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CVE-2025-40183
published 2025-11-12

CVE-2025-40183: 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…

PriorityP338high7.5CVSS 3.1
AVNACLPRNUINSUCNINAH
EPSS
0.57%
44.1th percentile
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.

Affected

29 ranges· showing 25
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
debianlinux-6.1< linux 6.1.158-1 (bookworm)linux 6.1.158-1 (bookworm)
linuxlinux
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 3fba965a9aac0fa3cbd8138436a37af9ab466d793fba965a9aac0fa3cbd8138436a37af9ab466d79
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 057764172fcc6ee2ccb6c41351a55a9f054dc8fd057764172fcc6ee2ccb6c41351a55a9f054dc8fd
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 2e67c2037382abb56497bb9d7b7e10be04eb55982e67c2037382abb56497bb9d7b7e10be04eb5598
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < b6bfe44b6dbb14a31d86c475cdc9c7689534fb09b6bfe44b6dbb14a31d86c475cdc9c7689534fb09
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < f36a305d30f557306d87c787ddffe094ac5dac89f36a305d30f557306d87c787ddffe094ac5dac89
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 7404ce888a45eb7da0508b7cbbe6f2e95302eeb87404ce888a45eb7da0508b7cbbe6f2e95302eeb8
linuxlinux>= b4ab31414970a7a03a5d55d75083f2c101a30592 < 23f3770e1a53e6c7a553135011f547209e141e7223f3770e1a53e6c7a553135011f547209e141e72
linuxlinux_kernel>= 0 < 5.10.247-15.10.247-1
linuxlinux_kernel>= 0 < 6.1.158-16.1.158-1
linuxlinux_kernel>= 0 < 6.12.57-16.12.57-1
linuxlinux_kernel>= 0 < 6.17.6-16.17.6-1
linuxlinux_kernel>= 0 < 5.15.0-170.1805.15.0-170.180
linuxlinux_kernel>= 0 < 6.8.0-106.1066.8.0-106.106
linuxlinux_kernel>= 0 < 6.17.0-14.146.17.0-14.14
linuxlinux_kernel>= 5.10.0 < 5.10.2465.10.246
linuxlinux_kernel>= 5.11.0 < 5.15.1955.15.195
linuxlinux_kernel>= 5.16.0 < 6.1.1576.1.157
linuxlinux_kernel>= 6.13.0 < 6.17.46.17.4
linuxlinux_kernel>= 6.2.0 < 6.6.1136.6.113
linuxlinux_kernel>= 6.7.0 < 6.12.546.12.54
ubuntulinux-aws
ubuntulinux-azure-5.15

CVSS provenance

nvdv3.17.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
osv7.8HIGH
vendor_ubuntu7.8HIGH
vendor_redhat4.4LOW
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