{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38270", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.998Z", "datePublished": "2025-07-10T07:41:52.475Z", "dateUpdated": "2026-08-05T12:00:52.836Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:52.836Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: drv: netdevsim: don't napi_complete() from netpoll\n\nnetdevsim supports netpoll. Make sure we don't call napi_complete()\nfrom it, since it may not be scheduled. Breno reports hitting a\nwarning in napi_complete_done():\n\nWARNING: CPU: 14 PID: 104 at net/core/dev.c:6592 napi_complete_done+0x2cc/0x560\n __napi_poll+0x2d8/0x3a0\n handle_softirqs+0x1fe/0x710\n\nThis is presumably after netpoll stole the SCHED bit prematurely." } ], "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 - netdevsim is a purely software-simulated netdev with no physical link; the vulnerable `nsim_poll()` is reached by transmitting on a local netdevsim interface (`nsim_start_xmit` → `nsim_napi_rx` → `napi_schedule`) or via a locally configured netconsole/netpoll. There is no path from unsolicited remote traffic in a default configuration.\nAC:L - The attacker fully controls both the trigger and the race: queuing ≥64 skbs on one RX ring makes `nsim_rcv()` return the full budget deterministically, and concurrent `napi_schedule()` from a second thread on another CPU is trivially arranged by multi-threaded sending. No condition depends on state outside the attacker's influence.\nPR:L - Given a netdevsim interface present in the attacker's network namespace (a routine setup on CI/test hosts and in admin-provisioned containers), an ordinary unprivileged local user can drive the RX ring to full budget simply by sending packets — no capability check guards `nsim_start_xmit()` or the NAPI poll path.\nUI:N - The condition is triggered entirely by the attacker's own packet transmission and softirq NAPI processing; no victim action of any kind is needed.\nS:U - The corrupted state (NAPI `state` bits, `poll_list`, GRO lists) and the resulting impact are all within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - Clearing `NAPIF_STATE_SCHED` while still owning the instance destroys NAPI's only mutual-exclusion guarantee (netpoll_poll_lock is a no-op without netpoll), allowing two CPUs to run the same NAPI concurrently over shared `napi->gro` and skb lists; the resulting list corruption/UAF is leverageable to read adjacent kernel memory.\nI:H - A `list_add_tail()` of an already-linked `poll_list` node onto a second CPU's poll list is an unlinked-pointer write into kernel list structures, and concurrent GRO/skb-queue manipulation yields further heap corruption — both classic primitives for controlled kernel memory writes.\nA:H - The reported symptom is a `WARN_ON_ONCE` in `napi_complete_done()` (fatal under `panic_on_warn`), and the NAPI-state desync additionally causes list corruption, `pr_crit` under `CONFIG_DEBUG_NET`, softirq loops, and oopses that take down the machine." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/netdevsim/netdev.c" ], "versions": [ { "version": "3762ec05a9fbda16aaaa2568df679ab8ad13f38d", "lessThan": "a8ff2e362d901200a1075c3ca9c56d9c7bbef389", "status": "affected", "versionType": "git" }, { "version": "3762ec05a9fbda16aaaa2568df679ab8ad13f38d", "lessThan": "6837dd877270c57689bd866de9f3de14172c2439", "status": "affected", "versionType": "git" }, { "version": "3762ec05a9fbda16aaaa2568df679ab8ad13f38d", "lessThan": "1264971017b4d7141352a7fe29021bdfce5d885d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/netdevsim/netdev.c" ], "versions": [ { "version": "6.10", "status": "affected" }, { "version": "0", "lessThan": "6.10", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.34", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.3", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "6.10", "versionEndExcluding": "6.12.34" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.15.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.10", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a8ff2e362d901200a1075c3ca9c56d9c7bbef389" }, { "url": "https://git.kernel.org/stable/c/6837dd877270c57689bd866de9f3de14172c2439" }, { "url": "https://git.kernel.org/stable/c/1264971017b4d7141352a7fe29021bdfce5d885d" } ], "title": "net: drv: netdevsim: don't napi_complete() from netpoll", "x_generator": { "engine": "bippy-1.2.0" } } } }