# CVE-2021-20321: bpftool: The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: I... CVE-2021-20321 is fixed in 38 products on 1 platform, first by RHSA-2021:5227, released December 21, 2021. It is not reported as exploited. Patch Radar priority: Routine. - Web page: https://patchblox.com/security/cve/CVE-2021-20321 - Priority: Routine - CVSS: 5.5 (Moderate) - EPSS: 0.0022 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Dec 21, 2021 ## Description The kernel packages contain the Linux kernel, the core of any Linux operating system. Security Fix(es): * kernel: In Overlayfs missing a check for a negative dentry before calling vfs_rename() (CVE-2021-20321) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Bug Fix(es): * panic while breaking a lease/delegation after user mode helper invocation (BZ#2010333) * The ASR driver is causing a system crash in RHEL8.4 compared to RHEL8.3 due to kernel changes (BZ#2016384) * RHEL8: DFS provided SMB shares are not accessible following unprivileged access (BZ#2017177) * Avoid hitting the rtnl_trylock/restart_syscall logic in net-sysfs when possible (BZ#2021165) * RHEL8: x86/Kconfig: Do not enable AMD_MEM_ENCRYPT_ACTIVE_BY_DEFAULT (BZ#2024678) * RHEL8.4-[Regression][P10][DD2.0][Rainier/Denali] - system crashed while offlining and onlining cores (BZ#2026450) ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | bpftool RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | bpftool ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel rocky 8 | 0:4.18.0-348.7.1.el8_5 | [RLSA-2021:5227](https://patchblox.com/security/data/fix/linux/rlsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-abi-stablelists RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-abi-stablelists ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-core RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-core ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-cross-headers RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-cross-headers ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-debug RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-debug ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-debug-core RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-debug-core ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-debug-devel RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-debug-devel ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-debug-modules RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-debug-modules ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-debug-modules-extra RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-debug-modules-extra ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-devel RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-devel ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-doc RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-doc ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-headers ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-modules RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-modules ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-modules-extra RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-modules-extra ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-rt RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt rocky 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RLSA-2021:5241](https://patchblox.com/security/data/fix/linux/rlsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-core RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug-core RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug-devel RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug-kvm RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug-modules RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-debug-modules-extra RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-devel RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-kvm RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-modules RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-rt-modules-extra RHEL 8 | 0:4.18.0-348.7.1.rt7.137.el8_5 | [RHSA-2021:5241](https://patchblox.com/security/data/fix/linux/rhsa-2021-5241.md) | Dec 21, 2021 | | Linux | kernel-tools RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-tools ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-tools-libs RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-tools-libs ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-tools-libs-devel RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-tools-libs-devel almalinux 8 | 4.18.0-348.7.1.el8_5 | [ALSA-2021:5227](https://patchblox.com/security/data/fix/linux/alsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-tools-libs-devel ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | kernel-zfcpdump RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-zfcpdump-core RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-zfcpdump-devel RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-zfcpdump-modules RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | kernel-zfcpdump-modules-extra RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | linux Debian 12.15 (bookworm) | 5.14.12-1 | [DEBIAN-CVE-2021-20321](https://patchblox.com/security/data/fix/linux/debian-cve-2021-20321.md) | Feb 18, 2022 | | Linux | linux Debian 13.5 (trixie) | 5.14.12-1 | [DEBIAN-CVE-2021-20321](https://patchblox.com/security/data/fix/linux/debian-cve-2021-20321.md) | Feb 18, 2022 | | Linux | linux Debian 14 | 5.14.12-1 | [DEBIAN-CVE-2021-20321](https://patchblox.com/security/data/fix/linux/debian-cve-2021-20321.md) | Feb 18, 2022 | | Linux | perf RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | perf ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | | Linux | python3-perf RHEL 8 | 0:4.18.0-348.7.1.el8_5 | [RHSA-2021:5227](https://patchblox.com/security/data/fix/linux/rhsa-2021-5227.md) | Dec 21, 2021 | | Linux | python3-perf ol 8 | 0:4.18.0-348.7.1.el8_5 | [ELSA-2021-5227](https://patchblox.com/security/data/fix/linux/elsa-2021-5227.md) | Dec 22, 2021 | --- Data as of 2026-11-09T19:38:12Z UTC. 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