CVE-2026-46107: dm-thin: fix metadata refcount underflow
Published May 28, 2026
·Updated
dm-thin: fix metadata refcount underflow
Affected Software
10 affected componentsFixes available
Linux Linux kernel
Linux Linux kernel>=3.2<5.10.259
Linux Linux kernel>=5.11<5.15.209
Linux Linux kernel>=5.16<6.1.175
Linux Linux kernel>=6.2<6.6.140
Linux Linux kernel>=6.7<6.12.88
Linux Linux kernel>=6.13<6.18.30
Linux Linux kernel>=6.19<7.0.7
Linux Linux kernel=7.1-rc1
Microsoft azl3 kernel 6.6.139.1-1<6.6.141.1-1
6.6.141.1-1
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade to a fixed release to a version that resolves this vulnerability.
Fixed in 6.6.141.1-1 - Configuration
Apply the upstream fix for the dm-thin rebalance_children metadata refcount underflow so that when the child btree node is shared (reference count > 1), the code increments reference counts on the grandchildren before decrementing the original child, preventing mismatched reference counts and 'device mapper: space map common: unable to decrement block' errors.
Linux kernel dm-thin rebalance_children (metadata refcount handling) = Increment reference counts on the grandchildren when copying/internal rebalancing shared btree nodes to prevent reference-count underflow
Event History
May 28, 2026
CVE Published
via MITRE·09:35 AM
Data Sourced
via MITRE·09:35 AM
DescriptionSeverity
Data Sourced
via NVD·10:16 AM
RemedyDescriptionSeverityWeaknessAffected Software
May 29, 2026
Data Sourced
via Microsoft·08:05 AM
DescriptionSeverityWeaknessAffected Software