{"id":"CVE-2025-38270","state":"PUBLISHED","title":"net: drv: netdevsim: don't napi_complete() from netpoll","description":"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.","publishedAt":"2025-07-10T07:41:52.475Z","updatedAt":"2026-10-15T21:52:13.251Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"a8ff2e362d901200a1075c3ca9c56d9c7bbef389","versionType":"git"},{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"6837dd877270c57689bd866de9f3de14172c2439","versionType":"git"},{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"1264971017b4d7141352a7fe29021bdfce5d885d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/netdevsim/netdev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.34","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.3","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/netdevsim/netdev.c"]}],"references":["https://git.kernel.org/stable/c/a8ff2e362d901200a1075c3ca9c56d9c7bbef389","https://git.kernel.org/stable/c/6837dd877270c57689bd866de9f3de14172c2439","https://git.kernel.org/stable/c/1264971017b4d7141352a7fe29021bdfce5d885d"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/38xxx/CVE-2025-38270.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38270","state":"PUBLISHED","datePublished":"2025-07-10T07:41:52.475Z","dateUpdated":"2026-10-15T21:52:13.251Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:23.998Z"},"containers":{"cna":{"title":"net: drv: netdevsim: don't napi_complete() from netpoll","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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"a8ff2e362d901200a1075c3ca9c56d9c7bbef389","versionType":"git"},{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"6837dd877270c57689bd866de9f3de14172c2439","versionType":"git"},{"version":"3762ec05a9fbda16aaaa2568df679ab8ad13f38d","status":"affected","lessThan":"1264971017b4d7141352a7fe29021bdfce5d885d","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/netdevsim/netdev.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.10","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.10","versionType":"semver"},{"version":"6.12.34","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.3","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/net/netdevsim/netdev.c"]}],"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"}],"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."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:00:52.836Z"},"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"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2025-38270","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-15T21:49:13.510356Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-15T21:52:13.251Z"}}]}}}