Linux: Use After Free
CVE-2024-49876 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 272b0e78874586d6ccae04079d75b27b47705544, 421c74670b0f9d5c007f1276d3647aa58f407fde, 2d2be279f1ca9e7288282d4214f16eea8a727cdb 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 0.24% 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 272b0e78874586d6ccae04079d75b27b47705544 or 421c74670b0f9d5c007f1276d3647aa58f407fde or 2d2be279f1ca9e7288282d4214f16eea8a727cdb, whichever matches your release line, or a later version.
- Update Linux Kernel to 6.10.14 or 6.11.3, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | dd08ebf6c3525a7ea2186e636df064ea47281987 up to, but not including, 272b0e78874586d6ccae04079d75b27b47705544; dd08ebf6c3525a7ea2186e636df064ea47281987 up to, but not including, 421c74670b0f9d5c007f1276d3647aa58f407fde; dd08ebf6c3525a7ea2186e636df064ea47281987 up to, but not including, 2d2be279f1ca9e7288282d4214f16eea8a727cdb; 6.8 | 272b0e78874586d6ccae04079d75b27b47705544, 421c74670b0f9d5c007f1276d3647aa58f407fde, 2d2be279f1ca9e7288282d4214f16eea8a727cdb |
| Linux | Linux Kernel | 6.8 up to, but not including, 6.10.14; 6.11 up to, but not including, 6.11.3; 6.12 | 6.10.14, 6.11.3 |
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 system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 3.1 | 7.8 | High | CNA |
| CVSS 3.1 | 7.8 | High | NVD |
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/xe: fix UAF around queue destruction We currently do stuff like queuing the final destruction step on a random system wq, which will outlive the driver instance. With bad timing we can teardown the driver with one or more work workqueue still being alive leading to various UAF splats. Add a fini step to ensure user queues are properly torn down. At this point GuC should already be nuked so queue itself should no longer be referenced from hw pov. v2 (Matt B) - Looks much safer to use a waitqueue and then just wait for the xa_array to become empty before triggering the drain. (cherry picked from commit 861108666cc0e999cffeab6aff17b662e68774e3)
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
- 7.0 High severity
- 7.0 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
- 7.8 High severity
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