kernel-docs-html - update to 5.3.18-150300.59.164.1
kernel-kvmsmall - update to 5.3.18-150300.59.164.1
kernel-debug - update to 5.3.18-150300.59.164.1
kernel-zfcpdump - update to 5.3.18-150300.59.164.1
kernel-debug-devel - update to 5.3.18-150300.59.164.1
kernel-debug-livepatch-devel - update to 5.3.18-150300.59.164.1
kernel-kvmsmall-debugsource - update to 5.3.18-150300.59.164.1
kernel-debug-debugsource - update to 5.3.18-150300.59.164.1
kernel-debug-debuginfo - update to 5.3.18-150300.59.164.1
kernel-debug-devel-debuginfo - update to 5.3.18-150300.59.164.1
kernel-kvmsmall-devel-debuginfo - update to 5.3.18-150300.59.164.1
kernel-preempt-optional-debuginfo - update to 5.3.18-150300.59.164.1
kselftests-kmp-preempt - update to 5.3.18-150300.59.164.1
cluster-md-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
reiserfs-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
kernel-preempt-optional - update to 5.3.18-150300.59.164.1
kernel-preempt-extra - update to 5.3.18-150300.59.164.1
dlm-kmp-preempt - update to 5.3.18-150300.59.164.1
kselftests-kmp-default - update to 5.3.18-150300.59.164.1
kernel-preempt-livepatch-devel - update to 5.3.18-150300.59.164.1
reiserfs-kmp-preempt - update to 5.3.18-150300.59.164.1
ocfs2-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
dlm-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
kernel-preempt-extra-debuginfo - update to 5.3.18-150300.59.164.1
kernel-zfcpdump-debugsource - update to 5.3.18-150300.59.164.1
kernel-obs-qa - update to 5.3.18-150300.59.164.1
kernel-default-optional-debuginfo - update to 5.3.18-150300.59.164.1
kselftests-kmp-default-debuginfo - update to 5.3.18-150300.59.164.1
kernel-default-extra-debuginfo - update to 5.3.18-150300.59.164.1
cluster-md-kmp-preempt - update to 5.3.18-150300.59.164.1
gfs2-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
ocfs2-kmp-preempt - update to 5.3.18-150300.59.164.1
kselftests-kmp-preempt-debuginfo - update to 5.3.18-150300.59.164.1
kernel-default-base-rebuild - update to 5.3.18-150300.59.164.1.150300.18.96.1
kernel-rt-debugsource - update to 5.3.18-150300.172.1
kernel-source-rt - update to 5.3.18-150300.172.1
kernel-rt-debuginfo - update to 5.3.18-150300.172.1
kernel-rt - update to 5.3.18-150300.172.1
OpenShift Logging - update to 5.6.25
EMC Cloud Tiering Appliance - update to 13.2.0.2.31

External References

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