Bug 2540517 (CVE-2026-97413)

Summary:	CVE-2026-97413 kernel: RDMA/rtrs-srv: Fix integer underflow in process_read and process_write
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 Remote Direct Memory Access (RDMA) subsystem. A malicious client can trigger an integer underflow by sending a specially crafted message with an oversized length field during read or write operations. This improper validation leads to an out-of-bounds memory access, potentially resulting in a system crash (Denial of Service) or memory corruption.	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 2026-09-24 17:05:14 UTC

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

RDMA/rtrs-srv: Fix integer underflow in process_read and process_write

usr_len is read from a network-supplied message field (le16_to_cpu)
and used to compute data_len = off - usr_len without validating that
usr_len <= off. A malicious RDMA client can send usr_len > off causing
an integer underflow, resulting in data_len wrapping to a huge size_t
value which is then passed to the rdma_ev callback as a memory length,
leading to out-of-bounds memory access.

Fix by reading and validating usr_len <= off before rtrs_srv_get_ops_ids()
in both process_read() and process_write(), ensuring the early return
path acquires no reference and has no resource leak.

Comment 1 Mauro Matteo Cascella 2026-09-29 10:14:54 UTC

Upstream advisory:
https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97413.mbox