{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-39872","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2025-04-16T07:20:57.144Z","datePublished":"2025-09-23T06:00:45.528Z","dateUpdated":"2026-08-05T12:05:48.806Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T12:05:48.806Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nhsr: hold rcu and dev lock for hsr_get_port_ndev\n\nhsr_get_port_ndev calls hsr_for_each_port, which need to hold rcu lock.\nOn the other hand, before return the port device, we need to hold the\ndevice reference to avoid UaF in the caller function."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable path is entered from local socket/netlink operations — a multicast group join on the HSR master propagates via `hsr_set_rx_mode()` to the ICSSG slave's `ndo_set_rx_mode`, which queues the work that calls `hsr_get_port_ndev()`. A remote peer on the HSR ring cannot induce multicast address changes or HSR port reconfiguration, so this is not network-reachable.\nAC:L - The attacker fully controls the traversal side of the race by looping `IP_ADD_MEMBERSHIP`/`IP_DROP_MEMBERSHIP` to repeatedly queue `emac_ndo_set_rx_mode_work`, and the walk runs in preemptible process context with no RCU or RTNL held, so no tight timing window must be won — only overlap with a port-list mutation, which can be retried indefinitely.\nPR:L - Triggering the vulnerable `hsr_get_port_ndev()` traversal requires only an ordinary unprivileged UDP socket performing a multicast group join on the HSR interface; no capability check exists anywhere on that path. Widening the race window via HSR port reconfiguration needs only CAP_NET_ADMIN, which per kernel CNA guidance is scored as Low.\nUI:N - The entire sequence is driven by the attacker's own socket operations against an already-configured HSR-offload interface. No victim action is needed.\nS:U - The use-after-free corrupts kernel memory within the same kernel security authority; there is no VM, IOMMU, or sandbox boundary crossed.\nC:H - The unlocked RCU walk dereferences a freed `hsr_port` and the returned `net_device` is used without a reference, and `netdev_priv()` on that freed device is read as a `prueth_emac` — a use-after-free read whose contents the attacker can groom via heap spray, yielding kernel memory disclosure and pointer leakage.\nI:H - `icssg_fdb_setup()` performs `++(emac->prueth->icssg_hwcmdseq)` — a pointer loaded out of the freed object and then written through — plus further writes into PRU shared memory at addresses derived from freed data, giving a controllable write primitive suitable for control-flow hijacking after heap reuse.\nA:H - Following a `kfree_rcu()`-freed list node and dereferencing a freed `net_device` reliably produces an oops/panic (and slab corruption) even when not exploited further, and the attacker can retrigger it repeatedly on an industrial redundancy device."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/ti/icssg/icssg_prueth.c","net/hsr/hsr_device.c"],"versions":[{"version":"ef964411c8ca775967355d855abc56aeaca3c867","lessThan":"9433ba79c2ec3ec7c9a711748701549339c3438c","status":"affected","versionType":"git"},{"version":"9c10dd8eed74de9e8adeb820939f8745cd566d4a","lessThan":"68a6729afd3e8e9a2a32538642ce92b96ccf9b1d","status":"affected","versionType":"git"},{"version":"9c10dd8eed74de9e8adeb820939f8745cd566d4a","lessThan":"847748fc66d08a89135a74e29362a66ba4e3ab15","status":"affected","versionType":"git"},{"version":"6.12.63","lessThan":"6.12.64","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/ethernet/ti/icssg/icssg_prueth.c","net/hsr/hsr_device.c"],"versions":[{"version":"6.14","status":"affected"},{"version":"0","lessThan":"6.14","status":"unaffected","versionType":"semver"},{"version":"6.12.64","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.16.8","lessThanOrEqual":"6.16.*","status":"unaffected","versionType":"semver"},{"version":"6.17","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.63","versionEndExcluding":"6.12.64"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.16.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.14","versionEndExcluding":"6.17"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/9433ba79c2ec3ec7c9a711748701549339c3438c"},{"url":"https://git.kernel.org/stable/c/68a6729afd3e8e9a2a32538642ce92b96ccf9b1d"},{"url":"https://git.kernel.org/stable/c/847748fc66d08a89135a74e29362a66ba4e3ab15"}],"title":"hsr: hold rcu and dev lock for hsr_get_port_ndev","x_generator":{"engine":"bippy-1.2.0"}}}}