Description
A flaw was found in the HDLC_PPP module of the Linux kernel in versions before 5.9-rc7. Memory corruption and a read overflow is caused by improper input validation in the ppp_cp_parse_cr function which can cause the system to crash or cause a denial of service. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | kernel | Linux kernel versions before 5.9-rc7 | — |
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 | 5.8.14-1 | — |
| Debian 13 | linux | 5.8.14-1 | — |
| Debian 12 | linux | 5.8.14-1 | — |
| Debian 10 | linux | 4.19.152-1 | DSA-4774-1 |
| Debian 9 | linux | 4.9.240-1 | DLA-2420-1 |
| Debian 9 | linux-4.19 | 4.19.152-1~deb9u1 | DLA-2417-1 |
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 | 5.4.0-56.62 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-aws | 5.4.0-1030.31 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-azure | 5.4.0-1032.33 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-gcp +1 | 5.4.0-1030.32 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-kvm | 5.4.0-1028.29 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-oem-5.6 | 5.6.0-1048.52 | USN-4752-1 |
| Ubuntu 20.04 LTS | linux-raspi | 5.4.0-1023.26 | USN-4658-1 |
| Ubuntu 20.04 LTS | linux-raspi2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-riscv | 5.4.0-37.42 | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-126.129 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1088.93 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-aws-5.4 | 5.4.0-1030.31~18.04.1 | USN-4658-1 |
| Ubuntu 18.04 LTS | linux-azure-4.15 | 4.15.0-1100.111 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-azure-5.4 | 5.4.0-1032.33~18.04.1 | USN-4658-1 |
| Ubuntu 18.04 LTS | linux-dell300x | 4.15.0-1007.11 | — |
| Ubuntu 18.04 LTS | linux-gcp +11 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp-4.15 | 4.15.0-1088.101 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-gcp-5.4 +2 | 5.4.0-1030.32~18.04.1 | USN-4658-1 |
| Ubuntu 18.04 LTS | linux-gkeop-5.4 | 5.4.0-1005.6 | — |
| Ubuntu 18.04 LTS | linux-hwe-5.4 | 5.4.0-56.62~18.04.1 | USN-4658-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1079.81 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1103.114 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1059.65 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-raspi-5.4 | 5.4.0-1023.26~18.04.1 | USN-4658-1 |
| Ubuntu 18.04 LTS | linux-raspi2 +1 | 4.15.0-1074.79 | USN-4660-1 |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1091.100 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux | 4.4.0-197.229 | USN-4657-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1118.132 | USN-4657-1 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1088.93~16.04.1 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1100.111~16.04.1 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1088.101~16.04.1 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-126.129~16.04.1 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1084.93 | USN-4657-1 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1059.65~16.04.1 | USN-4660-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1142.152 | USN-4657-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1146.156 | USN-4657-1 |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro FIPS 20.04 LTS | linux-aws-fips +2 | 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-gcp-fips | 5.4.0-1067.71~20.04.1 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-aws-fips | 4.15.0-2031.32 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-azure-fips | 4.15.0-2013.15 | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips | 4.15.0-1046.53 | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1051.57 | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1082.86 | USN-4657-1 |
| Ubuntu Pro 14.04 LTS | linux-azure | 4.15.0-1100.111~14.04.1 | USN-4660-1 |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-197.229~14.04.1 | USN-4657-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 8 | kernel-rt +12 | 4.18.0-305.rt7.72.el8 | RHSA-2021:1739 |
| RHEL 8 | perf +26 | 4.18.0-305.el8 | RHSA-2021:1578 |
| RHEL 7 | kernel-rt +10 | 3.10.0-1160.11.1.rt56.1145.el7 | RHSA-2020:5441 |
