CVE-2025-21806

Source
https://nvd.nist.gov/vuln/detail/CVE-2025-21806
Import Source
https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21806.json
JSON Data
https://api.osv.dev/v1/vulns/CVE-2025-21806
Downstream
Related
Published
2025-02-27T20:16:03Z
Modified
2025-07-29T11:19:09.335582Z
Summary
[none]
Details

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

net: let net.core.dev_weight always be non-zero

The following problem was encountered during stability test:

(NULL netdevice): NAPI poll function processbacklog+0x0/0x530 \ returned 1, exceeding its budget of 0. ------------[ cut here ]------------ listadd double add: new=ffff88905f746f48, prev=ffff88905f746f48, \ next=ffff88905f746e40. WARNING: CPU: 18 PID: 5462 at lib/listdebug.c:35 \ listaddvalidorreport+0xf3/0x130 CPU: 18 UID: 0 PID: 5462 Comm: ping Kdump: loaded Not tainted 6.13.0-rc7+ RIP: 0010:listaddvalidorreport+0xf3/0x130 Call Trace: ? _warn+0xcd/0x250 ? _listaddvalidorreport+0xf3/0x130 enqueuetobacklog+0x923/0x1070 netifrxinternal+0x92/0x2b0 _netifrx+0x15/0x170 loopbackxmit+0x2ef/0x450 devhardstartxmit+0x103/0x490 _devqueuexmit+0xeac/0x1950 ipfinishoutput2+0x6cc/0x1620 ipoutput+0x161/0x270 ippushpendingframes+0x155/0x1a0 rawsendmsg+0xe13/0x1550 _syssendto+0x3bf/0x4e0 _x64syssendto+0xdc/0x1b0 dosyscall64+0x5b/0x170 entrySYSCALL64after_hwframe+0x76/0x7e

The reproduction command is as follows: sysctl -w net.core.dev_weight=0 ping 127.0.0.1

This is because when the napi's weight is set to 0, processbacklog() may return 0 and clear the NAPISTATESCHED bit of napi->state, causing this napi to be re-polled in netrxaction() until _dosoftirq() times out. Since the NAPISTATESCHED bit has been cleared, napischedulerps() can be retriggered in enqueueto_backlog(), causing this issue.

Making the napi's weight always non-zero solves this problem.

Triggering this issue requires system-wide admin (setting is not namespaced).

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
Fixed
5.10.237-1

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

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
6.1.129-1

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

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
6.12.13-1

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
6.1.129-1~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

Ecosystem specific

{
    "urgency": "not yet assigned"
}