CVE-2025-38350
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2025-38350
- Import Source
- https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2025-38350.json
- JSON Data
- https://api.test.osv.dev/v1/vulns/CVE-2025-38350
- Downstream
- Related
- Published
- 2025-07-19T06:46:29Z
- Modified
- 2025-10-10T15:22:55.222477Z
- Summary
- net/sched: Always pass notifications when child class becomes empty
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
net/sched: Always pass notifications when child class becomes empty
Certain classful qdiscs may invoke their classes' dequeue handler on an enqueue operation. This may unexpectedly empty the child qdisc and thus make an in-flight class passive via qlen_notify(). Most qdiscs do not expect such behaviour at this point in time and may re-activate the class eventually anyways which will lead to a use-after-free.
The referenced fix commit attempted to fix this behavior for the HFSC case by moving the backlog accounting around, though this turned out to be incomplete since the parent's parent may run into the issue too. The following reproducer demonstrates this use-after-free:
tc qdisc add dev lo root handle 1: drr tc filter add dev lo parent 1: basic classid 1:1 tc class add dev lo parent 1: classid 1:1 drr tc qdisc add dev lo parent 1:1 handle 2: hfsc def 1 tc class add dev lo parent 2: classid 2:1 hfsc rt m1 8 d 1 m2 0 tc qdisc add dev lo parent 2:1 handle 3: netem tc qdisc add dev lo parent 3:1 handle 4: blackhole echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888 tc class delete dev lo classid 1:1 echo 1 | socat -u STDIN UDP4-DATAGRAM:127.0.0.1:8888Since backlog accounting issues leading to a use-after-frees on stale class pointers is a recurring pattern at this point, this patch takes a different approach. Instead of trying to fix the accounting, the patch ensures that qdisctreereducebacklog always calls qlennotify when the child qdisc is empty. This solves the problem because deletion of qdiscs always involves a call to qdiscreset() and / or qdiscpurgequeue() which ultimately resets its qlen to 0 thus causing the following qdisctreereducebacklog() to report to the parent. Note that this may call qlennotify on passive classes multiple times. This is not a problem after the recent patch series that made all the classful qdiscs qlennotify() handlers idempotent.
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/103406b38c600fec1fe375a77b27d87e314aea09
- https://git.kernel.org/stable/c/3b290923ad2b23596208c1e29520badef4356a43
- https://git.kernel.org/stable/c/7874c9c132e906a52a187d045995b115973c93fb
- https://git.kernel.org/stable/c/a44acdd9e84a211989ff4b9b92bf3545d8456ad5
- https://git.kernel.org/stable/c/a553afd91f55ff39b1e8a1c4989a29394c9e0472
- https://git.kernel.org/stable/c/e269f29e9395527bc00c213c6b15da04ebb35070
- https://git.kernel.org/stable/c/e9921b57dca05ac5f4fa1fa8e993d4f0ee52e2b7
