CVE-2024-36891

Currently the code calls masstart() followed by masdataend() if the maple state is MASTART, but masstart() may return with the maple state node == NULL. This will lead to a null pointer dereference when checking information in the NULL node, which is done in masdata_end().

Avoid setting the offset if there is no node by waiting until after the maple state is checked for an empty or single entry state.

A user could trigger the events to cause a kernel oops by unmapping all vmas to produce an empty maple tree, then mapping a vma that would cause the scenario described above.

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

6.1.94-1

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

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

6.8.11-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}