Bug 2511932 (CVE-2026-64597)

Summary:	CVE-2026-64597 kernel: smb: client: fix double-free in SMB2_close() replay
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security <prodsec-ir-bot>
Status:	NEW ---	QA Contact:
Severity:	high	Docs Contact:
Priority:	high
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 Server Message Block (SMB) client. A vulnerability exists in the SMB2_close() replay mechanism where a response buffer can be freed twice. This double-free condition can lead to memory corruption, potentially resulting in a denial of service or the execution of arbitrary code.	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 2026-08-06 07:31:28 UTC

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

smb: client: fix double-free in SMB2_close() replay

A response-bearing attempt can return a replayable error and free its
response buffer. If SMB2_close_init() fails before the next send, cleanup
retains the previous buffer type and frees that response again.

Reset response bookkeeping before each attempt to prevent the stale free.

Comment 1 gkamathe 2026-08-07 06:42:33 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026080652-CVE-2026-64597-760b@gregkh/T