Linux: Out-of-bounds Read
CVE-2022-50307 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 0e501fd0f38e42304bfa0d46a812d93f80294a87, 106ab66cf5467726ca5ead51623043d37c06820a, 1b6074112742f65ece71b0f299ca5a6a887d2db6 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 0e501fd0f38e42304bfa0d46a812d93f80294a87 or 106ab66cf5467726ca5ead51623043d37c06820a or 1b6074112742f65ece71b0f299ca5a6a887d2db6, whichever matches your release line, or a later version.
- Update Linux Kernel to 5.15.78 or 6.0.7, whichever matches your release line, or a later version.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Linux | Linux | 172da89ed0eaf9d9348f5decb86ad04c624b39d1 up to, but not including, 0e501fd0f38e42304bfa0d46a812d93f80294a87; 172da89ed0eaf9d9348f5decb86ad04c624b39d1 up to, but not including, 106ab66cf5467726ca5ead51623043d37c06820a; 172da89ed0eaf9d9348f5decb86ad04c624b39d1 up to, but not including, 1b6074112742f65ece71b0f299ca5a6a887d2db6; 5.15 | 0e501fd0f38e42304bfa0d46a812d93f80294a87, 106ab66cf5467726ca5ead51623043d37c06820a, 1b6074112742f65ece71b0f299ca5a6a887d2db6 |
| Linux | Linux Kernel | 5.15.1 up to, but not including, 5.15.78; 5.16 up to, but not including, 6.0.7; 5.15; 6.1 | 5.15.78, 6.0.7 |
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: s390/cio: fix out-of-bounds access on cio_ignore free The channel-subsystem-driver scans for newly available devices whenever device-IDs are removed from the cio_ignore list using a command such as: echo free >/proc/cio_ignore Since an I/O device scan might interfer with running I/Os, commit 172da89ed0ea ("s390/cio: avoid excessive path-verification requests") introduced an optimization to exclude online devices from the scan. The newly added check for online devices incorrectly assumes that an I/O-subchannel's drvdata points to a struct io_subchannel_private. For devices that are bound to a non-default I/O subchannel driver, such as the vfio_ccw driver, this results in an out-of-bounds read access during each scan. Fix this by changing the scan logic to rely on a driver-independent online indication. For this we can use struct subchannel->config.ena, which is the driver's requested subchannel-enabled state. Since I/Os can only be started on enabled subchannels, this matches the intent of the original optimization of not scanning devices where I/O might be running.
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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