CVE-2025-38350

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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
2025-07-19T07:15:22Z
Modified
2025-08-12T21:51:27.225820Z
Summary
[none]
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:127.0.0.1:8888

Since 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

Affected packages

Debian:11 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected

Affected versions

5.*

5.10.46-4
5.10.46-5
5.10.70-1~bpo10+1
5.10.70-1
5.10.84-1
5.10.92-1~bpo10+1
5.10.92-1
5.10.92-2
5.10.103-1~bpo10+1
5.10.103-1
5.10.106-1
5.10.113-1
5.10.120-1~bpo10+1
5.10.120-1
5.10.127-1
5.10.127-2~bpo10+1
5.10.127-2
5.10.136-1
5.10.140-1
5.10.148-1
5.10.149-1
5.10.149-2
5.10.158-1
5.10.158-2
5.10.162-1
5.10.178-1
5.10.178-2
5.10.178-3
5.10.179-1
5.10.179-2
5.10.179-3
5.10.179-4
5.10.179-5
5.10.191-1
5.10.197-1
5.10.205-1
5.10.205-2
5.10.209-1
5.10.209-2
5.10.216-1
5.10.218-1
5.10.221-1
5.10.223-1
5.10.226-1
5.10.234-1
5.10.237-1
5.13.9-1~exp1
5.13.9-1~exp2
5.13.12-1~exp1
5.14-1~exp1
5.14-1~exp2
5.14.1-1~exp1
5.14.2-1~exp1
5.14.3-1~exp1
5.14.6-1
5.14.6-2
5.14.6-3
5.14.9-1
5.14.9-2~bpo11+1
5.14.9-2
5.14.12-1
5.14.16-1
5.15-1~exp1
5.15.1-1~exp1
5.15.2-1~exp1
5.15.3-1
5.15.5-1
5.15.5-2~bpo11+1
5.15.5-2
5.15.15-1
5.15.15-2~bpo11+1
5.15.15-2
5.16~rc1-1~exp1
5.16~rc3-1~exp1
5.16~rc4-1~exp1
5.16~rc5-1~exp1
5.16~rc6-1~exp1
5.16~rc7-1~exp1
5.16~rc8-1~exp1
5.16.3-1~exp1
5.16.4-1~exp1
5.16.7-1
5.16.7-2
5.16.10-1
5.16.11-1~bpo11+1
5.16.11-1
5.16.12-1~bpo11+1
5.16.12-1
5.16.14-1
5.16.18-1
5.17~rc3-1~exp1
5.17~rc4-1~exp1
5.17~rc5-1~exp1
5.17~rc6-1~exp1
5.17~rc7-1~exp1
5.17~rc8-1~exp1
5.17.1-1~exp1
5.17.3-1
5.17.6-1
5.17.11-1
5.18-1~exp1
5.18.2-1~bpo11+1
5.18.2-1
5.18.5-1
5.18.14-1~bpo11+1
5.18.14-1
5.18.16-1~bpo11+1
5.18.16-1
5.19~rc4-1~exp1
5.19~rc6-1~exp1
5.19-1~exp1
5.19.6-1
5.19.11-1~bpo11+1
5.19.11-1

