CVE-2022-50307: s390/cio: fix out-of-bounds access on cio_ignore free

Published Sep 15, 2025

Updated

In the Linux kernel, the following vulnerability has been resolved:

s390/cio: fix out-of-bounds access on cioignore free

The channel-subsystem-driver scans for newly available devices whenever device-IDs are removed from the cioignore list using a command such as:

echo free >/proc/cioignore

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 iosubchannelprivate. For devices that are bound to a non-default I/O subchannel driver, such as the vfioccw 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 Software

127 affected componentsFixes available

Linux Kernel

Linux Linux kernel>=5.15.1<5.15.78

Linux Linux kernel>=5.16<6.0.7

Linux Linux kernel=5.15

Linux Linux kernel=5.15-rc4

Linux Linux kernel=5.15-rc5

Linux Linux kernel=5.15-rc6

Linux Linux kernel=5.15-rc7

Linux Linux kernel=6.1-rc1

Linux Linux kernel=6.1-rc2

debian/linux<6.0.7-1

6.0.7-1

debian/linux<6.0.7-1

6.0.7-1

debian/linux<6.0.7-1

6.0.7-1

linux/kernel>=5.15.0<5.15.78

5.15.78

linux/kernel>=5.16.0<6.0.7

6.0.7

debian/linux

6.1.176-16.1.190-16.12.107-16.12.115-27.2.15-1

ubuntu/linux-hwe-edge*

ubuntu/linux-aws-5.0*

ubuntu/linux-aws-5.3*

ubuntu/linux-azure*

ubuntu/linux-azure-5.3*

ubuntu/linux-azure-edge*

ubuntu/linux-gcp*

ubuntu/linux-gcp-5.3*

ubuntu/linux-gke-4.15*

ubuntu/linux-gke-5.4*

ubuntu/linux-gkeop-5.4*

ubuntu/linux-hwe*

ubuntu/linux-hwe-edge*

ubuntu/linux-oem*

ubuntu/linux-oracle-5.0*

ubuntu/linux-oracle-5.3*

ubuntu/linux-aws-5.15<5.15.0-1030.34~20.04.1

5.15.0-1030.34~20.04.1

ubuntu/linux-azure-5.15<5.15.0-1033.40~20.04.1

5.15.0-1033.40~20.04.1

ubuntu/linux-gcp-5.15<5.15.0-1029.36~20.04.1

5.15.0-1029.36~20.04.1

ubuntu/linux-hwe-5.15<5.15.0-60.66~20.04.1

5.15.0-60.66~20.04.1

ubuntu/linux-intel-iotg-5.15<5.15.0-1025.30~20.04.1

5.15.0-1025.30~20.04.1

ubuntu/linux-lowlatency-hwe-5.15<5.15.0-60.66~20.04.1

5.15.0-60.66~20.04.1

ubuntu/linux-oracle-5.15<5.15.0-1029.35~20.04.1

5.15.0-1029.35~20.04.1

ubuntu/linux-riscv-5.15<5.15.0-1029.33~20.04.1

5.15.0-1029.33~20.04.1

ubuntu/linux-aws-5.11*

ubuntu/linux-aws-5.13*

ubuntu/linux-aws-5.8*

ubuntu/linux-azure-5.11*

ubuntu/linux-azure-5.13*

ubuntu/linux-azure-5.8*

ubuntu/linux-azure-fde*

ubuntu/linux-gcp-5.11*

ubuntu/linux-gcp-5.13*

ubuntu/linux-gcp-5.8*

ubuntu/linux-gke*

ubuntu/linux-gke-5.15*

ubuntu/linux-gkeop*

ubuntu/linux-gkeop-5.15*

ubuntu/linux-hwe-5.11*

ubuntu/linux-hwe-5.13*

ubuntu/linux-hwe-5.8*

ubuntu/linux-intel-5.13*

ubuntu/linux-oem-5.10*

ubuntu/linux-oem-5.13*

ubuntu/linux-oem-5.6*

ubuntu/linux-oracle-5.11*

ubuntu/linux-oracle-5.13*

ubuntu/linux-oracle-5.8*

ubuntu/linux-raspi2*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.11*

ubuntu/linux-riscv-5.8*

ubuntu/linux<5.15.0-60.66

5.15.0-60.66

ubuntu/linux-allwinner-5.19*

ubuntu/linux-aws<5.15.0-1030.34

5.15.0-1030.34

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-azure<5.15.0-1033.40

5.15.0-1033.40

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-fde<5.15.0-1033.40.1

5.15.0-1033.40.1

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp<5.15.0-1029.36

5.15.0-1029.36

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-gke<5.15.0-1027.32

5.15.0-1027.32

ubuntu/linux-gkeop<5.15.0-1015.19

5.15.0-1015.19

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-ibm<5.15.0-1025.28

5.15.0-1025.28

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-intel-iotg<5.15.0-1025.30

5.15.0-1025.30

ubuntu/linux-kvm<5.15.0-1028.33

5.15.0-1028.33

ubuntu/linux-lowlatency<5.15.0-60.66

5.15.0-60.66

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

ubuntu/linux-nvidia<5.15.0-1017.17

5.15.0-1017.17

ubuntu/linux-nvidia-6.2*

ubuntu/linux-nvidia-6.5*

ubuntu/linux-oem-5.17*

ubuntu/linux-oem-6.0*

ubuntu/linux-oem-6.1*

ubuntu/linux-oem-6.5*

ubuntu/linux-oracle<5.15.0-1029.35

5.15.0-1029.35

ubuntu/linux-oracle-6.5*

ubuntu/linux-raspi<5.15.0-1024.26

5.15.0-1024.26

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-5.19*

ubuntu/linux-riscv-6.5*

ubuntu/linux-starfive-5.19*

ubuntu/linux-starfive-6.2*

ubuntu/linux-starfive-6.5*

ubuntu/linux-bluefield<5.15.0-1014.16

5.15.0-1014.16

ubuntu/linux-azure-6.11*

ubuntu/linux-gcp-6.11*

ubuntu/linux-hwe-6.11*

ubuntu/linux-intel*

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.8*

