Description
In the Linux kernel, the following vulnerability has been resolved: bpf: Fix metadata_dst leak __bpf_redirect_neigh_v{4,6} Cilium has a BPF egress gateway feature which forces outgoing K8s Pod traffic to pass through dedicated egress gateways which then SNAT the traffic in order to interact with stable IPs outside the cluster. The traffic is directed to the gateway via vxlan tunnel in collect md mode. A recent BPF change utilized the bpf_redirect_neigh() helper to forward packets after the arrival and decap on vxlan, which turned out over time that the kmalloc-256 slab usage in kernel was ever-increasing. The issue was that vxlan allocates the metadata_dst object and attaches it through a fake dst entry to the skb. The latter was never released though given bpf_redirect_neigh() was merely setting the new dst entry via skb_dst_set() without dropping an existing one first.
Product status
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before 3fba965a9aac0fa3cbd8138436a37af9ab466d79
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before 057764172fcc6ee2ccb6c41351a55a9f054dc8fd
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before 2e67c2037382abb56497bb9d7b7e10be04eb5598
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before b6bfe44b6dbb14a31d86c475cdc9c7689534fb09
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before f36a305d30f557306d87c787ddffe094ac5dac89
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before 7404ce888a45eb7da0508b7cbbe6f2e95302eeb8
b4ab31414970a7a03a5d55d75083f2c101a30592 (git) before 23f3770e1a53e6c7a553135011f547209e141e72
5.10
Any version before 5.10
5.10.246 (semver)
5.15.195 (semver)
6.1.157 (semver)
6.6.113 (semver)
6.12.54 (semver)
6.17.4 (semver)
6.18 (original_commit_for_fix)
References
git.kernel.org/...c/3fba965a9aac0fa3cbd8138436a37af9ab466d79
git.kernel.org/...c/057764172fcc6ee2ccb6c41351a55a9f054dc8fd
git.kernel.org/...c/2e67c2037382abb56497bb9d7b7e10be04eb5598
git.kernel.org/...c/b6bfe44b6dbb14a31d86c475cdc9c7689534fb09
git.kernel.org/...c/f36a305d30f557306d87c787ddffe094ac5dac89
git.kernel.org/...c/7404ce888a45eb7da0508b7cbbe6f2e95302eeb8
git.kernel.org/...c/23f3770e1a53e6c7a553135011f547209e141e72
