CVE-2026-72431: alloc_tag: fix use-after-free in /proc/allocinfo after module unload

Q: What is the severity of CVE-2026-72431?

CVE-2026-72431 has been assigned a risk rating of 42, indicating a significant severity level.

Q: How do I fix CVE-2026-72431?

To fix CVE-2026-72431, users should update to the latest version of the Linux kernel that contains the patch addressing this vulnerability.

Q: What systems are affected by CVE-2026-72431?

CVE-2026-72431 affects versions of the Linux kernel that utilize the allocinfo functionality.

Q: What type of vulnerability is CVE-2026-72431?

CVE-2026-72431 is classified as a Use After Free vulnerability.

Q: When was CVE-2026-72431 published?

CVE-2026-72431 was published on August 15, 2026.

Published Aug 15, 2026

Updated

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

alloctag: fix use-after-free in /proc/allocinfo after module unload

allocinfostart() only reinitializes the codetag iterator at position 0. For subsequent reads (position > 0), it reuses cached iterator state from the previous batch. allocinfostop() drops modlock between read batches, which allows module unload to complete and free the module memory that the cached iterator still references:

CPU0 (read) CPU1 (rmmod) ---- ---- allocinfostart(pos=0) downread(modlock) allocinfoshow() ... allocinfostop() upread(modlock) codetagunloadmodule() kfree(cmod) releasemoduletags() ... freemodmem() allocinfostart(pos=N) downread(modlock) // reuses cached iter, skips re-init allocinfoshow() ct->filename <-- UAF

After freemodmem() frees the module's .rodata, allocinfoshow() dereferences ct->filename, ct->function which point there.

Save the iterator state in allocinfonext() and resume from it in allocinfostart() with codetagnextct(), which detects module removal via idrfind() returning NULL and skips to the next module.