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.0.7-1
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 5.15.78
Upgrade
Upgrade linux/Kernel to a version that resolves this vulnerability.
Fixed in 6.0.7
Upgrade
Upgrade debian/linux to a version that resolves this vulnerability.
Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.115-2Fixed in 7.2.15-1
Upgrade
Upgrade ubuntu/linux-aws-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1030.34~20.04.1
Upgrade
Upgrade ubuntu/linux-azure-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.40~20.04.1
Upgrade
Upgrade ubuntu/linux-gcp-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1029.36~20.04.1
Upgrade
Upgrade ubuntu/linux-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-60.66~20.04.1
Upgrade
Upgrade ubuntu/linux-intel-iotg-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1025.30~20.04.1
Upgrade
Upgrade ubuntu/linux-lowlatency-hwe-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-60.66~20.04.1
Upgrade
Upgrade ubuntu/linux-oracle-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1029.35~20.04.1
Upgrade
Upgrade ubuntu/linux-riscv-5.15 to a version that resolves this vulnerability.
Fixed in 5.15.0-1029.33~20.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 5.15.0-60.66
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 5.15.0-1030.34
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.40
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 5.15.0-1033.40.1
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 5.15.0-1029.36
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 5.15.0-1027.32
Upgrade
Upgrade ubuntu/linux-gkeop to a version that resolves this vulnerability.
Fixed in 5.15.0-1015.19
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 5.15.0-1025.28
Upgrade
Upgrade ubuntu/linux-intel-iotg to a version that resolves this vulnerability.
Fixed in 5.15.0-1025.30
Upgrade
Upgrade ubuntu/linux-kvm to a version that resolves this vulnerability.
Fixed in 5.15.0-1028.33
Upgrade
Upgrade ubuntu/linux-lowlatency to a version that resolves this vulnerability.
Fixed in 5.15.0-60.66
Upgrade
Upgrade ubuntu/linux-nvidia to a version that resolves this vulnerability.
Fixed in 5.15.0-1017.17
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 5.15.0-1029.35
Upgrade
Upgrade ubuntu/linux-raspi to a version that resolves this vulnerability.
Fixed in 5.15.0-1024.26
Upgrade
Upgrade ubuntu/linux-bluefield to a version that resolves this vulnerability.
Fixed in 5.15.0-1014.16
Configuration
Change the scan logic to use the driver-independent struct subchannel->config.ena indication of the driver's requested subchannel-enabled state, rather than assuming that an I/O subchannel's drvdata points to struct io_subchannel_private.
Linux kernel s390/cio channel-subsystem-driver device scan online indication = struct subchannel->config.ena

Event History

Sep 15, 2025

CVE Published

via MITRE·02:46 PM

Data Sourced

via MITRE·02:46 PM

Description

Data Sourced

via OSV·02:46 PM

DescriptionAffected Software

Data Sourced

via NVD·03:15 PM

RemedyDescriptionSeverityWeaknessAffected Software

Nov 11, 2026

Data Sourced

via OSV·09:37 AM

Severity

Frequently Asked Questions

What is the severity of CVE-2022-50307?

CVE-2022-50307 is classified as a low severity vulnerability.

How does CVE-2022-50307 affect the Linux Kernel?

CVE-2022-50307 allows for out-of-bounds access on the cio_ignore free, potentially leading to unexpected behavior.

How do I fix CVE-2022-50307?

To fix CVE-2022-50307, update your Linux Kernel to the latest stable version where the vulnerability has been patched.

Which versions of the Linux Kernel are affected by CVE-2022-50307?

CVE-2022-50307 affects several versions of the Linux Kernel prior to the release that contains the fix.

What systems are at risk due to CVE-2022-50307?

Systems running vulnerable versions of the Linux Kernel, particularly those using the s390 hardware architecture, are at risk from CVE-2022-50307.

CVE-2022-50307: s390/cio: fix out-of-bounds access on cio_ignore free

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2022-50307?

How does CVE-2022-50307 affect the Linux Kernel?

How do I fix CVE-2022-50307?

Which versions of the Linux Kernel are affected by CVE-2022-50307?

What systems are at risk due to CVE-2022-50307?

Company

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