// For flags

CVE-2025-38193

net_sched: sch_sfq: reject invalid perturb period

Severity Score

7.1
*CVSS v3

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: reject invalid perturb period Gerrard Tai reported that SFQ perturb_period has no range check yet,
and this can be used to trigger a race condition fixed in a separate patch. We want to make sure ctl->perturb_period * HZ will not overflow
and is positive. tc qd add dev lo root sfq perturb -10 # negative value : error
Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 1000000000 # too big : error
Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 2000000 # acceptable value
tc -s -d qd sh dev lo
qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0

In the Linux kernel, the following vulnerability has been resolved: net_sched: sch_sfq: reject invalid perturb period Gerrard Tai reported that SFQ perturb_period has no range check yet, and this can be used to trigger a race condition fixed in a separate patch. We want to make sure ctl->perturb_period * HZ will not overflow and is positive. tc qd add dev lo root sfq perturb -10 # negative value : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 1000000000 # too big : error Error: sch_sfq: invalid perturb period. tc qd add dev lo root sfq perturb 2000000 # acceptable value tc -s -d qd sh dev lo qdisc sfq 8005: root refcnt 2 limit 127p quantum 64Kb depth 127 flows 128 divisor 1024 perturb 2000000sec Sent 0 bytes 0 pkt (dropped 0, overlimits 0 requeues 0) backlog 0b 0p requeues 0

*Credits: N/A
CVSS Scores
Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Attack Vector
Local
Attack Complexity
Medium
Authentication
None
Confidentiality
Complete
Integrity
Complete
Availability
Complete
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2025-04-16 CVE Reserved
  • 2025-07-04 CVE Published
  • 2025-07-28 CVE Updated
  • 2025-08-05 EPSS Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 5.10.240
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 5.10.240"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 5.15.186
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 5.15.186"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.1.142
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.1.142"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.6.95
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.6.95"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.12.35
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.12.35"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.15.4
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.15.4"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 2.6.12 < 6.16
Search vendor "Linux" for product "Linux Kernel" and version " >= 2.6.12 < 6.16"
en
Affected