Affected Software

130 affected componentsFixes available

Linux Kernel

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-5.11*

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-allwinner-5.19*

ubuntu/linux-aws-5.19*

ubuntu/linux-aws-6.2*

ubuntu/linux-aws-6.5*

ubuntu/linux-azure-5.19*

ubuntu/linux-azure-6.2*

ubuntu/linux-azure-6.5*

ubuntu/linux-azure-fde-5.19*

ubuntu/linux-azure-fde-6.2*

ubuntu/linux-gcp-5.19*

ubuntu/linux-gcp-6.2*

ubuntu/linux-gcp-6.5*

ubuntu/linux-hwe-5.19*

ubuntu/linux-hwe-6.2*

ubuntu/linux-hwe-6.5*

ubuntu/linux-intel-iot-realtime*

ubuntu/linux-lowlatency-hwe-5.19*

ubuntu/linux-lowlatency-hwe-6.2*

ubuntu/linux-lowlatency-hwe-6.5*

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-6.5*

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-aws-6.14*

ubuntu/linux-aws-6.17*

ubuntu/linux-aws-7.0<7.0.0-1014.14~24.04.1

7.0.0-1014.14~24.04.1

ubuntu/linux-azure-6.11*

ubuntu/linux-azure-6.14*

ubuntu/linux-azure-6.17*

ubuntu/linux-azure-7.0<7.0.0-1017.17~24.04.1

7.0.0-1017.17~24.04.1

ubuntu/linux-azure-fde-6.14*

ubuntu/linux-azure-fde-6.17*

ubuntu/linux-azure-fde-7.0<7.0.0-1016.16~24.04.1

7.0.0-1016.16~24.04.1

ubuntu/linux-azure-nvidia-6.14*

ubuntu/linux-gcp-6.11*

ubuntu/linux-gcp-6.14*

ubuntu/linux-gcp-7.0<7.0.0-1014.14~24.04.1

7.0.0-1014.14~24.04.1

ubuntu/linux-hwe-6.11*

ubuntu/linux-hwe-6.14*

ubuntu/linux-hwe-6.17*

ubuntu/linux-hwe-7.0<7.0.0-38.38~24.04.4

7.0.0-38.38~24.04.4

ubuntu/linux-lowlatency-hwe-6.11*

ubuntu/linux-nvidia-6.11*

ubuntu/linux-nvidia-6.17*

ubuntu/linux-nvidia-7.0<7.0.0-1024.25~24.04.1

7.0.0-1024.25~24.04.1

ubuntu/linux-oem-6.11*

ubuntu/linux-oem-6.14*

ubuntu/linux-oem-6.17*

ubuntu/linux-oem-6.8*

ubuntu/linux-oracle-6.14*

ubuntu/linux-oracle-6.17*

ubuntu/linux-oracle-7.0<7.0.0-1013.13~24.04.1

7.0.0-1013.13~24.04.1

ubuntu/linux-raspi-realtime*

ubuntu/linux-realtime*

ubuntu/linux-riscv*

ubuntu/linux-riscv-6.14*

ubuntu/linux-riscv-6.17*

ubuntu/linux-riscv-7.0<7.0.0-38.38.1~24.04.1

7.0.0-38.38.1~24.04.1

ubuntu/linux-realtime-6.14*

ubuntu/linux-realtime-6.17*

ubuntu/linux<7.0.0-38.38

7.0.0-38.38

ubuntu/linux-aws<7.0.0-1014.14

7.0.0-1014.14

ubuntu/linux-azure<7.0.0-1017.17

7.0.0-1017.17

ubuntu/linux-azure-fde<7.0.0-1016.16

7.0.0-1016.16

ubuntu/linux-gcp<7.0.0-1014.14

7.0.0-1014.14

ubuntu/linux-gke<7.0.0-1008.9

7.0.0-1008.9

ubuntu/linux-ibm<7.0.0-1015.15

7.0.0-1015.15

ubuntu/linux-nvidia*

ubuntu/linux-nvidia-bos<7.0.0-2022.23

7.0.0-2022.23

ubuntu/linux-oem-7.0<7.0.0-1015.15

7.0.0-1015.15

ubuntu/linux-oracle<7.0.0-1013.13

7.0.0-1013.13

ubuntu/linux-raspi*

ubuntu/linux-realtime<7.0.0-38.38.1

7.0.0-38.38.1

ubuntu/linux-riscv<7.0.0-38.38.1

7.0.0-38.38.1

ubuntu/linux-vmware*

Remediation

Recommended actions to resolve this vulnerability, in priority order.

Upgrade
Upgrade ubuntu/linux-aws-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1017.17~24.04.1
Upgrade
Upgrade ubuntu/linux-azure-fde-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1016.16~24.04.1
Upgrade
Upgrade ubuntu/linux-gcp-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14~24.04.1
Upgrade
Upgrade ubuntu/linux-hwe-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38~24.04.4
Upgrade
Upgrade ubuntu/linux-nvidia-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1024.25~24.04.1
Upgrade
Upgrade ubuntu/linux-oracle-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13~24.04.1
Upgrade
Upgrade ubuntu/linux-riscv-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38.1~24.04.1
Upgrade
Upgrade ubuntu/linux to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38
Upgrade
Upgrade ubuntu/linux-aws to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14
Upgrade
Upgrade ubuntu/linux-azure to a version that resolves this vulnerability.
Fixed in 7.0.0-1017.17
Upgrade
Upgrade ubuntu/linux-azure-fde to a version that resolves this vulnerability.
Fixed in 7.0.0-1016.16
Upgrade
Upgrade ubuntu/linux-gcp to a version that resolves this vulnerability.
Fixed in 7.0.0-1014.14
Upgrade
Upgrade ubuntu/linux-gke to a version that resolves this vulnerability.
Fixed in 7.0.0-1008.9
Upgrade
Upgrade ubuntu/linux-ibm to a version that resolves this vulnerability.
Fixed in 7.0.0-1015.15
Upgrade
Upgrade ubuntu/linux-nvidia-bos to a version that resolves this vulnerability.
Fixed in 7.0.0-2022.23
Upgrade
Upgrade ubuntu/linux-oem-7.0 to a version that resolves this vulnerability.
Fixed in 7.0.0-1015.15
Upgrade
Upgrade ubuntu/linux-oracle to a version that resolves this vulnerability.
Fixed in 7.0.0-1013.13
Upgrade
Upgrade ubuntu/linux-realtime to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38.1
Upgrade
Upgrade ubuntu/linux-riscv to a version that resolves this vulnerability.
Fixed in 7.0.0-38.38.1

Event History

Aug 15, 2026

CVE Published

via MITRE·05:56 AM

Data Sourced

via MITRE·05:56 AM

Description

Data Sourced

via OSV·06:22 AM

DescriptionSeverityAffected Software

Data Sourced

via NVD·06:22 AM

Description

Frequently Asked Questions

What is the severity of CVE-2026-72431?

CVE-2026-72431 has been assigned a risk rating of 42, indicating a significant severity level.

How do I fix CVE-2026-72431?

To fix CVE-2026-72431, users should update to the latest version of the Linux kernel that contains the patch addressing this vulnerability.

What systems are affected by CVE-2026-72431?

CVE-2026-72431 affects versions of the Linux kernel that utilize the allocinfo functionality.

What type of vulnerability is CVE-2026-72431?

CVE-2026-72431 is classified as a Use After Free vulnerability.

When was CVE-2026-72431 published?

CVE-2026-72431 was published on August 15, 2026.

CVE-2026-72431: alloc_tag: fix use-after-free in /proc/allocinfo after module unload

Affected Software

Remediation

Event History

Frequently Asked Questions

What is the severity of CVE-2026-72431?

How do I fix CVE-2026-72431?

What systems are affected by CVE-2026-72431?

What type of vulnerability is CVE-2026-72431?

When was CVE-2026-72431 published?

Company

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