Description
A denial of service vulnerability was found in n_tty_receive_char_special in drivers/tty/n_tty.c of the Linux kernel. In this flaw a local attacker with a normal user privilege could delay the loop (due to a changing ldata->read_head, and a missing sanity check) and cause a threat to the system availability.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | kernel | kernel 4.18 | — |
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.
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-riscv +1 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | linux-aws +2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP1 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SLES 15 SP1 | kernel-syms +4 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SLES 15 | kernel-docs | 4.12.14-150.72.2 | SUSE-SU-2021:1573-1 |
| SLES 15 | kernel-syms +5 | 4.12.14-150.72.1 | SUSE-SU-2021:1573-1 |
| SLES 12 SP5 | kernel-azure +2 | 4.12.14-16.53.1 | SUSE-SU-2021:1248-1 |
| SLES 12 SP5 | kernel-docs +4 | 4.12.14-122.66.2 | SUSE-SU-2021:1210-1 |
| SLES 12 SP4 | kernel-syms +2 | 4.12.14-95.74.1 | SUSE-SU-2021:1596-1 |
| SLES 12 SP3 | kernel-syms +2 | 4.4.180-94.144.1 | SUSE-SU-2021:1623-1 |
| SLES 12 SP3 | kgraft-patch-SLE12-SP3_Update_39 | 1-4.3.1 | SUSE-SU-2021:1623-1 |
Show 22 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP2 | kernel-syms +2 | 4.4.121-92.155.1 | SUSE-SU-2021:1617-1 |
| SLES for SAP 15 SP1 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SLES for SAP 15 SP1 | kernel-syms +3 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SLES for SAP 15 | kernel-docs | 4.12.14-150.72.2 | SUSE-SU-2021:1573-1 |
| SLES for SAP 15 | kernel-syms +4 | 4.12.14-150.72.1 | SUSE-SU-2021:1573-1 |
| SLES for SAP 12 SP5 | kernel-azure +2 | 4.12.14-16.53.1 | SUSE-SU-2021:1248-1 |
| SLES for SAP 12 SP5 | kernel-syms +2 | 4.12.14-122.66.2 | SUSE-SU-2021:1210-1 |
| SLES for SAP 12 SP4 | kernel-syms +2 | 4.12.14-95.74.1 | SUSE-SU-2021:1596-1 |
| SLES for SAP 12 SP3 | kernel-syms +2 | 4.4.180-94.144.1 | SUSE-SU-2021:1623-1 |
| SLES for SAP 12 SP3 | kgraft-patch-SLE12-SP3_Update_39 | 1-4.3.1 | SUSE-SU-2021:1623-1 |
| SLE Real Time 12 SP5 | kernel-rt +3 | 4.12.14-10.40.1 | SUSE-SU-2021:1266-1 |
| SLE Live Patching 15 SP1 | kernel-default | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SLE Live Patching 15 SP1 | kernel-livepatch-SLE15-SP1_Update_24 | 1-3.3.2 | SUSE-SU-2021:1624-1 |
| SLE Live Patching 15 | kernel-default | 4.12.14-150.72.1 | SUSE-SU-2021:1573-1 |
| SLE Live Patching 15 | kernel-livepatch-SLE15_Update_24 | 1-1.3.1 | SUSE-SU-2021:1573-1 |
| SLE Live Patching 12 SP5 | kernel-default | 4.12.14-122.66.2 | SUSE-SU-2021:1210-1 |
| SLE Live Patching 12 SP5 | kgraft-patch-SLE12-SP5_Update_17 | 1-8.3.2 | SUSE-SU-2021:1210-1 |
| SLE Live Patching 12 SP4 | kernel-default | 4.12.14-95.74.1 | SUSE-SU-2021:1596-1 |
| SLE Live Patching 12 SP4 | kgraft-patch-SLE12-SP4_Update_20 | 1-6.3.1 | SUSE-SU-2021:1596-1 |
| SLE HPC 15 SP1 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SLE HPC 15 SP1 | kernel-syms +3 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SLE HPC 15 | kernel-docs | 4.12.14-150.72.2 | SUSE-SU-2021:1573-1 |
| SLE HPC 15 | kernel-syms +4 | 4.12.14-150.72.1 | SUSE-SU-2021:1573-1 |
| SUSE OpenStack Cloud Crowbar 9 | kernel-syms +2 | 4.12.14-95.74.1 | SUSE-SU-2021:1596-1 |
| SUSE OpenStack Cloud Crowbar 8 | kernel-syms +2 | 4.4.180-94.144.1 | SUSE-SU-2021:1623-1 |
| SUSE OpenStack Cloud Crowbar 8 | kgraft-patch-SLE12-SP3_Update_39 | 1-4.3.1 | SUSE-SU-2021:1623-1 |
| SUSE OpenStack Cloud 9 | kernel-syms +2 | 4.12.14-95.74.1 | SUSE-SU-2021:1596-1 |
| SUSE OpenStack Cloud 8 | kernel-syms +2 | 4.4.180-94.144.1 | SUSE-SU-2021:1623-1 |
| SUSE OpenStack Cloud 8 | kgraft-patch-SLE12-SP3_Update_39 | 1-4.3.1 | SUSE-SU-2021:1623-1 |
| SUSE Manager Server 4.0 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SUSE Manager Server 4.0 | kernel-syms +4 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SUSE Manager Retail Branch Server 4.0 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SUSE Manager Retail Branch Server 4.0 | kernel-syms +3 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SUSE Manager Proxy 4.0 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SUSE Manager Proxy 4.0 | kernel-syms +3 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
| SUSE HPE Helion OpenStack 8 | kernel-syms +2 | 4.4.180-94.144.1 | SUSE-SU-2021:1623-1 |
| SUSE HPE Helion OpenStack 8 | kgraft-patch-SLE12-SP3_Update_39 | 1-4.3.1 | SUSE-SU-2021:1623-1 |
| SUSE Enterprise Storage 6 | kernel-docs | 4.12.14-197.89.3 | SUSE-SU-2021:1624-1 |
| SUSE Enterprise Storage 6 | kernel-syms +3 | 4.12.14-197.89.2 | SUSE-SU-2021:1624-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | kernel-uek +5 | 4.1.12-124.50.2.el7uek | ELSA-2021-9215 |
Advisories 9
- SUSE-SU-2021:1623-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1573-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1210-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1596-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1617-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1624-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1248-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:1266-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2021-9215 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · May 6, 2021