CVE-2025-39825

smb: client: fix race with concurrent opens in rename(2)

MEDIUM
4.7
CVSS Score
Published: September 16, 2025 at 01:00 PM UTC
Updated: October 19, 2026 at 09:10 PM UTC
3 products affected across 3 vendorsLinux KernelDebian LinuxSIMATIC CN 4100

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Severity
MEDIUM4.7
Exploit prediction
EPSS 0.1%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix race with concurrent opens in rename(2) Besides sending the rename request to the server, the rename process also involves closing any deferred close, waiting for outstanding I/O to complete as well as marking all existing open handles as deleted to prevent them from deferring closes, which increases the race window for potential concurrent opens on the target file. Fix this by unhashing the dentry in advance to prevent any concurrent opens on the target.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

5.13 ≤ v < 6.1.1506.13 ≤ v < 6.16.56.2 ≤ v < 6.6.1046.7 ≤ v < 6.12.456.176.17 rc178c09634f7dc061a3bd09704cdbebb3762a45cdf
Vendor states this is fixed in 24b9ed739c8c5b464d983e12cf308982f3ae93c2 (fixed)
Vendor states this is fixed in 289f945acb20b9b54fe4d13895e44aa58965ddb2 (fixed)
Vendor states this is fixed in c9991af5e09924f6f3b3e6996a5e09f9504b4358 (fixed)
Vendor states this is fixed in c9e7de284da0be5b44dbe79d71573f9f7f9b144c (fixed)
Vendor states this is fixed in d84291fc7453df7881a970716f8256273aca5747 (fixed)
Vendor states this is fixed in 5.13 (unaffected)
Vendor states this is fixed in 6.1.150 (unaffected)
Vendor states this is fixed in 6.12.45 (unaffected)
Vendor states this is fixed in 6.16.5 (unaffected)
Vendor states this is fixed in 6.17 (unaffected)
Vendor states this is fixed in 6.6.104 (unaffected)
v < V5.0
Affected range stops below V5.0, so it looks safe — our inference, not a vendor statement

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/24b9ed739c8c5b464d983e12cf308982f3ae93c2
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/289f945acb20b9b54fe4d13895e44aa58965ddb2
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c9991af5e09924f6f3b3e6996a5e09f9504b4358
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/c9e7de284da0be5b44dbe79d71573f9f7f9b144c
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/d84291fc7453df7881a970716f8256273aca5747
Mailing ListThird Party Advisory
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Source: 0b142b55-0307-4c5a-b3c9-f314f3fb7c5e
https://cert-portal.siemens.com/productcert/html/ssa-032379.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

Attack Vector
LOCAL
Complexity
HIGH
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-362

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