CVE-2023-52935

Page table traversal is allowed under any one of the mmap lock, the anonvma lock (if the VMA is associated with an anonvma), and the mapping lock (if the VMA is associated with a mapping); and so to be able to remove page tables, we must hold all three of them. retractpagetables() bails out if an ->anon_vma is attached, but does this check before holding the mmap lock (as the comment above the check explains).

If we racily merged an existing ->anon_vma (shared with a child process) from a neighboring VMA, subsequent rmap traversals on pages belonging to the child will be able to see the page tables that we are concurrently removing while assuming that nothing else can access them.

Repeat the ->anon_vma check once we hold the mmap lock to ensure that there really is no concurrent page table access.

Hitting this bug causes a lockdep warning in collapseandfreepmd(), in the line "lockdepassertheldwrite(&vma->anon_vma->root->rwsem)". It can also lead to use-after-free access.

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

5.13.9-1~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

6.3.1-1~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

6.13~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

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

6.1.11-1

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

6.1.11-1

Ecosystem specific

{
    "urgency": "not yet assigned"
}