Linux Kernel up to 6.6.66/6.12.5 nf_tables_rule_release deserialization

Summaryinfo

A vulnerability classified as problematic has been found in Linux Kernel up to 6.6.66/6.12.5. Impacted is the function nf_tables_rule_release. The manipulation leads to deserialization. This vulnerability is uniquely identified as CVE-2024-56655. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.6.66/6.12.5. It has been rated as problematic. This issue affects the function nf_tables_rule_release. The manipulation with an unknown input leads to a deserialization vulnerability. Using CWE to declare the problem leads to CWE-502. The product deserializes untrusted data without sufficiently verifying that the resulting data will be valid. The impact remains unknown. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: netfilter: nf_tables: do not defer rule destruction via call_rcu nf_tables_chain_destroy can sleep, it can't be used from call_rcu callbacks. Moreover, nf_tables_rule_release() is only safe for error unwinding, while transaction mutex is held and the to-be-desroyed rule was not exposed to either dataplane or dumps, as it deactives+frees without the required synchronize_rcu() in-between. nft_rule_expr_deactivate() callbacks will change ->use counters of other chains/sets, see e.g. nft_lookup .deactivate callback, these must be serialized via transaction mutex. Also add a few lockdep asserts to make this more explicit. Calling synchronize_rcu() isn't ideal, but fixing this without is hard and way more intrusive. As-is, we can get: WARNING: .. net/netfilter/nf_tables_api.c:5515 nft_set_destroy+0x.. Workqueue: events nf_tables_trans_destroy_work RIP: 0010:nft_set_destroy+0x3fe/0x5c0 Call Trace: nf_tables_trans_destroy_work+0x6b7/0xad0 process_one_work+0x64a/0xce0 worker_thread+0x613/0x10d0 In case the synchronize_rcu becomes an issue, we can explore alternatives. One way would be to allocate nft_trans_rule objects + one nft_trans_chain object, deactivate the rules + the chain and then defer the freeing to the nft destroy workqueue. We'd still need to keep the synchronize_rcu path as a fallback to handle -ENOMEM corner cases though.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2024-56655 since 12/27/2024. The exploitation is known to be difficult. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 01/12/2026).

The vulnerability scanner Nessus provides a plugin with the ID 233479 (Ubuntu 24.10 : Linux kernel (Low Latency) vulnerabilities (USN-7380-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.6.67 or 6.12.6 eliminates this vulnerability. Applying the patch 27f0574253f6c24c8ee4e3f0a685b75ed3a256ed/7cf0bd232b565d9852cb25fd094f77254773e048/b04df3da1b5c6f6dc7cdccc37941740c078c4043 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (233479) and CERT Bund (WID-SEC-2024-3762). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• RESF Rocky Linux
• Dell NetWorker
• Dell Avamar
• Red Hat OpenShift
• IBM QRadar SIEM
• Dell PowerProtect Data Domain
• Open Source Linux Kernel
• IBM DataPower Gateway
• Dell Secure Connect Gateway

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.6.0
• 6.6.1
• 6.6.2
• 6.6.3
• 6.6.4
• 6.6.5
• 6.6.6
• 6.6.7
• 6.6.8
• 6.6.9
• 6.6.10
• 6.6.11
• 6.6.12
• 6.6.13
• 6.6.14
• 6.6.15
• 6.6.16
• 6.6.17
• 6.6.18
• 6.6.19
• 6.6.20
• 6.6.21
• 6.6.22
• 6.6.23
• 6.6.24
• 6.6.25
• 6.6.26
• 6.6.27
• 6.6.28
• 6.6.29
• 6.6.30
• 6.6.31
• 6.6.32
• 6.6.33
• 6.6.34
• 6.6.35
• 6.6.36
• 6.6.37
• 6.6.38
• 6.6.39
• 6.6.40
• 6.6.41
• 6.6.42
• 6.6.43
• 6.6.44
• 6.6.45
• 6.6.46
• 6.6.47
• 6.6.48
• 6.6.49
• 6.6.50
• 6.6.51
• 6.6.52
• 6.6.53
• 6.6.54
• 6.6.55
• 6.6.56
• 6.6.57
• 6.6.58
• 6.6.59
• 6.6.60
• 6.6.61
• 6.6.62
• 6.6.63
• 6.6.64
• 6.6.65
• 6.6.66
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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