CVE-2023-53624 — net/sched: sch_fq: fix integer overflow of "credit"
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 v…
Published: 2025-10-07 · CVSS: Unscored
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
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7