Linux: Use After Free
CVE-2022-49359 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 8c8e8cc91a6ffc79865108279a74fd57d9070a17, 472dd7ea5e19a1aeabf1711ddc756777e05ee7c2, 6e516faf04317db2c46cbec4e3b78b4653a5b109 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 0.27% 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 8c8e8cc91a6ffc79865108279a74fd57d9070a17 or 472dd7ea5e19a1aeabf1711ddc756777e05ee7c2 or 6e516faf04317db2c46cbec4e3b78b4653a5b109 or 5.11, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.11 or 5.14 or 5.17.15 or 5.18.4, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 7fdc48cc63a30fa3480d18bdd8c5fff2b9b15212 up to, but not including, 8c8e8cc91a6ffc79865108279a74fd57d9070a17; 7fdc48cc63a30fa3480d18bdd8c5fff2b9b15212 up to, but not including, 472dd7ea5e19a1aeabf1711ddc756777e05ee7c2; 7fdc48cc63a30fa3480d18bdd8c5fff2b9b15212 up to, but not including, 6e516faf04317db2c46cbec4e3b78b4653a5b109; c29485e34e63198dca6289639aa711f99d88e76e; 626adede2642f00c8918999a2451bd0a644ab9b7; cf461fa9250a634e8afc4433d82ae0decea8136e; 5.10.67 up to, but not including, 5.11; 5.13.19 up to, but not including, 5.14; and 2 more ranges | 8c8e8cc91a6ffc79865108279a74fd57d9070a17, 472dd7ea5e19a1aeabf1711ddc756777e05ee7c2, 6e516faf04317db2c46cbec4e3b78b4653a5b109, 5.11, 5.14, 5.15 |
| Linux | Linux Kernel | 5.10.67 up to, but not including, 5.11; 5.13.19 up to, but not including, 5.14; 5.14.6 up to, but not including, 5.17.15; 5.18 up to, but not including, 5.18.4; 5.19 | 5.11, 5.14, 5.17.15, 5.18.4 |
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 CISA (ADP).
Official description
In the Linux kernel, the following vulnerability has been resolved: drm/panfrost: Job should reference MMU not file_priv For a while now it's been allowed for a MMU context to outlive it's corresponding panfrost_priv, however the job structure still references panfrost_priv to get hold of the MMU context. If panfrost_priv has been freed this is a use-after-free which I've been able to trigger resulting in a splat. To fix this, drop the reference to panfrost_priv in the job structure and add a direct reference to the MMU structure which is what's actually needed.
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: total).
- 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
- 7.8 High severity
- 7.8 High severity
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