s390/vfio-ap: Fix NULL deref in status_show() during queue probe
In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: Fix NULL deref in status_show() during queue probe When vfio_ap_mdev_probe_queue() creates the sysfs attribute group, the queue's driver data has not yet been set. A concurrent read of the 'status' attribute can therefore call dev_get_drvdata() and get NULL, which is then passed directly to vfio_ap_mdev_for_queue() where q->apqn is unconditionally dereferenced, causing a NULL pointer dereference. Fix this by acquiring the update locks before calling sysfs_create_group(). The status_show() function acquires guests_lock before reading the driver data, so any concurrent read will block until after dev_set_drvdata() has been called and the update locks are released. As a bonus, the APQN no longer needs to be read from the queue struct after allocation — it can be read directly from apdev before allocation and stored in a local variable, which is then assigned to q->apqn once the allocation succeeds.
CVE-2026-89955
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89955
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "260f3ea141382386e97611e7c2029bc013088ab1",
"lessThan": "31fa0a8a3c337ed2d200166d6926ab23c14f8b2e",
"versionType": "git"
},
{
"status": "affected",
"version": "260f3ea141382386e97611e7c2029bc013088ab1",
"lessThan": "e102ce0f4af99dff769a4b1b4daa4cc6bd5ad2d9",
"versionType": "git"
},
{
"status": "affected",
"version": "260f3ea141382386e97611e7c2029bc013088ab1",
"lessThan": "69632952aca04caa71e49953b6949fc04e788e67",
"versionType": "git"
},
{
"status": "affected",
"version": "260f3ea141382386e97611e7c2029bc013088ab1",
"lessThan": "7db2511fc601ca3a6e3fb1bdce02261c3c3167c3",
"versionType": "git"
},
{
"status": "affected",
"version": "260f3ea141382386e97611e7c2029bc013088ab1",
"lessThan": "dd6f4ef6f8a37412909ad787c837332fb070159c",
"versionType": "git"
}
],
"programFiles": [
"drivers/s390/crypto/vfio_ap_ops.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.0"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.0",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.5",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/s390/crypto/vfio_ap_ops.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89955
Source reference:
/cveMetadata/cveId
Publisher severity
No explicit severity was provided.
- Event
- #36396 · Revision 1
- Added to Heist Feed
- Publisher date