{"cve":"CVE-2026-68330","nvd":{"published":"2026-08-10T13:20:23.293","modified":"2026-08-17T06:17:41.097","status":"Received","description":"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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","score":7.8},"cwes":[],"references":["https://git.kernel.org/stable/c/4c4d866a64f36718cbcdf20add372a599dd44311","https://git.kernel.org/stable/c/6f884eb87a79e0c482baef2ad96c96b81d024235","https://git.kernel.org/stable/c/76fc5604308a109bf5838c2a0a0eb3ac6819f1ea"],"products":[],"source":"nvd","synced_at":"2026-10-19T22:47:54.990491175+00:00"},"epss":{"cve":"CVE-2026-68330","score":0.00162,"percentile":0.05329,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}