CVE-2026-43292

/// Technical description

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

mm/vmalloc: prevent RCU stalls in kasan_release_vmalloc_node

When CONFIG_PAGE_OWNER is enabled, freeing KASAN shadow pages during

vmalloc cleanup triggers expensive stack unwinding that acquires RCU read

locks. Processing a large purge_list without rescheduling can cause the

task to hold CPU for extended periods (10+ seconds), leading to RCU stalls

and potential OOM conditions.

The issue manifests in purge_vmap_node() -> kasan_release_vmalloc_node()

where iterating through hundreds or thousands of vmap_area entries and

freeing their associated shadow pages causes:

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:

rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6229/1:b..l

...

task:kworker/0:17 state:R running task stack:28840 pid:6229

...

kasan_release_vmalloc_node+0x1ba/0xad0 mm/vmalloc.c:2299

purge_vmap_node+0x1ba/0xad0 mm/vmalloc.c:2299

Each call to kasan_release_vmalloc() can free many p

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References