Bug 2373623 (CVE-2022-50212)

Summary: CVE-2022-50212 kernel: netfilter: nf_tables: do not allow CHAIN_ID to refer to another table
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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Description OSIDB Bzimport 2025-06-18 12:11:14 UTC 
In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: do not allow CHAIN_ID to refer to another table

When doing lookups for chains on the same batch by using its ID, a chain
from a different table can be used. If a rule is added to a table but
refers to a chain in a different table, it will be linked to the chain in
table2, but would have expressions referring to objects in table1.

Then, when table1 is removed, the rule will not be removed as its linked to
a chain in table2. When expressions in the rule are processed or removed,
that will lead to a use-after-free.

When looking for chains by ID, use the table that was used for the lookup
by name, and only return chains belonging to that same table.
Comment 1 Avinash Hanwate 2025-06-19 02:17:57 UTC 
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061844-CVE-2022-50212-1ff1@gregkh/T