7.8

CVE-2025-38000

sch_hfsc: Fix qlen accounting bug when using peek in hfsc_enqueue()

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.
Daten sind bereitgestellt durch National Vulnerability Database (NVD)
Linux ≫ Linux Kernel Version >= 4.8 < 5.4.294
Linux ≫ Linux Kernel Version >= 5.5 < 5.10.238
Linux ≫ Linux Kernel Version >= 5.11 < 5.15.185
Linux ≫ Linux Kernel Version >= 5.16 < 6.1.141
Linux ≫ Linux Kernel Version >= 6.2 < 6.6.93
Linux ≫ Linux Kernel Version >= 6.7 < 6.12.31
Linux ≫ Linux Kernel Version >= 6.13 < 6.14.9
Linux ≫ Linux Kernel Version6.15 Updaterc1
Linux ≫ Linux Kernel Version6.15 Updaterc2
Linux ≫ Linux Kernel Version6.15 Updaterc3
Linux ≫ Linux Kernel Version6.15 Updaterc4
Linux ≫ Linux Kernel Version6.15 Updaterc5
Linux ≫ Linux Kernel Version6.15 Updaterc6
Linux ≫ Linux Kernel Version6.15 Updaterc7
Debian ≫ Debian Linux Version11.0
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Zu dieser CVE wurde keine Warnung gefunden.
EPSS Metriken
Typ Quelle Score Percentile
EPSS FIRST.org 0.18% 0.077
CVSS Metriken
Quelle Base Score Exploit Score Impact Score Vector String
nvd@nist.gov 7.8 1.8 5.9
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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 Any operations using the original pointer are no longer valid because the memory "belongs" to the code that operates on the new pointer.

https://git.kernel.org/stable/c/1034e3310752e8675e313f7271b348914008719a
Patch
https://git.kernel.org/stable/c/3f3a22eebbc32b4fa8ce9c1d5f9db214b45b9335
Patch
https://git.kernel.org/stable/c/3f981138109f63232a5fb7165938d4c945cc1b9d
Patch
https://git.kernel.org/stable/c/49b21795b8e5654a7df3d910a12e1060da4c04cf
Patch
https://git.kernel.org/stable/c/89c301e929a0db14ebd94b4d97764ce1d6981653
Patch
https://git.kernel.org/stable/c/93c276942e75de0e5bc91576300d292e968f5a02
Patch
https://git.kernel.org/stable/c/f1dde3eb17dc1b8bd07aed00004b1e05fc87a3d4
Patch
https://git.kernel.org/stable/c/f9f593e34d2fb67644372c8f7b033bdc622ad228
Patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Third Party Advisory