Description
A flaw incorrect umask during file or directory modification in the Linux kernel NFS (network file system) functionality was found in the way user create and delete object using NFSv4.2 or newer if both simultaneously accessing the NFS by the other process that is not using new NFSv4.2. A user with access to the NFS could use this flaw to starve the resources causing denial of service.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| — | kernel | before kernel 4.17-rc1 | — |
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 | 4.16.5-1 | — |
| Debian 13 | linux | 4.16.5-1 | — |
| Debian 12 | linux | 4.16.5-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-riscv +1 | No fix yet | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-23.25 | — |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1010.10 | — |
| Ubuntu 18.04 LTS | linux-gcp +12 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1011.11 | — |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1012.13 | — |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1013.13~16.04.2 | — |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1014.14~16.04.1 | — |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-24.26~16.04.1 | — |
| 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 +3 | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | kernel-rt +10 | 3.10.0-1160.15.2.rt56.1152.el7 | RHSA-2021:0338 |
| RHEL 7 | perf +18 | 3.10.0-1160.15.2.el7 | RHSA-2021:0336 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | perf +12 | 3.10.0-1160.15.2.el7 | ELSA-2021-0336 |
Advisories 3
- RHSA-2021:0336 Red Hat Security Advisory: kernel security, bug fix, and enhancement update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- RHSA-2021:0338 Red Hat Security Advisory: kernel-rt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- ELSA-2021-0336 Moderate: kernel security, bug fix, and enhancement update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 3, 2021