CVE-2025-37953

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Source
https://nvd.nist.gov/vuln/detail/CVE-2025-37953
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-37953.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-37953
Downstream
Related
Published
2025-05-20T16:15:33Z
Modified
2025-08-13T01:03:40.984317Z
Summary
[none]
Details

In the Linux kernel, the following vulnerability has been resolved:

schhtb: make htbdeactivate() idempotent

Alan reported a NULL pointer dereference in htbnextrbnode() after we made htbqlen_notify() idempotent.

It turns out in the following case it introduced some regression:

htbdequeuetree(): |-> fqcodeldequeue() |-> qdisctreereducebacklog() |-> htbqlennotify() |-> htbdeactivate() |-> htbnextrbnode() |-> htbdeactivate()

For htbnextrbnode(), after calling the 1st htbdeactivate(), the clprio[prio]->ptr could be already set to NULL, which means htbnextrb_node() is vulnerable here.

For htbdeactivate(), although we checked qlen before calling it, in case of qlen==0 after qdisctreereducebacklog(), we may call it again which triggers the warning inside.

To fix the issues here, we need to:

1) Make htbdeactivate() idempotent, that is, simply return if we already call it before. 2) Make htbnextrbnode() safe against ptr==NULL.

Many thanks to Alan for testing and for the reproducer.

References

Affected packages

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
6.1.140-1

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

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
6.12.29-1

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
6.12.29-1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}

Debian:11 / linux-6.1

Package

Name
linux-6.1
Purl
pkg:deb/debian/linux-6.1?arch=source

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0Unknown introduced version / All previous versions are affected
Fixed
6.1.140-1~deb11u1

Affected versions

6.*

6.1.106-3~deb11u1
6.1.106-3~deb11u2
6.1.106-3~deb11u3
6.1.112-1~deb11u1
6.1.119-1~deb11u1
6.1.128-1~deb11u1
6.1.129-1~deb11u1
6.1.137-1~deb11u1

Ecosystem specific 

{
    "urgency": "not yet assigned"
}