CVE-2024-43869

MEDIUM EPSS 11.3%
Published Aug 21, 20241y ago · Modified Jun 17, 20261w ago
5.5 CVSS 3.1
Medium
Find Similar
Published Aug 21, 2024 1y ago
Last Modified Jun 17, 2026 1w ago

Description

In the Linux kernel, the following vulnerability has been resolved: perf: Fix event leak upon exec and file release The perf pending task work is never waited upon the matching event release. In the case of a child event, released via free_event() directly, this can potentially result in a leaked event, such as in the following scenario that doesn't even require a weak IRQ work implementation to trigger: schedule() prepare_task_switch() =======> <NMI> perf_event_overflow() event->pending_sigtrap = ... irq_work_queue(&event->pending_irq) <======= </NMI> perf_event_task_sched_out() event_sched_out() event->pending_sigtrap = 0; atomic_long_inc_not_zero(&event->refcount) task_work_add(&event->pending_task) finish_lock_switch() =======> <IRQ> perf_pending_irq() //do nothing, rely on pending task work <======= </IRQ> begin_new_exec() perf_event_exit_task() perf_event_exit_event() // If is child event free_event() WARN(atomic_long_cmpxchg(&event->refcount, 1, 0) != 1) // event is leaked Similar scenarios can also happen with perf_event_remove_on_exec() or simply against concurrent perf_event_release(). Fix this with synchonizing against the possibly remaining pending task work while freeing the event, just like is done with remaining pending IRQ work. This means that the pending task callback neither need nor should hold a reference to the event, preventing it from ever beeing freed.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
11.3% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-401

Affected Products 7

VendorProductVersionRange
linuxlinux_kernel*≥5.15.84  –  <5.15.165
linuxlinux_kernel*≥6.0.14  –  <6.1
linuxlinux_kernel*≥6.1.1  –  <6.1.103
linuxlinux_kernel*≥6.2  –  <6.6.44
linuxlinux_kernel*≥6.7  –  <6.10.3
linuxlinux_kernel6.1any
linuxlinux_kernel6.1any

References 6

  • git.kernel.org https://git.kernel.org/stable/c/104e258a004037bc7dba9f6085c71dad6af57ad4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3a5465418f5fd970e86a86c7f4075be262682840
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9ad46f1fef421d43cdab3a7d1744b2f43b54dae0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ed2c202dac55423a52d7e2290f2888bf08b8ee99
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f34d8307a73a18de5320fcc6f40403146d061891
    Patch
  • lists.debian.org https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/104e258a004037bc7dba9f6085c71dad6af57ad4
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/3a5465418f5fd970e86a86c7f4075be262682840
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/9ad46f1fef421d43cdab3a7d1744b2f43b54dae0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/ed2c202dac55423a52d7e2290f2888bf08b8ee99
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f34d8307a73a18de5320fcc6f40403146d061891
    Patch