CVE-2022-49086

Source
https://nvd.nist.gov/vuln/detail/CVE-2022-49086
Import Source
https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2022-49086.json
JSON Data
https://api.test.osv.dev/v1/vulns/CVE-2022-49086
Related
Published
2025-02-26T07:00:45Z
Modified
2025-02-26T19:02:51.139468Z
Summary
[none]
Details

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

net: openvswitch: fix leak of nested actions

While parsing user-provided actions, openvswitch module may dynamically allocate memory and store pointers in the internal copy of the actions. So this memory has to be freed while destroying the actions.

Currently there are only two such actions: ct() and set(). However, there are many actions that can hold nested lists of actions and ovsnlafreeflowactions() just jumps over them leaking the memory.

For example, removal of the flow with the following actions will lead to a leak of the memory allocated by nfcttmpl_alloc():

actions:clone(ct(commit),0)

Non-freed set() action may also leak the 'dst' structure for the tunnel info including device references.

Under certain conditions with a high rate of flow rotation that may cause significant memory leak problem (2MB per second in reporter's case). The problem is also hard to mitigate, because the user doesn't have direct control over the datapath flows generated by OVS.

Fix that by iterating over all the nested actions and freeing everything that needs to be freed recursively.

New build time assertion should protect us from this problem if new actions will be added in the future.

Unfortunately, openvswitch module doesn't use NLAFNESTED, so all attributes has to be explicitly checked. sample() and clone() actions are mixing extra attributes into the user-provided action list. That prevents some code generalization too.

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
5.10.113-1

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

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
5.17.3-1

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
5.17.3-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}