Description
kernel/bpf/verifier.c in the Linux kernel through 5.12.1 performs undesirable speculative loads, leading to disclosure of stack content via side-channel attacks, aka CID-801c6058d14a. The specific concern is not protecting the BPF stack area against speculative loads. Also, the BPF stack can contain uninitialized data that might represent sensitive information previously operated on by the kernel.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 5.10.38-1 | — |
| Debian 13 | linux | 5.10.38-1 | — |
| Debian 12 | linux | 5.10.38-1 | — |
| Debian 9 | linux-4.19 | 4.19.194-1~deb9u1 | DLA-2690-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu 20.04 LTS | linux | 5.4.0-77.86 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-aws +1 | 5.4.0-1051.53 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-aws-5.8 | 5.8.0-1038.40~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-azure-5.8 | 5.8.0-1036.38~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-bluefield | 5.4.0-1013.16 | — |
| Ubuntu 20.04 LTS | linux-gcp | 5.4.0-1046.49 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-gcp-5.8 | 5.8.0-1035.37~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-gke | 5.4.0-1046.48 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-gkeop | 5.4.0-1018.19 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.8 | 5.8.0-59.66~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1041.42 | USN-5000-2 |
| Ubuntu 20.04 LTS | linux-oem-5.10 | 5.10.0-1029.30 | USN-4983-1 |
| Ubuntu 20.04 LTS | linux-oracle | 5.4.0-1048.52 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-oracle-5.8 | 5.8.0-1033.34~20.04.1 | USN-4999-1 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1038.41 | USN-5000-1 |
| Ubuntu 20.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv-5.8 | 5.8.0-29.31~20.04.1 | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-151.157 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1109.116 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-aws-5.4 +1 | 5.4.0-1051.53~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1121.134 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-dell300x | 4.15.0-1027.32 | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-4.15 | 4.15.0-1106.120 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-gcp-5.4 | 5.4.0-1046.49~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-gke-5.4 | 5.4.0-1046.48~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-gkeop-5.4 | 5.4.0-1018.19~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-77.86~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1097.99 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1078.86 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-oracle-5.4 | 5.4.0-1048.52~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1038.41~18.04.1 | USN-5000-1 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1092.98 | USN-5018-1 |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1109.118 | USN-5018-1 |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-aws-fips | 5.4.0-1069.73+fips2 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-azure-fips | 5.4.0-1073.76+fips1 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips | 5.4.0-1028.32 | — |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2051.53 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2033.37 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1066.75 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-gcp-fips | 4.15.0-2016.18 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1114.123~20.04.1 | — |
| Ubuntu Pro 16.04 LTS | linux +2 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-aws-hwe | 4.15.0-1109.116~16.04.1 | USN-5018-1 |
| Ubuntu Pro 16.04 LTS | linux-azure | 4.15.0-1121.134~16.04.1 | USN-5018-1 |
| Ubuntu Pro 16.04 LTS | linux-gcp | 4.15.0-1106.120~16.04.1 | USN-5018-1 |
| Ubuntu Pro 16.04 LTS | linux-hwe | 4.15.0-151.157~16.04.1 | USN-5018-1 |
| Ubuntu Pro 16.04 LTS | linux-oracle | 4.15.0-1078.86~16.04.1 | USN-5018-1 |
| Ubuntu Pro 14.04 LTS | linux +2 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1121.134~14.04.1 | USN-5018-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | kernel-rt +12 | 4.18.0-348.rt7.130.el8 | RHSA-2021:4140 |
| RHEL 8 | perf +26 | 4.18.0-348.el8 | RHSA-2021:4356 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | kernel-tools-libs-devel | 4.18.0-348.el8 | ALSA-2021:4356 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.232-176.381 | 1.0-0.amzn2 | ALAS2-2021-1636 |
| Amazon Linux 2 | perf +8 | 4.14.232-176.381.amzn2 | ALAS2-2021-1636 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | 5.10.78.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | perf +19 | 4.18.0-348.el8 | ELSA-2021-4356 |
| Oracle Linux 7 | kernel-uek +4 | 5.4.17-2102.203.5.el8uek | ELSA-2021-9362 |
| Oracle Linux 7 | kernel-uek-container +1 | 5.4.17-2102.203.5.el8 | ELSA-2021-9363 |
| Oracle Linux 7 | perf +3 | 5.4.17-2102.203.5.el7uek | ELSA-2021-9362 |
Advisories 13
- ALSA-2021:4356 Moderate: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:4356 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Oct 2, 2026
- RHSA-2021:4140 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 14, 2026
- USN-5018-1 linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-hwe, linux-kvm, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 29, 2026
- USN-4999-1 linux, linux-aws, linux-aws-5.8, linux-azure, linux-azure-5.8, linux-gcp, linux-gcp-5.8, linux-hwe-5.8, linux-kvm, linux-oracle, linux-oracle-5.8, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4983-1 linux-oem-5.10 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5000-1 linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-gke, linux-gke-5.4, linux-gkeop, linux-gkeop-5.4, linux-hwe-5.4, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-5000-2 linux-kvm vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DLA-2690-1 linux-4.19 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ALAS2-2021-1636 Moderate: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · May 23, 2024
- ELSA-2021-4356 Moderate: kernel security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 16, 2021
- ELSA-2021-9363 Important: Unbreakable Enterprise kernel-container security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 16, 2021
- ELSA-2021-9362 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jul 16, 2021
References
- [oss-security] 20210504 [CVE-2021-31829] Linux kernel protection of stack pointer against speculative pointer arithmetic can be bypassed to leak content of kernel memory mailing-list
- https://github.com/torvalds/linux/commit/801c6058d14a82179a7ee17a4b532cac6fad067f
- FEDORA-2021-9c0276e935 vendor-advisory
- FEDORA-2021-5ad5249c43 vendor-advisory
- FEDORA-2021-7c085ca697 vendor-advisory
- [debian-lts-announce] 20210623 [SECURITY] [DLA 2690-1] linux-4.19 security update mailing-list