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Vulnerability · Published Oct 7, 2025 · Assigned by Linux

CVE-2023-53624net/sched: sch_fq: fix integer overflow of "credit"

Medium 5.5

In plain English

A medium-severity security flaw in Linux from Linux. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 11% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS NVD)5.5Medium
Exploit odds (30 days)0.2%top 89.0% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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 packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12linux6.1.37-1DEBIAN-CVE-2023-53624
Debian:13linux6.3.7-1DEBIAN-CVE-2023-53624
Debian:14linux6.3.7-1DEBIAN-CVE-2023-53624
Ubuntu:22.04:LTSlinux5.15.0-79.86UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-allwinner-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-aws5.15.0-1042.47UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-aws-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-aws-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-aws-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure5.15.0-1045.52UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-azure-6.11no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-fde5.15.0-1045.52.1UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-fde-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-azure-fde-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gcp5.15.0-1039.47UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gcp-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-gcp-6.11no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gcp-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gcp-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gke5.15.0-1039.44UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-gkeop5.15.0-1025.30UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-hwe-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-hwe-6.11no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-hwe-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-hwe-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-ibm5.15.0-1035.38UBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-intelno fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-intel-iot-realtimeno fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-intel-iotg5.15.0-1037.42UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-kvm5.15.0-1039.44UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-lowlatency5.15.0-79.88UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-lowlatency-hwe-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-lowlatency-hwe-6.11no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-lowlatency-hwe-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-nvidia5.15.0-1030.30UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-nvidia-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-nvidia-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-nvidia-tegra5.15.0-1016.16UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-nvidia-tegra-igx5.15.0-1002.2UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oem-5.17no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oem-6.0no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oem-6.1no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-oem-6.11no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oem-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-oem-6.8no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oracle5.15.0-1040.46UBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-oracle-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-raspi5.15.0-1035.38UBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-raspi-realtimeno fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-realtimeno fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53624
Ubuntu:24.04:LTSlinux-riscvno fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-riscv-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-riscv-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-starfive-5.19no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-starfive-6.2no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-starfive-6.5no fix listedUBUNTU-CVE-2023-53624
Ubuntu:22.04:LTSlinux-xilinx-zynqmp5.15.0-1025.29UBUNTU-CVE-2023-53624

Affected products (as reported)

VendorProductVersions
Linux Linux afe4fd062416b158a8a8538b23adc1930a9b88dc – before 4b8a05e3801661a0438fcd0cdef181030d966a5aafe4fd062416b158a8a8538b23adc1930a9b88dc – before d0b43125ec892aeb1b03e5df5aab595097da225aafe4fd062416b158a8a8538b23adc1930a9b88dc – before 4fbefeab88c6e79753a25099d455d3d59d2946b4afe4fd062416b158a8a8538b23adc1930a9b88dc – before 85f24cb2f10b2b0f2882e5786a09b4790bb3a0adafe4fd062416b158a8a8538b23adc1930a9b88dc – before 2322462d6f9ad4874f4e3c63df3b5cc00cb1acbdafe4fd062416b158a8a8538b23adc1930a9b88dc – before 7041101ff6c3073fd8f2e99920f535b111c929cb
Linux Linux 3.12

References