Linux: Use After Free
CVE-2024-44932 is a high-severity use after free 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 3cde714b0e77206ed1b5cf31f28c18ba9ae946fd, 290f1c033281c1a502a3cd1c53c3a549259c491f 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.
High severity with no evidence of exploitation so far.
What to do
- Update Linux to 3cde714b0e77206ed1b5cf31f28c18ba9ae946fd or 290f1c033281c1a502a3cd1c53c3a549259c491f, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.10.5 or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 1c325aac10a82f11410da8a2bf35e3e410a42751 up to, but not including, 3cde714b0e77206ed1b5cf31f28c18ba9ae946fd; 1c325aac10a82f11410da8a2bf35e3e410a42751 up to, but not including, 290f1c033281c1a502a3cd1c53c3a549259c491f; 6.7 | 3cde714b0e77206ed1b5cf31f28c18ba9ae946fd, 290f1c033281c1a502a3cd1c53c3a549259c491f |
| Linux | Linux Kernel | 6.7 up to, but not including, 6.10.5; 6.11 | 6.10.5 |
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 UAFs when destroying the queues The second tagged commit started sometimes (very rarely, but possible) throwing WARNs from net/core/page_pool.c:page_pool_disable_direct_recycling(). Turned out idpf frees interrupt vectors with embedded NAPIs *before* freeing the queues making page_pools' NAPI pointers lead to freed memory before these pools are destroyed by libeth. It's not clear whether there are other accesses to the freed vectors when destroying the queues, but anyway, we usually free queue/interrupt vectors only when the queues are destroyed and the NAPIs are guaranteed to not be referenced anywhere. Invert the allocation and freeing logic making queue/interrupt vectors be allocated first and freed last. Vectors don't require queues to be present, so this is safe. Additionally, this change allows to remove that useless queue->q_vector pointer cleanup, as vectors are still valid when freeing the queues (+ both are freed within one function, so it's not clear why nullify the pointers at all).
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Use After Free
The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory belongs to the code that operates on the new pointer.
How developers prevent this class of flaw
- Choose a language that provides automatic memory management.
- When freeing pointers, be sure to set them to NULL once they are freed. However, the utilization of multiple or complex data structures may lower the usefulness of this strategy.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Patches and release notes
Recent Use After Free vulnerabilities
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.0 High severity
- 7.8 High severity
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