CVE-2026-64034
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…
Does this matter?
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.
Description
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 mana_hwc_handle_resp() re-reads the same field from the same DMA buffer for test_bit() and pointer arithmetic. DMA-coherent memory is mapped uncacheable on x86 and is shared, unencrypted, in Confidential VMs (SEV-SNP/TDX), so each load goes directly to host-visible memory. A H/W can modify the value between the check and the use, bypassing the bounds validation. Fix this by reading hwc_msg_id exactly once using READ_ONCE() into a stack-local variable in mana_hwc_rx_event_handler(), and passing the validated value as a parameter to mana_hwc_handle_resp().
- CVSS 3.1
- 9.3 CRITICALCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
- EPSS
- 0.11% probability · 2th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-367
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS 0.1% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37Patch
- https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870Patch
- https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4Patch
- https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7Patch
- https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046efPatch
- https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cfPatch
- https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.