6.*

6.0~rc7-1~exp1
6.0-1~exp1
6.0.2-1
6.0.3-1~bpo11+1
6.0.3-1
6.0.5-1
6.0.6-1
6.0.6-2
6.0.7-1
6.0.8-1
6.0.10-1
6.0.10-2
6.0.12-1~bpo11+1
6.0.12-1
6.0.12-1+alpha
6.1~rc3-1~exp1
6.1~rc5-1~exp1
6.1~rc6-1~exp1
6.1~rc7-1~exp1
6.1~rc8-1~exp1
6.1.1-1~exp1
6.1.1-1~exp2
6.1.2-1~exp1
6.1.4-1
6.1.7-1
6.1.8-1
6.1.8-1+sh4
6.1.11-1
6.1.12-1~bpo11+1
6.1.12-1
6.1.15-1~bpo11+1
6.1.15-1
6.1.20-1~bpo11+1
6.1.20-1
6.1.20-2~bpo11+1
6.1.20-2
6.1.25-1
6.1.27-1~bpo11+1
6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.1.135-1
6.1.137-1
6.1.139-1
6.1.140-1
6.1.147-1
6.3.1-1~exp1
6.3.2-1~exp1
6.3.4-1~exp1
6.3.5-1~exp1
6.3.7-1~bpo12+1
6.3.7-1
6.3.11-1
6.4~rc6-1~exp1
6.4~rc7-1~exp1
6.4.1-1~exp1
6.4.4-1~bpo12+1
6.4.4-1
6.4.4-2
6.4.4-3~bpo12+1
6.4.4-3
6.4.11-1
6.4.13-1
6.5~rc4-1~exp1
6.5~rc6-1~exp1
6.5~rc7-1~exp1
6.5.1-1~exp1
6.5.3-1~bpo12+1
6.5.3-1
6.5.6-1
6.5.8-1
6.5.10-1~bpo12+1
6.5.10-1
6.5.13-1
6.6.3-1~exp1
6.6.4-1~exp1
6.6.7-1~exp1
6.6.8-1
6.6.9-1
6.6.11-1
6.6.13-1~bpo12+1
6.6.13-1
6.6.15-1
6.6.15-2
6.7-1~exp1
6.7.1-1~exp1
6.7.4-1~exp1
6.7.7-1
6.7.9-1
6.7.9-2
6.7.12-1~bpo12+1
6.7.12-1
6.8.9-1
6.8.11-1
6.8.12-1~bpo12+1
6.8.12-1
6.9.2-1~exp1
6.9.7-1~bpo12+1
6.9.7-1
6.9.8-1
6.9.9-1
6.9.10-1~bpo12+1
6.9.10-1
6.9.11-1
6.9.12-1
6.10-1~exp1
6.10.1-1~exp1
6.10.3-1
6.10.4-1
6.10.6-1~bpo12+1
6.10.6-1
6.10.7-1
6.10.9-1
6.10.11-1~bpo12+1
6.10.11-1
6.10.12-1
6.11~rc4-1~exp1
6.11~rc5-1~exp1
6.11-1~exp1
6.11.2-1
6.11.4-1
6.11.5-1~bpo12+1
6.11.5-1
6.11.6-1
6.11.7-1
6.11.9-1
6.11.10-1~bpo12+1
6.11.10-1
6.12~rc6-1~exp1
6.12.3-1
6.12.5-1
6.12.6-1
6.12.8-1
6.12.9-1~bpo12+1
6.12.9-1
6.12.9-1+alpha
6.12.10-1
6.12.11-1
6.12.11-1+alpha
6.12.11-1+alpha.1
6.12.12-1~bpo12+1
6.12.12-1
6.12.13-1
6.12.15-1
6.12.16-1
6.12.17-1
6.12.19-1
6.12.20-1
6.12.21-1
6.12.22-1~bpo12+1
6.12.22-1
6.12.25-1
6.12.27-1~bpo12+1
6.12.27-1
6.12.29-1
6.12.30-1~bpo12+1
6.12.30-1
6.12.31-1
6.12.32-1~bpo12+1
6.12.32-1
6.12.33-1~bpo12+1
6.12.33-1
6.12.35-1~bpo12+1
6.12.35-1
6.12.37-1
6.12.38-1~bpo12+1
6.12.38-1
6.13~rc6-1~exp1
6.13~rc7-1~exp1
6.13.2-1~exp1
6.13.3-1~exp1
6.13.4-1~exp1
6.13.5-1~exp1
6.13.6-1~exp1
6.13.7-1~exp1
6.13.8-1~exp1
6.13.9-1~exp1
6.13.10-1~exp1
6.13.11-1~exp1
6.14.3-1~exp1
6.14.5-1~exp1
6.14.6-1~exp1
6.15~rc7-1~exp1
6.15-1~exp1
6.15.1-1~exp1
6.15.2-1~exp1
6.15.3-1~exp1
6.15.4-1~exp1
6.15.5-1~exp1
6.15.6-1~exp1
6.16~rc7-1~exp1
6.16-1~exp1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:12 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.1.147-1

Affected versions

6.*

6.1.27-1
6.1.37-1
6.1.38-1
6.1.38-2~bpo11+1
6.1.38-2
6.1.38-3
6.1.38-4~bpo11+1
6.1.38-4
6.1.52-1
6.1.55-1~bpo11+1
6.1.55-1
6.1.64-1
6.1.66-1
6.1.67-1
6.1.69-1~bpo11+1
6.1.69-1
6.1.76-1~bpo11+1
6.1.76-1
6.1.82-1
6.1.85-1
6.1.90-1~bpo11+1
6.1.90-1
6.1.94-1~bpo11+1
6.1.94-1
6.1.98-1
6.1.99-1
6.1.106-1
6.1.106-2
6.1.106-3
6.1.112-1
6.1.115-1
6.1.119-1
6.1.123-1
6.1.124-1
6.1.128-1
6.1.129-1
6.1.133-1
6.1.135-1
6.1.137-1
6.1.139-1
6.1.140-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:13 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.37-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:14 / linux

Package

Name
linux
Purl
pkg:deb/debian/linux?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.12.37-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}