PT-2025-4354 · Linux+6 · Linux Kernel+6

Jay Shin

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Published

2025-01-14

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Updated

2026-05-26

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CVE-2025-21673

CVSS v3.1

5.5

Medium

VectorAV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Linux kernel (affected versions not specified)
Description The issue is related to a double free of TCP Server Info::hostname in the Linux kernel's smb client. When shutting down the server in cifs put tcp session(), the cifsd thread might be reconnecting to multiple DFS targets before it realizes it should exit the loop, so @server->hostname can't be freed as long as the cifsd thread isn't done. This can lead to a denial of service. The reconnect target unlocked() function and reconnect dfs server() function are involved in the issue.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Exploit

Double Free

Weakness Enumeration

Related Identifiers

ALT-PU-2025-12647
ALT-PU-2025-3467
ALT-PU-2025-3500
AZL-56381
AZL-56409
BDU:2025-01467
CVE-2025-21673
ECHO-53BA-199D-720D
OESA-2025-1371
OESA-2025-1372
OPENSUSE-SU-2025_0847-1
OPENSUSE-SU-2025_0856-1
OPENSUSE-SU-2025_0955-1
SUSE-SU-2025:0564-1
SUSE-SU-2025:0834-1
SUSE-SU-2025:0847-1
SUSE-SU-2025:0856-1
SUSE-SU-2025:0955-1
SUSE-SU-2025:20190-1
SUSE-SU-2025:20192-1
SUSE-SU-2025:20260-1
SUSE-SU-2025:20270-1
SUSE-SU-2025_0834-1
SUSE-SU-2025_0847-1
SUSE-SU-2025_0856-1
SUSE-SU-2025_0955-1
USN-7445-1
USN-7448-1
USN-7595-1
USN-7595-2
USN-7595-3
USN-7595-4
USN-7595-5
USN-7596-1
USN-7596-2
USN-7653-1

Affected Products

Alt Linux
Astra Linux
Debian
Linuxmint
Linux Kernel
Suse
Ubuntu