{"id":"CVE-2026-64034","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64034","generatedAt":"2026-10-28T02:18:48.782Z","title":"In the Linux kernel, the following vulnerability has been resolved: net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer In mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from DMA-coherent memory and bounds-checked, then…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer\n\nIn mana_hwc_rx_event_handler(), resp->response.hwc_msg_id is read from\nDMA-coherent memory and bounds-checked, then mana_hwc_handle_resp()\nre-reads the same field from the same DMA buffer for test_bit() and\npointer arithmetic.\n\nDMA-coherent memory is mapped uncacheable on x86 and is shared,\nunencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes\ndirectly to host-visible memory. A H/W can modify the value\nbetween the check and the use, bypassing the bounds validation.\n\nFix this by reading hwc_msg_id exactly once using READ_ONCE() into a\nstack-local variable in mana_hwc_rx_event_handler(), and passing the\nvalidated value as a parameter to mana_hwc_handle_resp().","published":"2026-07-19T16:17:44.000Z","lastModified":"2026-10-19T21:17:21.000Z","status":"Modified","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":{"version":"3.1","score":9.3,"severity":"CRITICAL","vector":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"},"cwe":["CWE-367"],"affected":["linux/linux kernel"],"epss":{"score":0.00115,"percentile":0.01556,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.11%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3","tags":["Patch"],"source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64034","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}