CVE-2025-38193

net_sched: sch_sfq: reject invalid perturb period

State: Published
Severity: 7.8 High
Published: Jul 4, 2025
Updated: Oct 15, 2026
Reserved: Apr 16, 2025

Description

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

Scores

CVSS	Score	Vector	Source
3.1	7.8 High	CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H	Linux

Weaknesses

The record names no weakness.

Affected Products

Product	Versions
LinuxLinux	1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before e0936ff56be4e08ad5b60ec26971eae0c40af305Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2254d038dab9c194fe6a4b1ce31034f42e91a6e5Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 956b5aebb349449b38d920d444ca1392d43719d1Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b11a50544af691b787384089b68f740ae20a441bAffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 0357da9149eac621f39e235a135ebf155f01f7c3Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f9b97d466e6026ccbdda30bb5b71965b67ccbc82Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 590b2d7d0beadba2aa576708a05a05f0aae39295Affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7ca52541c05c832d32b112274f81a985101f9ba8Affected
LinuxLinux	2.6.12Affected before 2.6.12Not affected 5.4.297 through 5.4.Not affected 5.10.240 through 5.10.Not affected 5.15.186 through 5.15.Not affected 6.1.142 through 6.1.Not affected 6.6.95 through 6.6.Not affected 6.12.35 through 6.12.Not affected 6.15.4 through 6.15.*Not affected 6.16 and laterNot affected

Product

Versions

LinuxLinux

1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before e0936ff56be4e08ad5b60ec26971eae0c40af305Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 2254d038dab9c194fe6a4b1ce31034f42e91a6e5Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 956b5aebb349449b38d920d444ca1392d43719d1Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before b11a50544af691b787384089b68f740ae20a441bAffected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 0357da9149eac621f39e235a135ebf155f01f7c3Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before f9b97d466e6026ccbdda30bb5b71965b67ccbc82Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 590b2d7d0beadba2aa576708a05a05f0aae39295Affected
1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 to before 7ca52541c05c832d32b112274f81a985101f9ba8Affected

LinuxLinux

2.6.12Affected
before 2.6.12Not affected
5.4.297 through 5.4.*Not affected
5.10.240 through 5.10.*Not affected
5.15.186 through 5.15.*Not affected
6.1.142 through 6.1.*Not affected
6.6.95 through 6.6.*Not affected
6.12.35 through 6.12.*Not affected
6.15.4 through 6.15.*Not affected
6.16 and laterNot affected

References

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