---
id: "CVE-2026-98917"
kind: "vulnerability"
aliases: ["CVE-2026-98917"]
title: "Linux parisc kernel: stack too small, crashes under heavy builds"
severity: "unknown"
cvss: null
epss: 0.00206
exploited: false
status: "open"
category: "infrastructure"
products: []
ecosystems: []
tags: ["infrastructure", "kernel", "linux", "parisc"]
not_affected_if: ["non-parisc-architecture"]
published_at: "2026-10-23T13:17:12+00:00"
first_seen_at: "2026-10-23T21:57:33+00:00"
updated_at: "2026-10-25T12:38:50+00:00"
sources: [{"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-98917", "first_seen_at": "2026-10-23T21:57:33+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-98917", "first_seen_at": "2026-10-25T12:38:50+00:00"}]
---

# Linux parisc kernel: stack too small, crashes under heavy builds

On 64-bit parisc Linux kernels the default kernel stack was too small, so deep call chains could overflow it and panic the machine. The fix raises the kernel stack size to 32 kB.

_Summary, check and fix written by a model from the sources; labelled as such._

## How to check

- `unknown`

## Fix

- Move to a Linux kernel release that includes the parisc change raising THREAD_SIZE_ORDER to 32 kB (version unknown from the sources).

## Timeline

- 2026-10-23T21:57:33+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-98917
- 2026-10-25T12:38:50+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-98917

## From the sources

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

parisc: Increase kernel stack size to 32kb

For 64-bit Linux kernels, increase the default kernel stack size
(THREAD_SIZE_ORDER) to 32 kB, in order to avoid kernel crashes which have been
triggered recently when building the debian vtk9 package with gcc 17:

stackcheck: kworker/u128:0 will most likely overflow kernel stack (sp:179a83af0, stk bottom-top:179a80000-179a84000)
Kernel panic - not syncing: low stack detected by irq handler - check messages
CPU: 2 UID: 0 PID: 30760 Comm: kworker/u128:0 Tainted: G W 6.18.46-dirty #1 NONE
Tainted: [W]=WARN
Hardware name: 9000/800/rp3440
Workqueue: writeback wb_workfn (flush-259:0)
Backtrace:
 [<000000004022f050>] show_stack+0x70/0x90
 [<000000004022378c>] dump_stack_lvl+0x124/0x190
 [<000000004022382c>] dump_stack+0x34/0x48
 [<000000004020212c>] vpanic+0x204/0x648
 [<00000000402025c4>] panic+0x54/0x58
 [<0000000040232230>] do_cpu_irq_mask+0x3f8/0x440
 [<0000000040227070>] intr_return+0x0/0xc

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_