Description
An issue was discovered in the Linux kernel before 5.9.3. io_uring takes a non-refcounted reference to the files_struct of the process that submitted a request, causing execve() to incorrectly optimize unshare_fd(), aka CID-0f2122045b94.
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 | 5.9.6-1 | — |
| Debian 13 | linux | 5.9.6-1 | — |
| Debian 12 | linux | 5.9.6-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-hwe-5.8 | 5.8.0-34.37~20.04.2 | USN-4678-1 |
| Ubuntu 20.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +12 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Advisories 1
- USN-4678-1 linux, linux-hwe-5.8, linux-aws, linux-azure, linux-gcp, linux-kvm, linux-oracle, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026