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.
No advisories yet.
Solution
No solution given by the vendor.
Workaround
No workaround given by the vendor.
Wed, 15 Oct 2025 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | NVD-CWE-noinfo | |
| CPEs | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc2:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc3:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc4:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.5:rc5:*:*:*:*:*:* |
Wed, 16 Jul 2025 13:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
epss
|
epss
|
Thu, 13 Feb 2025 01:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-664 | |
| Metrics |
threat_severity
|
threat_severity
|
Fri, 07 Feb 2025 14:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
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 |
|
|
Projects
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Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T07:46:06.745Z
Reserved: 2024-08-21T06:07:11.018Z
Link: CVE-2023-52924
No data.
Status : Analyzed
Published: 2025-02-05T10:15:21.073
Modified: 2025-10-15T20:04:35.060
Link: CVE-2023-52924
OpenCVE Enrichment
Updated: 2025-07-13T21:06:39Z