Bug 2468062 (CVE-2026-43304)

Summary:	CVE-2026-43304 kernel: libceph: define and enforce CEPH_MAX_KEY_LEN
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:	rhel-process-autobot, 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 `libceph` component of the Linux kernel. This vulnerability occurs when the kernel processes authentication keys, specifically in the `process_auth_done()` function, where it fails to properly enforce a maximum length for key material. An attacker could exploit this by providing an overly long key, potentially leading to a buffer overflow. This could result in a denial of service (DoS) or other unpredictable system behavior.	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 2026-05-08 14:02:34 UTC

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

libceph: define and enforce CEPH_MAX_KEY_LEN

When decoding the key, verify that the key material would fit into
a fixed-size buffer in process_auth_done() and generally has a sane
length.

The new CEPH_MAX_KEY_LEN check replaces the existing check for a key
with no key material which is a) not universal since CEPH_CRYPTO_NONE
has to be excluded and b) doesn't provide much value since a smaller
than needed key is just as invalid as no key -- this has to be handled
elsewhere anyway.

Comment 1 Keith Grant 2026-05-08 18:40:56 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026050857-CVE-2026-43304-a225@gregkh/T