Linux: Use After Free
CVE-2022-49029 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 f2a13196ad41c6c2ab058279dffe6c97292e753a, 798198273bf86673b970b51acdb35e57f42b3fcb, 24b9633f7db7f4809be7053df1d2e117e7c2de10 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 f2a13196ad41c6c2ab058279dffe6c97292e753a or 798198273bf86673b970b51acdb35e57f42b3fcb or 24b9633f7db7f4809be7053df1d2e117e7c2de10 or 7b2b67fe1339389e0bf3c37c7a677a004ac0e4e3, whichever matches your release line, or a later version.
- Update Linux Kernel to 4.9.335 or 4.14.301 or 4.19.268 or 5.4.226, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, f2a13196ad41c6c2ab058279dffe6c97292e753a; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, 798198273bf86673b970b51acdb35e57f42b3fcb; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, 24b9633f7db7f4809be7053df1d2e117e7c2de10; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, 7b2b67fe1339389e0bf3c37c7a677a004ac0e4e3; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, 90907cd4d11351ff76c9a447bcb5db0e264c47cd; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, 45f6e81863747c0d7bc6a95ec51129900e71467a; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, e65cfd1f9cd27d9c27ee5cb88128a9f79f25d863; 57c7c3a0fdea95eddcaeba31e7ca7dfc917682ab up to, but not including, e2a87785aab0dac190ac89be6a9ba955e2c634f2; and 1 more ranges | f2a13196ad41c6c2ab058279dffe6c97292e753a, 798198273bf86673b970b51acdb35e57f42b3fcb, 24b9633f7db7f4809be7053df1d2e117e7c2de10, 7b2b67fe1339389e0bf3c37c7a677a004ac0e4e3, 90907cd4d11351ff76c9a447bcb5db0e264c47cd, 45f6e81863747c0d7bc6a95ec51129900e71467a |
| Linux | Linux Kernel | 2.6.24 up to, but not including, 4.9.335; 4.10 up to, but not including, 4.14.301; 4.15 up to, but not including, 4.19.268; 4.20 up to, but not including, 5.4.226; 5.5 up to, but not including, 5.10.158; 5.11 up to, but not including, 5.15.82; 5.16 up to, but not including, 6.0.12; 6.1 | 4.9.335, 4.14.301, 4.19.268, 5.4.226, 5.10.158, 5.15.82 |
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: hwmon: (ibmpex) Fix possible UAF when ibmpex_register_bmc() fails Smatch report warning as follows: drivers/hwmon/ibmpex.c:509 ibmpex_register_bmc() warn: '&data->list' not removed from list If ibmpex_find_sensors() fails in ibmpex_register_bmc(), data will be freed, but data->list will not be removed from driver_data.bmc_data, then list traversal may cause UAF. Fix by removeing it from driver_data.bmc_data before free().
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
- git.kernel.org/stable/c/24b9633f7db7f4809be7053df1d2e117e7c2de10
- git.kernel.org/stable/c/45f6e81863747c0d7bc6a95ec51129900e71467a
- git.kernel.org/stable/c/798198273bf86673b970b51acdb35e57f42b3fcb
- git.kernel.org/stable/c/7b2b67fe1339389e0bf3c37c7a677a004ac0e4e3
- git.kernel.org/stable/c/90907cd4d11351ff76c9a447bcb5db0e264c47cd
- git.kernel.org/stable/c/e2a87785aab0dac190ac89be6a9ba955e2c634f2
- git.kernel.org/stable/c/e65cfd1f9cd27d9c27ee5cb88128a9f79f25d863
- git.kernel.org/stable/c/f2a13196ad41c6c2ab058279dffe6c97292e753a
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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