Bug 2401421 (CVE-2025-39942)

Summary:	CVE-2025-39942 kernel: Linux kernel (ksmbd): Remote denial of service in smbdirect
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:	rhel-process-autobot, watson-tool-maintainers
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in the Linux kernel's ksmbd component, specifically within the `smbdirect` module. This vulnerability occurs due to insufficient validation of the `remaining_data_length` against the `max_fragmented_recv_size`. A remote attacker could exploit this issue by sending a malformed network packet, which could lead to a denial of service (DoS) condition, making the system unresponsive.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:

Description OSIDB Bzimport 2025-10-04 08:02:19 UTC

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

ksmbd: smbdirect: verify remaining_data_length respects max_fragmented_recv_size

This is inspired by the check for data_offset + data_length.

Comment 1 Alexander B 2025-12-23 14:55:43 UTC

Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025100419-CVE-2025-39942-0297@gregkh/T