Bug 2536321 (CVE-2026-90219)

Summary:	CVE-2026-90219 kernel: RDMA/cxgb4: Free debugfs on registration failure
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
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 RDMA (Remote Direct Memory Access) cxgb4 module. When an RDMA device registration fails, the debugfs entries, which are used for debugging, are not properly deallocated. This oversight can lead to a resource leak, where these entries persist in memory even after the device is freed. Over time, this accumulation of unreleased resources could potentially lead to a Denial of Service (DoS) due to resource exhaustion.	Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
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Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2026-09-17 17:21:38 UTC

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

RDMA/cxgb4: Free debugfs on registration failure

c4iw_alloc() creates the per-device debugfs tree (dev->debugfs_root via
setup_debugfs()), but it is removed only in c4iw_remove(), not in
c4iw_dealloc().  When RDMA device registration fails, the registration
worker's err_dealloc_ctx path calls c4iw_dealloc() directly, bypassing
c4iw_remove(), so the debugfs dentries leak and outlive the freed
c4iw_dev.

Move debugfs_remove_recursive() into c4iw_dealloc() so every path that
frees ctx->dev also removes its debugfs tree.

Comment 1 Mauro Matteo Cascella 2026-09-24 13:10:18 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-90219.mbox