CVE-2024-35839
Description
In the Linux kernel, the following vulnerability has been resolved: netfilter: bridge: replace physindev with physinif in nf_bridge_info An skb can be added to a neigh->arp_queue while waiting for an arp reply. Where original skb's skb->dev can be different to neigh's neigh->dev. For instance in case of bridging dnated skb from one veth to another, the skb would be added to a neigh->arp_queue of the bridge. As skb->dev can be reset back to nf_bridge->physindev and used, and as there is no explicit mechanism that prevents this physindev from been freed under us (for instance neigh_flush_dev doesn't cleanup skbs from different device's neigh queue) we can crash on e.g. this stack: arp_process neigh_update skb = __skb_dequeue(&neigh->arp_queue) neigh_resolve_output(..., skb) ... br_nf_dev_xmit br_nf_pre_routing_finish_bridge_slow skb->dev = nf_bridge->physindev br_handle_frame_finish Let's use plain ifindex instead of net_device link. To peek into the original net_device we will use dev_get_by_index_rcu(). Thus either we get device and are safe to use it or we don't get it and drop skb.
Predictions
Heuristic predictions, AS-IS, for prioritization only.
Mitigations
No vendor mitigations ingested yet for this CVE. The mitigation-content worker queues fetches as references arrive — check back in a few minutes, or see the references list below.
OS impact
| OS | Version | Status | Fixed in |
|---|---|---|---|
| rhel | 9 | fixed | |
| rocky | 8 | fixed | |
| sles | affected | | |
| debian | bookworm | fixed | 6.1.76-1 |
| debian | bullseye | affected | |
| debian | forky | fixed | 6.6.15-1 |
| debian | sid | fixed | 6.6.15-1 |
| debian | trixie | fixed | 6.6.15-1 |
| almalinux | 9 | fixed | perf-5.14.0-427.33.1.el9_4.aarch64.rpm |
References
- https://access.redhat.com/errata/RHSA-2024:5928
- https://errata.rockylinux.org/RLSA-2024:8870
- https://errata.rockylinux.org/RLSA-2024:8856
- https://www.suse.com/security/cve/CVE-2024-35839.html
- https://security-tracker.debian.org/tracker/CVE-2024-35839
- https://bugzilla.redhat.com/2265185
- https://bugzilla.redhat.com/2272797
- https://bugzilla.redhat.com/2273654
- https://bugzilla.redhat.com/2275742
- https://bugzilla.redhat.com/2275744
- https://bugzilla.redhat.com/2277166
- https://bugzilla.redhat.com/2278256
- https://bugzilla.redhat.com/2278258
- https://bugzilla.redhat.com/2278264
- https://bugzilla.redhat.com/2281101
- https://bugzilla.redhat.com/2281284
- https://bugzilla.redhat.com/2281669
- https://bugzilla.redhat.com/2281672
- https://bugzilla.redhat.com/2281675
- https://bugzilla.redhat.com/2281916
- https://bugzilla.redhat.com/2281958
- https://bugzilla.redhat.com/2282720
- https://bugzilla.redhat.com/2283468
- https://bugzilla.redhat.com/2284421
- https://bugzilla.redhat.com/2293356
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Community-verified mitigations for this CVE will appear above when contributors publish them.
Verify integrity in audit chain (admin only). AS-IS.