7.8

CVE-2025-40201: kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths

Deferred
AliasesUBUNTU-CVE-2025-40201DEBIAN-CVE-2025-40201
Published 12-11-2025Last modified 15-10-2026

Vulnerability summary

CVE-2025-40201 is a high (CVSS 7.8) vulnerability in linux. EPSS estimates a 0.15% chance of exploitation in the next 30 days, higher than 4.4% of scored vulnerabilities.

Priority
Routine

Not severe (CVSS 7.8, local access); no exploitation reported by the 5 checked sources

Source freshness unavailable

How is this decided?
CVSS score
7.8/10
010
High · v3.1 (CVE.org)
EPSS score
0.15%
0%100%
Low · +0.01 pp in 30 days
KEVNot listedNot listed by any tracked catalog.
RansomwareNot flaggedNo ransomware use recorded.
Public exploits0No public exploits recorded

Advisory lineage

Upstream 0 · Downstream 26 · Related 25
DLA-4379-1OPENSUSE-SU-2025:20172-1SUSE-SU-2026:0962-1SUSE-SU-2026:1081-1SUSE-SU-2026:20012-1SUSE-SU-2026:20015-1

Timeline

  1. 12-11-2025
    PublishedVulnerability first disclosed.
  2. 15-10-2026
    Last modifiedVulnerability information updated.

Description

In the Linux kernel, the following vulnerability has been resolved: kernel/sys.c: fix the racy usage of task_lock(tsk->group_leader) in sys_prlimit64() paths The usage of task_lock(tsk->group_leader) in sys_prlimit64()->do_prlimit() path is very broken. sys_prlimit64() does get_task_struct(tsk) but this only protects task_struct itself. If tsk != current and tsk is not a leader, this process can exit/exec and task_lock(tsk->group_leader) may use the already freed task_struct. Another problem is that sys_prlimit64() can race with mt-exec which changes ->group_leader. In this case do_prlimit() may take the wrong lock, or (worse) ->group_leader may change between task_lock() and task_unlock(). Change sys_prlimit64() to take tasklist_lock when necessary. This is not nice, but I don't see a better fix for -stable.

CVSS metrics

5 scores · 4 sources · 2 versions

EPSS trend

Probability

0.15%

Chance of exploitation in the next 30 days

Percentile

4%

Versus all other CVEs

30-day change

Increase +0.01 pp

From 0.14% on 04-10-2026

04-10-202603-11-2026

Known exploited

Compare KEV catalogs
CISA KEV

Not in the CISA KEV catalog.

ENISA CNW

Not in the ENISA CNW catalog.

CIRCL

Not in the CIRCL catalog.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

No weakness data has been published for this record.

Affected systems

Version check

Known conditions: local access, low-privilege account, no user interaction (CVSS vector). Other conditions: not stated in public data.

Ubuntu127 products
  • linux< 6.8.0-106.106 | < 6.17.0-14.14
  • linux-allwinner-5.19All versions (No fix recorded)
  • linux-aws< 6.8.0-1050.53 | < 6.17.0-1007.7
  • linux-aws-5.0All versions (No fix recorded)
  • linux-aws-5.11All versions (No fix recorded)
Debian1 product
  • linux< 6.1.158-1 | < 6.12.57-1 | < 6.17.6-1
Linux1 product
  • linux≥ 18c91bb2d87268d23868bf13508f5bc9cf04e89a, < 1bc0d9315ef5296abb2c9fd840336255850ded18 | ≥ 18c91bb2d87268d23868bf13508f5bc9cf04e89a, < 132f827e7bac7373e1522e89709d70b43cae5342 | ≥ 18c91bb2d87268d23868bf13508f5bc9cf04e89a, < 19b45c84bd9fd42fa97ff80c6350d604cb871c75 | ≥ 18c91bb2d87268d23868bf13508f5bc9cf04e89a, < 6796412decd2d8de8ec708213bbc958fab72f143 | ≥ 18c91bb2d87268d23868bf13508f5bc9cf04e89a, < a15f37a40145c986cdf289a4b88390f35efdecc4 | 5.18

3 vendors · 129 products

References

25 links
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