CVE-2025-21963

cifs: Fix integer overflow while processing acdirmax mount option

MEDIUM
5.5
CVSS Score
Published: April 1, 2025 at 03:46 PM UTC
Updated: June 17, 2026 at 08:44 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

In the Linux kernel, the following vulnerability has been resolved: cifs: Fix integer overflow while processing acdirmax mount option User-provided mount parameter acdirmax of type u32 is intended to have an upper limit, but before it is validated, the value is converted from seconds to jiffies which can lead to an integer overflow. Found by Linux Verification Center (linuxtesting.org) with SVACE.

Affected

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

5.12 ≤ v < 5.15.1805.12 ≤ v < 6.1.1325.12 ≤ v < 6.12.205.12 ≤ v < 6.13.85.12 ≤ v < 6.145.12 ≤ v < 6.6.845.16 ≤ v < 6.1.1326.13 ≤ v < 6.13.86.2 ≤ v < 6.6.846.7 ≤ v < 6.12.204c9f948142a550af416a2bfb5e56d29ce29e92cf6.14 rc16.14 rc26.14 rc36.14 rc46.14 rc56.14 rc6
Vendor states this is fixed in 0c26edf477e093cefc41637f5bccc102e1a77399 (fixed)
Vendor states this is fixed in 2809a79bc64964ce02e0c5f2d6bd39b9d09bdb3c (fixed)
Vendor states this is fixed in 39d086bb3558da9640ef335f97453e01d32578a1 (fixed)
Vendor states this is fixed in 5b29891f91dfb8758baf1e2217bef4b16b2b165b (fixed)
Vendor states this is fixed in 6124cbf73e3dea7591857dd63b8ccece28952afd (fixed)
Vendor states this is fixed in 9e438d0410a4002d24f420f2c28897ba2dc0af64 (fixed)
Vendor states this is fixed in 5.12 (unaffected)
Vendor states this is fixed in 5.15.180 (unaffected)
Vendor states this is fixed in 6.1.132 (unaffected)
Vendor states this is fixed in 6.12.20 (unaffected)
Vendor states this is fixed in 6.13.8 (unaffected)
Vendor states this is fixed in 6.14 (unaffected)
Vendor states this is fixed in 6.6.84 (unaffected)

References (7)

Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/0c26edf477e093cefc41637f5bccc102e1a77399
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/2809a79bc64964ce02e0c5f2d6bd39b9d09bdb3c
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/39d086bb3558da9640ef335f97453e01d32578a1
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/5b29891f91dfb8758baf1e2217bef4b16b2b165b
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/6124cbf73e3dea7591857dd63b8ccece28952afd
Patch
Source: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
https://git.kernel.org/stable/c/9e438d0410a4002d24f420f2c28897ba2dc0af64
Source: af854a3a-2127-422b-91ae-364da2661108
https://lists.debian.org/debian-lts-announce/2025/05/msg00045.html

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

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

CVSS

5.5MEDIUMCISA-ADP
Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusMODIFIED
CWE
CWE-190

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