CVE-2023-53624

net/sched: sch_fq: fix integer overflow of "credit"

MEDIUM
5.5
CVSS Score
Published: October 7, 2025 at 03:19 PM UTC
Updated: June 17, 2026 at 06:45 AM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.2%

Description

In the Linux kernel, the following vulnerability has been resolved: net/sched: sch_fq: fix integer overflow of "credit" if sch_fq is configured with "initial quantum" having values greater than INT_MAX, the first assignment of "credit" does signed integer overflow to a very negative value. In this situation, the syzkaller script provided by Cristoph triggers the CPU soft-lockup warning even with few sockets. It's not an infinite loop, but "credit" wasn't probably meant to be minus 2Gb for each new flow. Capping "initial quantum" to INT_MAX proved to fix the issue. v2: validation of "initial quantum" is done in fq_policy, instead of open coding in fq_change() _ suggested by Jakub Kicinski

Affected

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

3.12 ≤ v < 5.10.1803.12 ≤ v < 5.15.1113.12 ≤ v < 6.1.283.12 ≤ v < 6.2.153.12 ≤ v < 6.3.23.12 ≤ v < 6.45.11 ≤ v < 5.15.1115.16 ≤ v < 6.1.286.2 ≤ v < 6.2.156.3 ≤ v < 6.3.23.12afe4fd062416b158a8a8538b23adc1930a9b88dc
Vendor states this is fixed in 2322462d6f9ad4874f4e3c63df3b5cc00cb1acbd (fixed)
Vendor states this is fixed in 4b8a05e3801661a0438fcd0cdef181030d966a5a (fixed)
Vendor states this is fixed in 4fbefeab88c6e79753a25099d455d3d59d2946b4 (fixed)
Vendor states this is fixed in 7041101ff6c3073fd8f2e99920f535b111c929cb (fixed)
Vendor states this is fixed in 85f24cb2f10b2b0f2882e5786a09b4790bb3a0ad (fixed)
Vendor states this is fixed in d0b43125ec892aeb1b03e5df5aab595097da225a (fixed)
Vendor states this is fixed in 3.12 (unaffected)
Vendor states this is fixed in 5.10.180 (unaffected)
Vendor states this is fixed in 5.15.111 (unaffected)
Vendor states this is fixed in 6.1.28 (unaffected)
Vendor states this is fixed in 6.2.15 (unaffected)
Vendor states this is fixed in 6.3.2 (unaffected)
Vendor states this is fixed in 6.4 (unaffected)

CVSS

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

Quick Info

StatusANALYZED
CWE
CWE-190

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