Bug 2559651 (CVE-2026-98917)

Summary:	CVE-2026-98917 kernel: parisc: Increase kernel stack size to 32kb
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	---
Doc Text:	A flaw was found in the Linux kernel's PA-RISC architecture support. This vulnerability can lead to a Denial of Service (DoS) when deep call chains cause a kernel stack overflow on 64-bit systems. A local user executing complex or resource-intensive workloads can trigger this condition, causing the system to crash.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-10-23 12:52:08 UTC

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

Comment 1 Mauro Matteo Cascella 2026-10-27 10:32:53 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98917.mbox