CyberSecBulletin
CVE-2024-44964NVD status: Analyzed

Linux: Missing Release of Memory after Effective Lifetime

Published Updated By the CyberSecBulletin desk

CVE-2024-44964 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 6b289f8d91537ec1e4f9c7b38b31b90d93b1419b, f01032a2ca099ec8d619aaa916c3762aa62495df 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 0.23% 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 6b289f8d91537ec1e4f9c7b38b31b90d93b1419b or f01032a2ca099ec8d619aaa916c3762aa62495df, whichever matches your release line, or a later version.
  2. Update Linux Kernel to 6.10.5 or a later version.

Affected products and versions

VendorProductAffected versionsFixed in
LinuxLinux02cbfba1add5bd9088c7d14c6b93b77a6ea8f3bb up to, but not including, 6b289f8d91537ec1e4f9c7b38b31b90d93b1419b; 02cbfba1add5bd9088c7d14c6b93b77a6ea8f3bb up to, but not including, f01032a2ca099ec8d619aaa916c3762aa62495df; 6.76b289f8d91537ec1e4f9c7b38b31b90d93b1419b, f01032a2ca099ec8d619aaa916c3762aa62495df
LinuxLinux Kernel6.7 up to, but not including, 6.10.5; 6.116.10.5

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.

Official description

In the Linux kernel, the following vulnerability has been resolved: idpf: fix memory leaks and crashes while performing a soft reset The second tagged commit introduced a UAF, as it removed restoring q_vector->vport pointers after reinitializating the structures. This is due to that all queue allocation functions are performed here with the new temporary vport structure and those functions rewrite the backpointers to the vport. Then, this new struct is freed and the pointers start leading to nowhere. But generally speaking, the current logic is very fragile. It claims to be more reliable when the system is low on memory, but in fact, it consumes two times more memory as at the moment of running this function, there are two vports allocated with their queues and vectors. Moreover, it claims to prevent the driver from running into "bad state", but in fact, any error during the rebuild leaves the old vport in the partially allocated state. Finally, if the interface is down when the function is called, it always allocates a new queue set, but when the user decides to enable the interface later on, vport_open() allocates them once again, IOW there's a clear memory leak here. Just don't allocate a new queue set when performing a reset, that solves crashes and memory leaks. Readd the old queue number and reopen the interface on rollback - that solves limbo states when the device is left disabled and/or without HW queues enabled.

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: partial).
  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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