CVE-2026-98224

What it actually does

Incorrect memory accounting occurs when call_mmap_prepare() fails after __mmap_setup() has called security_vm_enough_memory_mm(), leaving vm_acct_memory() increments un-reversed and causing the kernel to retain stale accounting state for the aborted mapping.

Why it matters to the business

Systems may incorrectly enforce memory limits, leading to unexpected process failures or degraded capacity on Linux hosts running affected kernels; low EPSS and absence from KEV indicate limited immediate operational risk but still require patching within normal maintenance windows.

How an attack unfolds

An attacker triggers repeated mmap operations that reach call_mmap_prepare() failure paths, exhausting the kernel's internal accounting counters without actual memory allocation and potentially inducing denial-of-service through artificial memory-limit enforcement.

How to fix it

Update to a Linux kernel containing the corrected __mmap_region() error handling that separates abort paths for __mmap_setup() versus call_mmap_prepare() failures; apply the fix via distribution security updates as soon as available.

How to confirm the fix worked

Confirm the patch is present by inspecting the mm/vma.c source for separate error labels after call_mmap_prepare() and by running kernel regression tests that exercise mmap failure paths under memory-accounting limits.

Typical attack path

1. Identify or craft mmap sequences that cause mmap_prepare() to fail after accounting
2. Trigger the faulty error path repeatedly to accumulate un-reversed vm_acct_memory() state
3. Force the system or container into artificial memory-pressure conditions
4. Observe or exploit resulting process terminations or scheduling anomalies

How to detect it

Review kernel logs for unusual mmap failure patterns combined with memory-accounting warnings; correlate with process coredumps or OOM-killer activity that occurs without corresponding memory growth in /proc.

What your security team should do

• Prioritize kernel updates during the next scheduled maintenance window given low exploit maturity
• Monitor upstream stable and distribution changelogs for the exact commit that separates the abort paths
• Include the corrected kernel in golden images and container base layers before broad deployment