netfilter: nf_tables: don't skip expired elements during walk
There is an asymmetry between commit/abort and preparation phase if the
following conditions are met:
1. set is a verdict map ("1.2.3.4 : jump foo")
2. timeouts are enabled
In this case, following sequence is problematic:
1. element E in set S refers to chain C
2. userspace requests removal of set S
3. kernel does a set walk to decrement chain->use count for all elements
from preparation phase
4. kernel does another set walk to remove elements from the commit phase
(or another walk to do a chain->use increment for all elements from
abort phase)
If E has already expired in 1), it will be ignored during list walk, so its use count
won't have been changed.
Then, when set is culled, ->destroy callback will zap the element via
nf_tables_set_elem_destroy(), but this function is only safe for
elements that have been deactivated earlier from the preparation phase:
lack of earlier deactivate removes the element but leaks the chain use
count, which results in a WARN splat when the chain gets removed later,
plus a leak of the nft_chain structure.
Update pipapo_get() not to skip expired elements, otherwise flush
command reports bogus ENOENT errors.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Linux |
|
No data.
No data.
OpenCVE Enrichment is a feature of OpenCVE that uses AI to automatically link vendors and products to CVEs. Learn more on GitHub.
| Vendors | Products |
|---|---|
| Linux |
|
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Wed, 16 Jul 2025 13:45:00 +0000
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| Metrics |
epss
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epss
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Thu, 13 Feb 2025 01:00:00 +0000
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|---|---|---|
| Weaknesses | CWE-664 | |
| Metrics |
threat_severity
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threat_severity
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Fri, 07 Feb 2025 14:00:00 +0000
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| References |
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| Metrics |
threat_severity
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cvssV3_1
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Wed, 05 Feb 2025 09:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: don't skip expired elements during walk There is an asymmetry between commit/abort and preparation phase if the following conditions are met: 1. set is a verdict map ("1.2.3.4 : jump foo") 2. timeouts are enabled In this case, following sequence is problematic: 1. element E in set S refers to chain C 2. userspace requests removal of set S 3. kernel does a set walk to decrement chain->use count for all elements from preparation phase 4. kernel does another set walk to remove elements from the commit phase (or another walk to do a chain->use increment for all elements from abort phase) If E has already expired in 1), it will be ignored during list walk, so its use count won't have been changed. Then, when set is culled, ->destroy callback will zap the element via nf_tables_set_elem_destroy(), but this function is only safe for elements that have been deactivated earlier from the preparation phase: lack of earlier deactivate removes the element but leaks the chain use count, which results in a WARN splat when the chain gets removed later, plus a leak of the nft_chain structure. Update pipapo_get() not to skip expired elements, otherwise flush command reports bogus ENOENT errors. | |
| Title | netfilter: nf_tables: don't skip expired elements during walk | |
| References |
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MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:46:06.745Z
Reserved: 2024-08-21T06:07:11.018Z
Link: CVE-2023-52924
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-02-05T10:15:21.073
Modified: 2025-02-05T10:15:21.073
Link: CVE-2023-52924
Redhat
OpenCVE Enrichment
Updated: 2025-07-13T21:06:39Z