CVE-2023-53624

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

State: Published
Severity: Not scored
Published: Oct 7, 2025
Updated: May 11, 2026
Reserved: Oct 7, 2025

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

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	afe4fd062416b158a8a8538b23adc1930a9b88dc to before 4b8a05e3801661a0438fcd0cdef181030d966a5aAffected afe4fd062416b158a8a8538b23adc1930a9b88dc to before d0b43125ec892aeb1b03e5df5aab595097da225aAffected afe4fd062416b158a8a8538b23adc1930a9b88dc to before 4fbefeab88c6e79753a25099d455d3d59d2946b4Affected afe4fd062416b158a8a8538b23adc1930a9b88dc to before 85f24cb2f10b2b0f2882e5786a09b4790bb3a0adAffected afe4fd062416b158a8a8538b23adc1930a9b88dc to before 2322462d6f9ad4874f4e3c63df3b5cc00cb1acbdAffected afe4fd062416b158a8a8538b23adc1930a9b88dc to before 7041101ff6c3073fd8f2e99920f535b111c929cbAffected
LinuxLinux	3.12Affected before 3.12Not affected 5.10.180 through 5.10.Not affected 5.15.111 through 5.15.Not affected 6.1.28 through 6.1.Not affected 6.2.15 through 6.2.Not affected 6.3.2 through 6.3.*Not affected 6.4 and laterNot affected

Product

Versions

LinuxLinux

afe4fd062416b158a8a8538b23adc1930a9b88dc to before 4b8a05e3801661a0438fcd0cdef181030d966a5aAffected
afe4fd062416b158a8a8538b23adc1930a9b88dc to before d0b43125ec892aeb1b03e5df5aab595097da225aAffected
afe4fd062416b158a8a8538b23adc1930a9b88dc to before 4fbefeab88c6e79753a25099d455d3d59d2946b4Affected
afe4fd062416b158a8a8538b23adc1930a9b88dc to before 85f24cb2f10b2b0f2882e5786a09b4790bb3a0adAffected
afe4fd062416b158a8a8538b23adc1930a9b88dc to before 2322462d6f9ad4874f4e3c63df3b5cc00cb1acbdAffected
afe4fd062416b158a8a8538b23adc1930a9b88dc to before 7041101ff6c3073fd8f2e99920f535b111c929cbAffected

LinuxLinux

3.12Affected
before 3.12Not affected
5.10.180 through 5.10.*Not affected
5.15.111 through 5.15.*Not affected
6.1.28 through 6.1.*Not affected
6.2.15 through 6.2.*Not affected
6.3.2 through 6.3.*Not affected
6.4 and laterNot affected

References

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