| RHEL 7 | perf +18 | 3.10.0-1160.11.1.el7 | RHSA-2020:5437 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 8 | kernel-tools-libs-devel | 4.18.0-305.el8 | ALSA-2021:1578 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP2 | kernel-azure +2 | 5.3.18-18.24.1 | SUSE-SU-2020:3491-1 |
| SLES 15 SP2 | kernel-default-base | 5.3.18-24.29.2.9.9.3 | SUSE-SU-2020:2980-1 |
| SLES 15 SP2 | kernel-docs +5 | 5.3.18-24.29.2 | SUSE-SU-2020:2980-1 |
| SLES 15 SP1 | kernel-azure +2 | 4.12.14-8.47.1 | SUSE-SU-2020:2906-1 |
| SLES 15 SP1 | kernel-docs +5 | 4.12.14-197.61.1 | SUSE-SU-2020:2905-1 |
| SLES 15 | kernel-docs +6 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.31.1 | SUSE-SU-2020:2907-1 |
| SLES 12 SP5 | kernel-docs +4 | 4.12.14-122.41.1 | SUSE-SU-2020:2904-1 |
| SLES 12 SP4 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
Show 24 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SLES 12 SP3 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
| SLES 12 SP2 | kernel-syms +2 | 4.4.121-92.146.1 | SUSE-SU-2020:3501-1 |
| SLES 12 SP2 | kgraft-patch-SLE12-SP2_Update_38 | 1-3.5.1 | SUSE-SU-2020:3501-1 |
| SLES 11 SP4 | kernel-ec2 +8 | 3.0.101-108.120.1 | SUSE-SU-2021:14630-1 |
| SLES for SAP 15 | kernel-docs +5 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.31.1 | SUSE-SU-2020:2907-1 |
| SLES for SAP 12 SP5 | kernel-syms +2 | 4.12.14-122.41.1 | SUSE-SU-2020:2904-1 |
| SLES for SAP 12 SP4 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SLES for SAP 12 SP3 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SLES for SAP 12 SP3 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
| SLES for SAP 12 SP2 | kernel-syms +2 | 4.4.121-92.146.1 | SUSE-SU-2020:3501-1 |
| SLES for SAP 12 SP2 | kgraft-patch-SLE12-SP2_Update_38 | 1-3.5.1 | SUSE-SU-2020:3501-1 |
| SLE Real Time 12 SP5 | kernel-rt +3 | 4.12.14-10.19.1 | SUSE-SU-2020:2999-1 |
| SLE Live Patching 15 SP2 | kernel-default | 5.3.18-24.29.2 | SUSE-SU-2020:2980-1 |
| SLE Live Patching 15 SP2 | kernel-livepatch-SLE15-SP2_Update_5 | 1-5.3.3 | SUSE-SU-2020:2980-1 |
| SLE Live Patching 15 SP1 | kernel-default | 4.12.14-197.61.1 | SUSE-SU-2020:2905-1 |
| SLE Live Patching 15 SP1 | kernel-livepatch-SLE15-SP1_Update_16 | 1-3.5.1 | SUSE-SU-2020:2905-1 |
| SLE Live Patching 15 | kernel-default | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_21 | 1-1.5.1 | SUSE-SU-2020:3532-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.41.1 | SUSE-SU-2020:2904-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_10 | 1-8.3.1 | SUSE-SU-2020:2904-1 |
| SLE Live Patching 12 SP4 | kernel-default | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SLE Live Patching 12 SP4 | kgraft-patch-SLE12-SP4_Update_17 | 1-6.5.1 | SUSE-SU-2020:3544-1 |
| SLE HPC 15 | kernel-docs +5 | 4.12.14-150.63.1 | SUSE-SU-2020:3532-1 |
| SUSE Real Time Module 15 SP2 | kernel-rt +3 | 5.3.18-13.1 | SUSE-SU-2020:3230-1 |
| SUSE Real Time Module 15 SP1 | kernel-rt +3 | 4.12.14-14.36.1 | SUSE-SU-2020:3014-1 |
| SUSE OpenStack Cloud Crowbar 9 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SUSE OpenStack Cloud Crowbar 8 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SUSE OpenStack Cloud Crowbar 8 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
| SUSE OpenStack Cloud 9 | kernel-syms +2 | 4.12.14-95.65.1 | SUSE-SU-2020:3544-1 |
| SUSE OpenStack Cloud 8 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SUSE OpenStack Cloud 8 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
| SUSE OpenStack Cloud 7 | kernel-syms +2 | 4.4.121-92.146.1 | SUSE-SU-2020:3501-1 |
| SUSE OpenStack Cloud 7 | kgraft-patch-SLE12-SP2_Update_38 | 1-3.5.1 | SUSE-SU-2020:3501-1 |
| SUSE HPE Helion OpenStack 8 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SUSE HPE Helion OpenStack 8 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
| SUSE Enterprise Storage 5 | kernel-syms +2 | 4.4.180-94.135.1 | SUSE-SU-2020:3503-1 |
| SUSE Enterprise Storage 5 | kgraft-patch-SLE12-SP3_Update_36 | 1-4.5.1 | SUSE-SU-2020:3503-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.2 | kernel-debug +5 | 5.3.18-lp152.47.2 | openSUSE-SU-2020:1698-1 |
| openSUSE Leap 15.2 | kernel-default-base | 5.3.18-lp152.50.1.lp152.8.10.1 | openSUSE-SU-2020:2112-1 |
| openSUSE Leap 15.2 | kernel-docs +2 | 5.3.18-lp152.47.1 | openSUSE-SU-2020:1698-1 |
| openSUSE Leap 15.2 | kernel-rt +3 | 5.3.18-lp152.3.5.1 | openSUSE-SU-2021:0242-1 |
