Description
The time subsystem in the Linux kernel through 4.9.9, when CONFIG_TIMER_STATS is enabled, allows local users to discover real PID values (as distinguished from PID values inside a PID namespace) by reading the /proc/timer_list file, related to the print_timer function in kernel/time/timer_list.c and the __timer_stats_timer_set_start_info function in kernel/time/timer.c.
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 | 4.9.13-1 | — |
| Debian 13 | linux | 4.9.13-1 | — |
| Debian 12 | linux | 4.9.13-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | linux-vmware | No fix yet | — |
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-azure-fde | No fix yet | — |
| Ubuntu 18.04 LTS | linux-snapdragon | 4.15.0-1053.57 | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux | 4.4.0-208.240 | USN-4904-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1126.140 | USN-4904-1 |
| Ubuntu 16.04 LTS | linux-gcp | 4.13.0-1002.5 | — |
| Ubuntu 16.04 LTS | linux-hwe | 4.13.0-32.35~16.04.1 | — |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1091.100 | USN-4904-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1150.161 | USN-4904-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1154.164 | USN-4904-1 |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1060.66 | — |
| Ubuntu Pro 14.04 LTS | linux | 3.13.0-218.269 | USN-8924-1 |
| Ubuntu Pro 14.04 LTS | linux-aws | 4.4.0-1090.94 | USN-4904-1 |
| Ubuntu Pro 14.04 LTS | linux-lts-xenial | 4.4.0-208.240~14.04.1 | USN-4904-1 |
Advisories 3
- WID-SEC-2026-3895 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 13, 2026
- USN-8924-1 linux vulnerabilities Ubuntu Security Notices (USN) · Oct 13, 2026
- USN-4904-1 linux, linux-aws, linux-kvm, linux-lts-xenial, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026