{ "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" } } } }