CyberSecBulletin
CVE-2024-56775NVD status: Modified

Linux: Missing Release of Memory after Effective Lifetime

CVE-2024-56775 is a high-severity missing release of memory after effective lifetime vulnerability in Linux, with a CVSS 3.1 base score of 7.8 out of 10. It can be exploited with local access to the system by an attacker with a low-privileged account, without any action from a user. The record lists versions 8cb2f6793845f135b28361ba8e96901cae3e5790, 27227a234c1487cb7a684615f0749c455218833a as the first without the flaw, so updating Linux to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.21% chance of exploitation within 30 days, which is low compared with other CVEs.

Next patch cycle

High severity with no evidence of exploitation so far.

What to do

  1. Update Linux to 8cb2f6793845f135b28361ba8e96901cae3e5790 or 27227a234c1487cb7a684615f0749c455218833a, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.12.4 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c up to, but not including, 8cb2f6793845f135b28361ba8e96901cae3e5790; 4562236b3bc0a28aeb6ee93b2d8a849a4c4e1c7c up to, but not including, 27227a234c1487cb7a684615f0749c455218833a; 4.158cb2f6793845f135b28361ba8e96901cae3e5790, 27227a234c1487cb7a684615f0749c455218833a
LinuxLinux Kernelbefore 6.12.46.12.4

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
LocalThe attacker needs local access or must trick a user into running something.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
LowA basic user account is enough.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H. Scored by NVD.

Scoring systemScoreSeverityScored by
CVSS 3.17.8HighNVD
CVSS 3.17.8HighCISA (ADP)

Official description

In the Linux kernel, the following vulnerability has been resolved: drm/amd/display: Fix handling of plane refcount [Why] The mechanism to backup and restore plane states doesn't maintain refcount, which can cause issues if the refcount of the plane changes in between backup and restore operations, such as memory leaks if the refcount was supposed to go down, or double frees / invalid memory accesses if the refcount was supposed to go up. [How] Cache and re-apply current refcount when restoring plane states.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Missing Release of Memory after Effective Lifetime

The product does not sufficiently track and release allocated memory after it has been used, making the memory unavailable for reallocation and reuse.

How developers prevent this class of flaw

  • Choose a language or tool that provides automatic memory management, or makes manual memory management less error-prone. For example, glibc in Linux provides protection against free of invalid pointers. When using Xcode to target OS X or iOS, enable automatic reference counting (ARC). To help correctly and consistently manage memory when programming in C++, consider using a smart pointer class such as std
  • Use an abstraction library to abstract away risky APIs. Not a complete solution.
  • Consider using the Boehm-Demers-Weiser garbage collector (bdwgc), which can help avoid leaks.

More Missing Release of Memory after Effective Lifetime vulnerabilities (CWE-401)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Recent Missing Release of Memory after Effective Lifetime vulnerabilities

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