CVE-2026-80756
Received Received - Intake

SELinux Policy Load NULL Dereference in Linux Kernel

Publication date: 2026-09-03

Last updated on: 2026-09-03

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: selinux: do not cancel a policy conversion that never started sel_write_load() calls selinux_policy_cancel() when sel_make_policy_nodes() fails, and that helper dereferences the outgoing policy to cancel its sidtab conversion. On the first policy load there is no outgoing policy: security_load_policy() returns early for that case, before it converts anything, and state->policy is still NULL. A first load that fails while building the selinuxfs tree therefore takes a NULL dereference in selinux_policy_cancel(), reached from a write(2) to /sys/fs/selinux/load. Skip the cancel when there is no old policy, mirroring the check security_load_policy() already makes before it converts.

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Meta Information

Published
2026-09-03
Last Modified
2026-09-03
Generated
2026-09-03
AI Q&A
2026-09-03
EPSS Evaluated
N/A
NVD
CVE-2026-80756
EUVD
EUVD-2026-70360

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability is in the Linux kernel's SELinux subsystem. It occurs when a policy load fails during the initial setup. The issue arises because the code attempts to cancel a policy conversion that never started. Specifically, sel_write_load() calls selinux_policy_cancel() even when there is no outgoing policy (security_load_policy() returns early for the first load). This leads to a NULL pointer dereference in selinux_policy_cancel().

Detection Guidance

This vulnerability affects the SELinux policy loading mechanism in the Linux kernel. Detection requires checking for kernel logs or errors related to SELinux policy operations, particularly during policy load attempts. Monitor /var/log/messages or dmesg for NULL pointer dereference errors in selinux_policy_cancel() when writing to /sys/fs/selinux/load fails.

Impact Analysis

This vulnerability could cause a system crash or kernel panic if exploited. It affects systems using SELinux with a failing initial policy load. Attackers with local access might trigger this by manipulating policy loading, leading to denial-of-service conditions.

Mitigation Strategies

Apply the latest Linux kernel patches that address this issue. Avoid loading SELinux policies manually until the patch is applied. If SELinux is not critical for your system, consider temporarily disabling it by setting SELINUX=permissive in /etc/selinux/config and rebooting.

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