Bug 2541181 (CVE-2026-97954)

Summary:	CVE-2026-97954 kernel: net/rds: fix tcp stream corruption with large pages
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 Reliable Datagram Sockets (RDS) subsystem. This vulnerability allows a network user to cause a Denial of Service (DoS) by corrupting TCP communication streams. On systems configured with memory page sizes larger than 8 KB, the kernel incorrectly calculates buffer lengths when mapping memory pages for RDS congestion maps. Consequently, extraneous bytes are transmitted across the network connection and misread as message headers, corrupting the stream and causing connections to hang.	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 2026-09-25 10:55:27 UTC

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

net/rds: fix tcp stream corruption with large pages

rds_message_map_pages() assigns PAGE_SIZE bytes to every
scatterlist entry, even when total_len ends in a partial page. The RDS
congestion map is defined as 8192 bytes, so on systems with PAGE_SIZE
greater than 8192 the scatterlist maps bytes beyond the end of the
congestion map.  RDS-TCP transmits the SG contents according to those
lengths, so the extra bytes become part of the TCP RDS stream and are
interpreted as subsequent RDS message headers, corrupting the stream.

Limit the final scatterlist mapping to the number of bytes remaining.
This has no effect on systems with a 4K page size and allows RDS-TCP to
be used on systems with 16K and larger page sizes.

The RDS selftest, which previously hung on 16K pages, now passes.

Comment 1 gkamathe 2026-09-30 02:25:29 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97954.mbox