{"id":"CVE-2026-64034","summary":"net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer","details":"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-\u003eresponse.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().","modified":"2026-07-22T05:30:06.714797904Z","published":"2026-07-19T15:39:23.470Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64034.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37"},{"type":"WEB","url":"https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef"},{"type":"WEB","url":"https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64034.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64034"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f"},{"fixed":"a201c66edf2ebc6cfdc3813a889ba20fecebfae3"},{"fixed":"70ad2dff8d052a85dfef15715b531f38a29108cf"},{"fixed":"566f42fb67a7ebfed6650e407e5b72e6b3e83bf7"},{"fixed":"6180a06bbc99fd9114b8db4be6c4d46e40f046ef"},{"fixed":"09ec063d87c2dd3fa6f3561361a017bd882e9f37"},{"fixed":"3c4db56ccd13dd020fbf43afabaee74a40ec75e4"},{"fixed":"35f0f0a2536a4d604b4dbad92c85c4a8fdebb870"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64034.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"5.13.0"},{"fixed":"5.15.209"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.175"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.142"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.92"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64034.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}]}