CVE-2025-38000

Advisory lineage Upstream: 0 Downstream: 147
Analyzed
Published: 06 Jun 2025, 13:03
Last modified:11 May 2026, 21:19

Vulnerability Summary

Overall Risk (default)
medium
31/100
CVSS Score
7.8 HIGH
v3.1 (nvd)
EPSS Score
0.08% LOW
0% probability +0.06%
KEV
Not listed
Ransomware
No reports
Public exploits
None found
Dark Web
Not detected

Timeline

06 Jun 2025, 13:03
Published
Vulnerability first disclosed
11 May 2026, 21:19
Last Modified
Vulnerability information updated

Description

In the Linux kernel, the following vulnerability has been resolved: sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue() When enqueuing the first packet to an HFSC class, hfsc_enqueue() calls the child qdisc's peek() operation before incrementing sch->q.qlen and sch->qstats.backlog. If the child qdisc uses qdisc_peek_dequeued(), this may trigger an immediate dequeue and potential packet drop. In such cases, qdisc_tree_reduce_backlog() is called, but the HFSC qdisc's qlen and backlog have not yet been updated, leading to inconsistent queue accounting. This can leave an empty HFSC class in the active list, causing further consequences like use-after-free. This patch fixes the bug by moving the increment of sch->q.qlen and sch->qstats.backlog before the call to the child qdisc's peek() operation. This ensures that queue length and backlog are always accurate when packet drops or dequeues are triggered during the peek.

CVSS Metrics

  • v3.1•HIGH•Score: 7.8CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS Trends

Current EPSS score: 0.08%• Percentile: 24%

Techniques & Countermeasures

  • CWE-416•Use After Free

    The product reuses or references memory after it has been freed. At some point afterward, the memory may be allocated again and saved in another pointer, while the original pointer references a location somewhere within the new allocation. Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

Affected Systems

  • debian•debian_linux

    11.0

  • linux•linux

    ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 1034e3310752e8675e313f7271b348914008719a | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < f9f593e34d2fb67644372c8f7b033bdc622ad228 | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 89c301e929a0db14ebd94b4d97764ce1d6981653 | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < f1dde3eb17dc1b8bd07aed00004b1e05fc87a3d4 | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 93c276942e75de0e5bc91576300d292e968f5a02 | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 49b21795b8e5654a7df3d910a12e1060da4c04cf | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 3f3a22eebbc32b4fa8ce9c1d5f9db214b45b9335 | ≥ 12d0ad3be9c3854e52ec74bb83bb6f43612827c7, < 3f981138109f63232a5fb7165938d4c945cc1b9d | 4.8

  • linux•linux_kernel

    ≥ 4.8, < 5.4.294 | ≥ 5.5, < 5.10.238 | ≥ 5.11, < 5.15.185 | ≥ 5.16, < 6.1.141 | ≥ 6.2, < 6.6.93 | ≥ 6.7, < 6.12.31 | ≥ 6.13, < 6.14.9 | 6.15:rc1 | 6.15:rc2 | 6.15:rc3 | 6.15:rc4 | 6.15:rc5 | 6.15:rc6 | 6.15:rc7

References (10)