ghsa-g9gr-r3wp-c95w
Vulnerability from github
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.
{
"affected": [],
"aliases": [
"CVE-2022-50307"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2025-09-15T15:15:42Z",
"severity": null
},
"details": "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": "GHSA-g9gr-r3wp-c95w",
"modified": "2025-09-15T15:31:26Z",
"published": "2025-09-15T15:31:26Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2022-50307"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0e501fd0f38e42304bfa0d46a812d93f80294a87"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/106ab66cf5467726ca5ead51623043d37c06820a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/1b6074112742f65ece71b0f299ca5a6a887d2db6"
}
],
"schema_version": "1.4.0",
"severity": []
}
Sightings
| Author | Source | Type | Date |
|---|
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