| openSUSE Leap 15.1 | kernel-debug +5 | 4.12.14-lp151.28.71.2 | openSUSE-SU-2020:1655-1 |
| openSUSE Leap 15.1 | kernel-docs +2 | 4.12.14-lp151.28.71.1 | openSUSE-SU-2020:1655-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | kernel-livepatch-4.14.200-155.322 | 1.0-0.amzn2 | ALAS2-2020-1520 |
| Amazon Linux 2 | perf +8 | 4.14.200-155.322.amzn2 | ALAS2-2020-1520 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 8 | perf +19 | 4.18.0-305.el8 | ELSA-2021-1578 |
| Oracle Linux 7 | kernel-uek +5 | 4.1.12-124.44.4.el7uek | ELSA-2020-5913, ELSA-2020-5912 |
| Oracle Linux 7 | kernel-uek-tools +3 | 4.14.35-2025.402.2.1.el7uek | ELSA-2020-5913 |
| Oracle Linux 7 | perf +12 | 3.10.0-1160.11.1.el7 | ELSA-2020-5913, ELSA-2020-5437 |
Advisories 35
- ALSA-2021:1578 Important: kernel security, bug fix, and enhancement update AlmaLinux Security Advisories · Oct 29, 2026
- RHSA-2021:1739 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2021:1578 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Aug 7, 2026
- RHSA-2020:5441 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2020:5437 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- USN-4752-1 linux-oem-5.6 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4657-1 linux, linux-aws, linux-azure, linux-kvm, linux-lts-trusty, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4658-1 linux, linux-aws, linux-aws-5.4, linux-azure, linux-azure-5.4, linux-gcp, linux-gcp-5.4, linux-hwe-5.4, linux-kvm, linux-oracle, linux-oracle-5.4, linux-raspi, linux-raspi-5.4 vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-4660-1 linux, linux-aws, linux-aws-hwe, linux-azure, linux-azure-4.15, linux-gcp, linux-gcp-4.15, linux-gke-4.15, linux-hwe, linux-kvm, linux-oem, linux-oracle, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DSA-4774-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2417-1 linux-4.19 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-2420-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- SUSE-SU-2020:3230-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2021:0242-1 Security update for RT kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2980-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2905-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2907-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3544-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3491-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2906-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1698-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3532-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:1655-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3501-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14630-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2904-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:2999-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2020:3014-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2020:2112-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 7, 2025
- SUSE-SU-2020:3503-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · May 2, 2025
- ELSA-2021-1578 Important: kernel security, bug fix, and enhancement update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 25, 2021
- ELSA-2020-5437 Important: kernel security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 16, 2020
- ELSA-2020-5913 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 10, 2020
- ELSA-2020-5912 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 6, 2020
- ALAS2-2020-1520 Important: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Oct 22, 2020
References
- https://bugzilla.redhat.com/show_bug.cgi?id=1879981
- https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=66d42ed8b25b64eb63111a2b8582c5afc8bf1105
- openSUSE-SU-2020:1655 vendor-advisory
- openSUSE-SU-2020:1698 vendor-advisory
- DSA-4774 vendor-advisory
- [debian-lts-announce] 20201028 [SECURITY] [DLA 2417-1] linux-4.19 security update mailing-list
- [debian-lts-announce] 20201030 [SECURITY] [DLA 2420-1] linux security update mailing-list
- [debian-lts-announce] 20201031 [SECURITY] [DLA 2420-2] linux regression update mailing-list
- https://security.netapp.com/advisory/ntap-20201103-0002/
- https://www.starwindsoftware.com/security/sw-20210325-0002/