cve/2024/CVE-2024-56655.md
2025-09-29 21:09:30 +02:00

27 lines
2.8 KiB
Markdown

### [CVE-2024-56655](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2024-56655)
![](https://img.shields.io/static/v1?label=Product&message=Linux&color=blue)
![](https://img.shields.io/static/v1?label=Version&message=&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=558f503f707f481bbf40efa74a938b8021df841d%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=6.12%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=9eee6097ffb26cdd2adb988c0d378fa0d650c737%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=a394c160d57f4b083bd904a22802f6fb7f5b3cea%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=bfd05c68e4c6320304e9f371ffa356b6e4b9cc53%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=c03d278fdf35e73dd0ec543b9b556876b9d9a8dc%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=cb401e5799e0acacb405f2128097e9c4ccf82f8a%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Version&message=e6c32a64d61184c2bdf89442b3d31ef530afba34%20&color=brightgreen)
![](https://img.shields.io/static/v1?label=Vulnerability&message=n%2Fa&color=blue)
### Description
In the Linux kernel, the following vulnerability has been resolved:netfilter: nf_tables: do not defer rule destruction via call_rcunf_tables_chain_destroy can sleep, it can't be used from call_rcucallbacks.Moreover, nf_tables_rule_release() is only safe for error unwinding,while transaction mutex is held and the to-be-desroyed rule was notexposed to either dataplane or dumps, as it deactives+frees withoutthe required synchronize_rcu() in-between.nft_rule_expr_deactivate() callbacks will change ->use countersof other chains/sets, see e.g. nft_lookup .deactivate callback, thesemust 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 hardand 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_workRIP: 0010:nft_set_destroy+0x3fe/0x5c0Call Trace: <TASK> nf_tables_trans_destroy_work+0x6b7/0xad0 process_one_work+0x64a/0xce0 worker_thread+0x613/0x10d0In case the synchronize_rcu becomes an issue, we can explore alternatives.One way would be to allocate nft_trans_rule objects + one nft_trans_chainobject, deactivate the rules + the chain and then defer the freeing to thenft destroy workqueue. We'd still need to keep the synchronize_rcu path asa fallback to handle -ENOMEM corner cases though.
### POC
#### Reference
No PoCs from references.
#### Github
- https://github.com/cku-heise/euvd-api-doc
- https://github.com/fkie-cad/nvd-json-data-feeds