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🛡️ CVE-2023-54019 — kernel

🟠 CVSS 7.8 — High ✅ No Known Exploit NVD
7.8
CVSS Score
0 Low4 Medium7 High9 Critical10

Description

sched/psi: use kernfs polling functions for PSI trigger polling

In the Linux kernel, the following vulnerability has been resolved:

sched/psi: use kernfs polling functions for PSI trigger polling

Destroying psi trigger in cgroup_file_release causes UAF issues when

a cgroup is removed from under a polling process. This is happening

because cgroup removal causes a call to cgroup_file_release while the

actual file is still alive. Destroying the trigger at this point would

also destroy its waitqueue head and if there is still a polling process

on that file accessing the waitqueue, it will step on the freed pointer:

do_select

vfs_poll

do_rmdir

cgroup_rmdir

kernfs_drain_open_files

cgroup_file_release

cgroup_pressure_release

psi_trigger_destroy

wake_up_pollfree(&t->event_wait)

// vfs_poll is unblocked

synchronize_rcu

kfree(t)

poll_freewait -> UAF access to the trigger's waitqueue head

Patch [1] fixed this issue for epoll() case using wake_up_pollfree(),

however the same issue exists for synchronous poll() case.

The root cause of this issue is that the lifecycles of the psi trigger's

waitqueue and of the file associated with the trigger are different. Fix

this by using kernfs_generic_poll function when polling on cgroup-specific

psi triggers. It internally uses kernfs_open_node->poll waitqueue head

with its lifecycle tied to the file's lifecycle. This also renders the

fix in [1] obsolete, so revert it.

[1] commit c2dbe32d5db5 ("sched/psi: Fix use-after-free in ep_remove_wait_queue()")

How this vulnerability can be exploited

This issue can be reached with local access to the system, attack complexity is low, an attacker needs low-level privileges on the target. No user interaction is required. The scope is unchanged, so the impact stays within the vulnerable component. Rated impact: confidentiality high, integrity high, availability high.

CVSS metrics in full

The score comes from this vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

  • Attack vector: Local — a local account, shell or session on the host is needed.
  • Attack complexity: Low — the attack works reliably, with no preparation.
  • Privileges required: Low — an ordinary user account is enough.
  • User interaction: None — nobody has to be tricked into anything.
  • Scope: Unchanged — the damage stays inside the vulnerable component.
  • Confidentiality impact: High — total loss, or loss the attacker controls.
  • Integrity impact: High — total loss, or loss the attacker controls.
  • Availability impact: High — total loss, or loss the attacker controls.

Affected software

CVE-2023-54019 is recorded against 2 packages.

  • kernel (from 6.2.0 up to 6.4.7)
  • unknown

Timeline and source

Published on 24 December 2025 and last revised on 12 August 2026. No public exploit is currently recorded for this entry. Record sourced from NVD.

References

git.kernel.org (Web)
git.kernel.org (Web)
git.kernel.org (Web)
github.com (Advisory)
nvd.nist.gov (Advisory)
git.kernel.org (Package)

Other advisories for this package

kernel has other advisories on record. If you are patching this one, these are worth checking on the same host:

Details

Severity High
CVSS Score 7.8
CVSS Vector CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CWE N/A
Public Exploit ✅ No
Source NVD
Published 2025-12-24
Updated 2026-08-20
Modified 2026-08-12
Fix URL N/A

Affected Packages

Software From version Fixed in
kernel 6.2.0 6.4.7
unknown — —

Similar Threats

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