Vulnerability · Published May 21, 2024 · Assigned by Linux

CVE-2021-47356mISDN: fix possible use-after-free in HFC_cleanup()

High 7.7

In plain English

A high-severity use-after-free in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 19% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.7High
Exploit odds (30 days)0.3%top 81.1% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

In the Linux kernel, the following vulnerability has been resolved: mISDN: fix possible use-after-free in HFC_cleanup() This module's remove path calls del_timer(). However, that function does not wait until the timer handler finishes. This means that the timer handler may still be running after the driver's remove function has finished, which would result in a use-after-free. Fix by calling del_timer_sync(), which makes sure the timer handler has finished, and unable to re-schedule itself.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:8bpftool4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-abi-stablelists4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-core4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-cross-headers4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-debug4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-debug-core4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-debug-devel4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-debug-modules4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-debug-modules-extra4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-devel4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-doc4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-headers4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-modules4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-modules-extra4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-rt4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-core4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug-core4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug-devel4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug-kvm4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug-modules4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-debug-modules-extra4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-devel4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-kvm4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-modules4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-rt-modules-extra4.18.0-553.8.1.rt7.349.el8_10ALSA-2024:4352
AlmaLinux:8kernel-tools4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-tools-libs4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-tools-libs-devel4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-zfcpdump4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-zfcpdump-core4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-zfcpdump-devel4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-zfcpdump-modules4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8kernel-zfcpdump-modules-extra4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8perf4.18.0-553.8.1.el8_10ALSA-2024:4211
AlmaLinux:8python3-perf4.18.0-553.8.1.el8_10ALSA-2024:4211
Debian:12linux5.14.6-1DEBIAN-CVE-2021-47356
Debian:13linux5.14.6-1DEBIAN-CVE-2021-47356
Debian:14linux5.14.6-1DEBIAN-CVE-2021-47356
Rocky Linux:8kernel0:4.18.0-553.8.1.el8_10RLSA-2024:4211
Rocky Linux:8kernel-rt0:4.18.0-553.8.1.rt7.349.el8_10RLSA-2024:4352
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2021-47356
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2021-47356
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2021-47356

Affected products (as reported)

VendorProductVersions
Linux Linux 87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 49331c07ef0f8fdfa42b30ba6a83a657b29d7fbe87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 54ff3202928952a100c477248e65ac6db01258a787c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 7867ddc5f3de7f289aee63233afc0df4b62834c587c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 5f2818185da0fe82a932f0856633038b66faf12487c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 3ecd228c636ee17c14662729737fa07242a93cb087c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before b7ee9ae1e0cf55a037c4a99af2acc5d78cb7802d87c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before 61370ff07e0acc657559a8fac02551dfeb9d302087c5fa1bb42624254a2013cbbc3b170d6017f5d6 – before ed7c3739d0a07e2ec3ccbffe7e93cea01c438cda
Linux Linux 2.6.29

Weakness: CWE-416 · Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

References