Bug 2546362 (CVE-2026-98322)

Summary:	CVE-2026-98322 kernel: netfilter: nft_nat: fully initialise new_addr in netmap setup
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 Netfilter network filtering subsystem. When configuring IPv4 Network Address Translation (NAT) rules with the netmap feature, the system fails to initialize a temporary memory buffer on the stack. As a result, uninitialized kernel stack data is copied and processed during packet evaluation. A local user with network administration privileges can exploit this flaw to cause unexpected system behavior, leading to a Denial of Service (DoS) or the potential disclosure of sensitive kernel memory.	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 2026-10-06 09:05:56 UTC

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

netfilter: nft_nat: fully initialise new_addr in netmap setup

nft_nat_setup_netmap() builds the mapped address in an on-stack
union nf_inet_addr. For an IPv4 mapping it writes only the 4-byte .ip
member and the loop runs a single 32-bit iteration, but it then copies
the whole 16-byte union into range->min_addr and range->max_addr, so the
upper 12 bytes reach nf_nat_setup_info() uninitialised.

KMSAN reports an uninit-value in nf_nat_setup_info() reached from
nft_nat_eval(). The IPv6 path fills all 16 bytes and is not affected.

Zero-initialise new_addr.

Comment 1 gkamathe 2026-10-10 06:46:29 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98322.mbox