fkie_cve-2022-50307
Vulnerability from fkie_nvd
Published
2025-09-15 15:15
Modified
2025-09-15 15:22
Severity ?
Summary
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.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/cio: fix out-of-bounds access on cio_ignore free\n\nThe channel-subsystem-driver scans for newly available devices whenever\ndevice-IDs are removed from the cio_ignore list using a command such as:\n\n echo free \u003e/proc/cio_ignore\n\nSince an I/O device scan might interfer with running I/Os, commit\n172da89ed0ea (\"s390/cio: avoid excessive path-verification requests\")\nintroduced an optimization to exclude online devices from the scan.\n\nThe newly added check for online devices incorrectly assumes that\nan I/O-subchannel\u0027s drvdata points to a struct io_subchannel_private.\nFor devices that are bound to a non-default I/O subchannel driver, such\nas the vfio_ccw driver, this results in an out-of-bounds read access\nduring each scan.\n\nFix this by changing the scan logic to rely on a driver-independent\nonline indication. For this we can use struct subchannel-\u003econfig.ena,\nwhich is the driver\u0027s requested subchannel-enabled state. Since I/Os\ncan only be started on enabled subchannels, this matches the intent\nof the original optimization of not scanning devices where I/O might\nbe running."
}
],
"id": "CVE-2022-50307",
"lastModified": "2025-09-15T15:22:27.090",
"metrics": {},
"published": "2025-09-15T15:15:42.377",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/0e501fd0f38e42304bfa0d46a812d93f80294a87"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/106ab66cf5467726ca5ead51623043d37c06820a"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1b6074112742f65ece71b0f299ca5a6a887d2db6"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Awaiting Analysis"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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