Bug 2461442 (CVE-2026-31609)

Summary:	CVE-2026-31609 kernel: smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()
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:
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Doc Text:	A flaw was found in the Linux kernel's Server Message Block (SMB) client. This vulnerability, a double-free, occurs in the `smbd_free_send_io()` function after `smbd_send_batch_flush()` has already freed the memory. This memory corruption can lead to a denial of service (DoS) for the affected system.	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 2026-04-24 15:01:44 UTC

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

smb: client: avoid double-free in smbd_free_send_io() after smbd_send_batch_flush()

smbd_send_batch_flush() already calls smbd_free_send_io(),
so we should not call it again after smbd_post_send()
moved it to the batch list.

Comment 1 Keith Grant 2026-04-24 19:42:51 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2026042421-CVE-2026-31609-fc3f@gregkh/T