CVE-2026-64034net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
- 9.3CriticalCVSS base score
- 0.11%Exploitation in 30 daysEPSS · top 98% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- NonePublic exploitsnone known yet
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().
Timeline
ID reserved
By Linux
Published
- 3 months later
· 3 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| LinuxCNA (assigner) | 3.1 | Critical9.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
| NVDNVD · Modified | 3.1 | Critical9.3 | CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 0.11% · top 98% of all CVEs (14 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: total
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.3.
Affected products
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < a201c66edf2ebc6cfdc3813a889ba20fecebfae3
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 70ad2dff8d052a85dfef15715b531f38a29108cf
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 566f42fb67a7ebfed6650e407e5b72e6b3e83bf7
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 6180a06bbc99fd9114b8db4be6c4d46e40f046ef
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 09ec063d87c2dd3fa6f3561361a017bd882e9f37
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 3c4db56ccd13dd020fbf43afabaee74a40ec75e4
- affected ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f – < 35f0f0a2536a4d604b4dbad92c85c4a8fdebb870
- affected 5.13
- unaffected < 5.13
- unaffected 5.15.209 – ≤ 5.15.*
- unaffected 6.1.175 – ≤ 6.1.*
- unaffected 6.6.142 – ≤ 6.6.*
- unaffected 6.12.92 – ≤ 6.12.*
- unaffected 6.18.34 – ≤ 6.18.*
- unaffected 7.0.11 – ≤ 7.0.*
- unaffected 7.1 – ≤ *
References
References7
- https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3 (opens in a new tab)
- https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf (opens in a new tab)
- https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7 (opens in a new tab)
- https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef (opens in a new tab)
- https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37 (opens in a new tab)
- https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4 (opens in a new tab)
- https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2026-45607 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2026-64034)Record last updated .