Linux: Out-of-bounds Read
CVE-2022-50239 is a high-severity out-of-bounds read vulnerability in Linux, with a CVSS 3.1 base score of 7.1 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 794ded0bc461287a268bed21fea2eebb6e5d232c, 14d260f94ff89543597ffea13db8b277a810e08e, b74ee4e301ca01e431e240c046173332966e2431 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 0.16% 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 794ded0bc461287a268bed21fea2eebb6e5d232c or 14d260f94ff89543597ffea13db8b277a810e08e or b74ee4e301ca01e431e240c046173332966e2431 or 01039fb8e90c9cb684430414bff70cea9eb168c5, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.10.152 or 5.15.76 or 6.0.6, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | a8811ec764f95a04ba82f6f457e28c5e9e36e36b up to, but not including, 794ded0bc461287a268bed21fea2eebb6e5d232c; a8811ec764f95a04ba82f6f457e28c5e9e36e36b up to, but not including, 14d260f94ff89543597ffea13db8b277a810e08e; a8811ec764f95a04ba82f6f457e28c5e9e36e36b up to, but not including, b74ee4e301ca01e431e240c046173332966e2431; a8811ec764f95a04ba82f6f457e28c5e9e36e36b up to, but not including, 01039fb8e90c9cb684430414bff70cea9eb168c5; 5.7 | 794ded0bc461287a268bed21fea2eebb6e5d232c, 14d260f94ff89543597ffea13db8b277a810e08e, b74ee4e301ca01e431e240c046173332966e2431, 01039fb8e90c9cb684430414bff70cea9eb168c5 |
| Linux | Linux Kernel | 5.7 up to, but not including, 5.10.152; 5.11 up to, but not including, 5.15.76; 5.16 up to, but not including, 6.0.6; 6.1 | 5.10.152, 5.15.76, 6.0.6 |
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
- NoneNothing can be modified.
- 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:N/A:H. Scored by NVD.
Official description
In the Linux kernel, the following vulnerability has been resolved: cpufreq: qcom: fix writes in read-only memory region This commit fixes a kernel oops because of a write in some read-only memory: [ 9.068287] Unable to handle kernel write to read-only memory at virtual address ffff800009240ad8 ..snip.. [ 9.138790] Internal error: Oops: 9600004f [#1] PREEMPT SMP ..snip.. [ 9.269161] Call trace: [ 9.276271] __memcpy+0x5c/0x230 [ 9.278531] snprintf+0x58/0x80 [ 9.282002] qcom_cpufreq_msm8939_name_version+0xb4/0x190 [ 9.284869] qcom_cpufreq_probe+0xc8/0x39c ..snip.. The following line defines a pointer that point to a char buffer stored in read-only memory: char *pvs_name = "speedXX-pvsXX-vXX"; This pointer is meant to hold a template "speedXX-pvsXX-vXX" where the XX values get overridden by the qcom_cpufreq_krait_name_version function. Since the template is actually stored in read-only memory, when the function executes the following call we get an oops: snprintf(*pvs_name, sizeof("speedXX-pvsXX-vXX"), "speed%d-pvs%d-v%d", speed, pvs, pvs_ver); To fix this issue, we instead store the template name onto the stack by using the following syntax: char pvs_name_buffer[] = "speedXX-pvsXX-vXX"; Because the `pvs_name` needs to be able to be assigned to NULL, the template buffer is stored in the pvs_name_buffer and not under the pvs_name variable.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Out-of-bounds Read
The product reads data past the end, or before the beginning, of the intended buffer.
How developers prevent this class of flaw
- Use a language that provides appropriate memory abstractions.
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 Out-of-bounds Read vulnerabilities
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
- 7.1 High severity
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