- https://git.kernel.org/stable/c/f680a4643c6f71e758d8fe0431a958e9a6a4f59d
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced1034e3310752e8675e313f7271b348914008719aFixed3b290923ad2b23596208c1e29520badef4356a43
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedf9f593e34d2fb67644372c8f7b033bdc622ad228Fixede9921b57dca05ac5f4fa1fa8e993d4f0ee52e2b7
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced89c301e929a0db14ebd94b4d97764ce1d6981653Fixede269f29e9395527bc00c213c6b15da04ebb35070
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedf1dde3eb17dc1b8bd07aed00004b1e05fc87a3d4Fixed7874c9c132e906a52a187d045995b115973c93fb
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced93c276942e75de0e5bc91576300d292e968f5a02Fixedf680a4643c6f71e758d8fe0431a958e9a6a4f59d
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced49b21795b8e5654a7df3d910a12e1060da4c04cfFixeda553afd91f55ff39b1e8a1c4989a29394c9e0472
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3f981138109f63232a5fb7165938d4c945cc1b9dFixeda44acdd9e84a211989ff4b9b92bf3545d8456ad5
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3f981138109f63232a5fb7165938d4c945cc1b9dFixed103406b38c600fec1fe375a77b27d87e314aea09
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introduced3f3a22eebbc32b4fa8ce9c1d5f9db214b45b9335
Affected versions
v5.*
v5.10.1
v5.10.10
v5.10.11
v5.10.12
v5.10.13
v5.10.14
v5.10.15
v5.10.16
v5.10.17
v5.10.18
v5.10.19
v5.10.2
v5.10.238
v5.10.239
v5.10.3
v5.10.4
v5.10.5
v5.10.6
v5.10.7
v5.10.8
v5.10.9
v5.11.1
v5.11.10
v5.11.11
v5.11.12
v5.11.13
v5.11.14
v5.11.15
v5.11.16
v5.11.17
v5.11.18
v5.11.19
v5.11.2
v5.11.20
v5.11.21
v5.11.3
v5.11.4
v5.11.5
v5.11.6
v5.11.7
v5.11.8
v5.11.9
v5.12.1
v5.12.10
v5.12.11
v5.12.12
v5.12.13
v5.12.14
v5.12.15
v5.12.16
v5.12.17
v5.12.18
v5.12.19
v5.12.2
v5.12.3
v5.12.4
v5.12.5
v5.12.6
v5.12.7
v5.12.8
v5.12.9
v5.13.1
v5.13.10
v5.13.11
v5.13.12
v5.13.13
v5.13.14
v5.13.15
v5.13.16
v5.13.17
v5.13.18
v5.13.2
v5.13.3
v5.13.4
v5.13.5
v5.13.6
v5.13.7
v5.13.8
v5.13.9
v5.14.1
v5.14.10
v5.14.11
v5.14.12
v5.14.13
v5.14.14
v5.14.15
v5.14.16
v5.14.17
v5.14.18
v5.14.19
v5.14.2
v5.14.20
v5.14.3
v5.14.4
v5.14.5
v5.14.6
v5.14.7
v5.14.8
v5.14.9
v5.15.1
v5.15.10
v5.15.11
v5.15.12
v5.15.13
v5.15.14
v5.15.15
v5.15.16
v5.15.17
v5.15.18
v5.15.185
v5.15.186
v5.15.19
v5.15.2
v5.15.3
v5.15.4
v5.15.5
v5.15.6
v5.15.7
v5.15.8
v5.15.9
v5.16.1
v5.16.10
v5.16.11
v5.16.12
v5.16.13
v5.16.14
v5.16.15
v5.16.16
v5.16.17
v5.16.18
v5.16.19
v5.16.2
v5.16.20
v5.16.3
v5.16.4
v5.16.5
v5.16.6
v5.16.7
v5.16.8
v5.16.9
v5.17.1
v5.17.10
v5.17.11
v5.17.12
v5.17.13
v5.17.14
v5.17.2
v5.17.3
v5.17.4
v5.17.5
v5.17.6
v5.17.7
v5.17.8
v5.17.9
v5.18.1
v5.18.10
v5.18.11
v5.18.12
v5.18.13
v5.18.14
v5.18.15
v5.18.16
v5.18.17
v5.18.18
v5.18.19
v5.18.2
v5.18.3
v5.18.4
v5.18.5
v5.18.6
v5.18.7
v5.18.8
v5.18.9
v5.19.1
v5.19.10
v5.19.11
v5.19.12
v5.19.13
v5.19.14
v5.19.15
v5.19.16
v5.19.2
v5.19.3
v5.19.4
v5.19.5
v5.19.6
v5.19.7
v5.19.8
v5.19.9
v5.4.294
