Description
A flaw was found in the way memory resources were freed in the unix_stream_recvmsg function in the Linux kernel when a signal was pending. This flaw allows an unprivileged local user to crash the system by exhausting available memory. The highest threat from this vulnerability is to system availability.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | kernel | Linux kernel 4.5-rc3 | — |
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 | 4.4.4-1 | — |
| Debian 13 | linux | 4.4.4-1 | — |
| Debian 12 | linux | 4.4.4-1 | — |
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 | — |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1010.13 | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 14.04 LTS | linux +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kernel-rt +10 | 3.10.0-1160.21.1.rt56.1158.el7 | RHSA-2021:0857 |
| RHEL 7 | perf +18 | 3.10.0-1160.21.1.el7 | RHSA-2021:0856 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 ELS | perf +13 | 2.6.32-754.39.1.el6 | RHSA-2021:1288 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SLES 12 SP3 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SLES 12 SP2 | kernel-syms +2 | 4.4.121-92.161.1 | SUSE-SU-2021:3929-1 |
| SLES 11 SP4 | kernel-ec2 +8 | 3.0.101-108.132.1 | SUSE-SU-2021:14849-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SLES for SAP 12 SP3 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud Crowbar 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud Crowbar 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE HPE Helion OpenStack 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE HPE Helion OpenStack 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | perf +12 | 3.10.0-1160.21.1.el7 | ELSA-2021-0856 |
Advisories 7
- RHSA-2021:0857 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Aug 26, 2026
- RHSA-2021:0856 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Aug 26, 2026
- RHSA-2021:1288 Red Hat Security Advisory: kernel security and bug fix update Red Hat Security Advisories (RHSA) · Jul 31, 2026
- SUSE-SU-2021:3929-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3935-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:14849-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2021-0856 Important: kernel security and bug fix update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 17, 2021