{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-68330", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-30T09:28:09.383Z", "datePublished": "2026-08-10T12:03:06.542Z", "dateUpdated": "2026-08-17T05:03:28.769Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-17T05:03:28.769Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: airoha: Fix DMA direction for NPU mailbox buffer\n\nairoha_npu_send_msg() always maps the mailbox buffer with DMA_TO_DEVICE,\nbut some callers expect the NPU to write response data back into the\nsame buffer:\n\n- airoha_npu_wlan_msg_get() (NPU_OP_GET): NPU writes response into\n the buffer, then the caller reads it via memcpy()\n- airoha_npu_ppe_stats_setup() (NPU_OP_SET): NPU writes back\n npu_stats_addr field in the response\n\nOn non-cache-coherent architectures like EN7581 (Cortex-A53 without\nhardware cache coherency for NPU DMA), DMA_TO_DEVICE unmap is a no-op\n— it does not invalidate the CPU cache. If the NPU-written cache line\nis still present in the CPU cache when the caller reads the buffer,\nthe CPU observes stale data instead of the NPU response.\n\nThis is a timing-sensitive bug: small mailbox buffers (~24 bytes)\ntypically fit in a single cache line and may survive in the cache\nuntil the caller reads them, producing silent data corruption rather\nthan a crash. The bug is more likely to trigger when the caller reads\nthe response immediately after dma_unmap_single() without intervening\ncache-evicting operations.\n\nFix by using DMA_BIDIRECTIONAL for both map and unmap, which ensures\ndma_unmap_single() invalidates the CPU cache on non-coherent systems.\nThe mailbox buffers are small so there is no performance concern." } ], "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 defect is a host-side DMA-direction/cache-coherency error in the airoha NPU mailbox path; it is exercised through local driver probe, interface bring-up, and hardware flow-offload configuration, not by any remotely supplied packet data.\nAC:L - Each mailbox exchange on a non-coherent EN7581 SoC can return stale cache contents, and the affected setup paths can be re-entered repeatedly (offload teardown/re-setup, interface bring-up) while cache pressure is influenced by local activity, so the faulty read is reliably reproducible.\nPR:L - The vulnerable mailbox exchanges run during driver initialization and offload setup on these router SoCs; the lowest plausible trigger is an ordinary local user provoking interface/offload (re)initialization, and the probe-time instance requires no privileges at all.\nUI:N - No victim action is needed — the stale-response reads happen automatically during NPU/PPE/WLAN initialization and offload setup.\nS:U - The corrupted addresses and misdirected accesses stay within the kernel's own security authority on the affected SoC; no hypervisor or IOMMU security boundary is crossed by the defect itself.\nC:H - A stale npu_stats_addr causes devm_ioremap() of an unintended physical address whose contents are then read via memcpy_fromio() and exposed to userspace as flow-offload statistics, disclosing memory the driver was never meant to read.\nI:H - Stale responses are used as real addresses: memset_io() zeroes an unintended ioremapped region, and stale RXDESC_BASE values are written into WiFi ring descriptor base registers, causing device DMA writes into memory the driver does not own.\nA:H - Mapping and accessing a bogus physical address, and pointing hardware DMA rings at an invalid base, produce bus errors, descriptor-processing failures and memory corruption that lead to oops or system hang." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/net/ethernet/airoha/airoha_npu.c" ], "versions": [ { "version": "c52918744ee1e49cea86622a2633b9782446428f", "lessThan": "76fc5604308a109bf5838c2a0a0eb3ac6819f1ea", "status": "affected", "versionType": "git" }, { "version": "c52918744ee1e49cea86622a2633b9782446428f", "lessThan": "4c4d866a64f36718cbcdf20add372a599dd44311", "status": "affected", "versionType": "git" }, { "version": "c52918744ee1e49cea86622a2633b9782446428f", "lessThan": "6f884eb87a79e0c482baef2ad96c96b81d024235", "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/ethernet/airoha/airoha_npu.c" ], "versions": [ { "version": "6.16", "status": "affected" }, { "version": "0", "lessThan": "6.16", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.42", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.6", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "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": "6.16", "versionEndExcluding": "6.18.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.1.6" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.16", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/76fc5604308a109bf5838c2a0a0eb3ac6819f1ea" }, { "url": "https://git.kernel.org/stable/c/4c4d866a64f36718cbcdf20add372a599dd44311" }, { "url": "https://git.kernel.org/stable/c/6f884eb87a79e0c482baef2ad96c96b81d024235" } ], "title": "net: airoha: Fix DMA direction for NPU mailbox buffer", "x_generator": { "engine": "bippy-1.2.0" } } } }