v5.4.295
v5.6.1
v5.6.10
v5.6.11
v5.6.12
v5.6.13
v5.6.14
v5.6.15
v5.6.16
v5.6.17
v5.6.18
v5.6.2
v5.6.3
v5.6.4
v5.6.5
v5.6.6
v5.6.7
v5.6.8
v5.6.9
v5.7.1
v5.7.10
v5.7.11
v5.7.12
v5.7.13
v5.7.14
v5.7.15
v5.7.16
v5.7.2
v5.7.3
v5.7.4
v5.7.5
v5.7.6
v5.7.7
v5.7.8
v5.7.9
v5.8.1
v5.8.10
v5.8.11
v5.8.12
v5.8.13
v5.8.14
v5.8.15
v5.8.16
v5.8.17
v5.8.18
v5.8.2
v5.8.3
v5.8.4
v5.8.5
v5.8.6
v5.8.7
v5.8.8
v5.8.9
v5.9.1
v5.9.10
v5.9.11
v5.9.12
v5.9.13
v5.9.14
v5.9.15
v5.9.16
v5.9.2
v5.9.3
v5.9.4
v5.9.5
v5.9.6
v5.9.7
v5.9.8
v5.9.9
v6.*
v6.0.1
v6.0.10
v6.0.11
v6.0.12
v6.0.13
v6.0.14
v6.0.15
v6.0.16
v6.0.17
v6.0.18
v6.0.2
v6.0.3
v6.0.4
v6.0.5
v6.0.6
v6.0.7
v6.0.8
v6.0.9
v6.1.1
v6.1.10
v6.1.11
v6.1.12
v6.1.13
v6.1.14
v6.1.141
v6.1.142
v6.1.143
v6.1.15
v6.1.2
v6.1.3
v6.1.4
v6.1.5
v6.1.6
v6.1.7
v6.1.8
v6.1.9
v6.10.1
v6.10.10
v6.10.11
v6.10.12
v6.10.13
v6.10.2
v6.10.3
v6.10.4
v6.10.5
v6.10.6
v6.10.7
v6.10.8
v6.10.9
v6.11.1
v6.11.10
v6.11.11
v6.11.2
v6.11.3
v6.11.4
v6.11.5
v6.11.6
v6.11.7
v6.11.8
v6.11.9
v6.12.1
v6.12.10
v6.12.11
v6.12.12
v6.12.13
v6.12.14
v6.12.2
v6.12.3
v6.12.31
v6.12.32
v6.12.33
v6.12.34
v6.12.35
v6.12.36
v6.12.4
v6.12.5
v6.12.6
v6.12.7
v6.12.8
v6.12.9
v6.13.1
v6.13.10
v6.13.11
v6.13.12
v6.13.2
v6.13.3
v6.13.4
v6.13.5
v6.13.6
v6.13.7
v6.13.8
v6.13.9
v6.14.10
v6.14.11
v6.14.9
v6.15
v6.15-rc1
v6.15-rc2
v6.15-rc3
v6.15-rc4
v6.15-rc5
v6.15-rc6
v6.15-rc7
v6.15.1
v6.15.10
v6.15.11
v6.15.2
v6.15.3
v6.15.4
v6.15.5
v6.15.6
v6.15.7
v6.15.8
v6.15.9
v6.16
v6.16-rc1
v6.16-rc2
v6.16-rc3
v6.16-rc4
v6.16-rc5
v6.16-rc6
v6.16-rc7
v6.16.1
v6.16.10
v6.16.11
v6.16.2
v6.16.3
v6.16.4
v6.16.5
v6.16.6
v6.16.7
v6.16.8
v6.16.9
v6.2.1
v6.2.10
v6.2.11
v6.2.12
v6.2.13
v6.2.14
v6.2.15
v6.2.2
v6.2.3
v6.2.4
v6.2.5
v6.2.6
v6.2.7
v6.2.8
v6.2.9
v6.3.1
v6.3.10
v6.3.11
v6.3.12
v6.3.2
v6.3.3
v6.3.4
v6.3.5
v6.3.6
v6.3.7
v6.3.8
v6.3.9
v6.4.1
v6.4.10
v6.4.11
v6.4.12
v6.4.13
v6.4.14
v6.4.15
v6.4.16
v6.4.2
v6.4.3
v6.4.4
v6.4.5
v6.4.6
v6.4.7
v6.4.8
v6.4.9
v6.5.1
v6.5.10
v6.5.11
v6.5.12
v6.5.13
v6.5.2
v6.5.3
v6.5.4
v6.5.5
v6.5.6
v6.5.7
v6.5.8
v6.5.9
v6.6.1
v6.6.10
v6.6.11
v6.6.12
v6.6.13
v6.6.14
v6.6.2
v6.6.3
v6.6.4
v6.6.5
v6.6.6
v6.6.7
v6.6.8
v6.6.9
v6.6.93
v6.6.94
v6.6.95
v6.6.96
v6.7.1
v6.7.10
v6.7.11
v6.7.2
v6.7.3
v6.7.4
v6.7.5
v6.7.6
v6.7.7
v6.7.8
v6.7.9
v6.8.1
v6.8.10
v6.8.11
v6.8.2
v6.8.3
v6.8.4
v6.8.5
v6.8.6
v6.8.7
v6.8.8
v6.8.9
v6.9.1
v6.9.10
v6.9.11
v6.9.12
v6.9.2
v6.9.3
v6.9.4
v6.9.5
v6.9.6
v6.9.7
v6.9.8
v6.9.9
Linux / Kernel
Package
- Name
- Kernel
Affected ranges
- Type
- ECOSYSTEM
- Events
-
Introduced0Unknown introduced version / All previous versions are affectedFixed5.4.296
- Type
- ECOSYSTEM
- Events
-
Introduced5.5.0Fixed5.10.240
- Type
- ECOSYSTEM
- Events
-
Introduced5.11.0Fixed5.15.187
- Type
- ECOSYSTEM
- Events
-
Introduced5.16.0Fixed6.1.144
- Type
- ECOSYSTEM
- Events
-
Introduced6.2.0Fixed6.6.97
- Type
- ECOSYSTEM
- Events
-
Introduced6.7.0Fixed6.12.37
- Type
- ECOSYSTEM
- Events
-
Introduced6.13.0Fixed6.15.6