CVE-2026-64034 (GCVE-0-2026-64034)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-20 13:42
VLAI
Title
net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
Summary
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().
Severity
9.3 (Critical)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < a201c66edf2ebc6cfdc3813a889ba20fecebfae3 (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 70ad2dff8d052a85dfef15715b531f38a29108cf (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 566f42fb67a7ebfed6650e407e5b72e6b3e83bf7 (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 6180a06bbc99fd9114b8db4be6c4d46e40f046ef (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 09ec063d87c2dd3fa6f3561361a017bd882e9f37 (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 3c4db56ccd13dd020fbf43afabaee74a40ec75e4 (git)
Affected: ca9c54d2d6a5ab2430c4eda364c77125d62e5e0f , < 35f0f0a2536a4d604b4dbad92c85c4a8fdebb870 (git)
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Linux Linux Affected: 5.13
Unaffected: 0 , < 5.13 (semver)
Unaffected: 5.15.209 , ≤ 5.15.* (semver)
Unaffected: 6.1.175 , ≤ 6.1.* (semver)
Unaffected: 6.6.142 , ≤ 6.6.* (semver)
Unaffected: 6.12.92 , ≤ 6.12.* (semver)
Unaffected: 6.18.34 , ≤ 6.18.* (semver)
Unaffected: 7.0.11 , ≤ 7.0.* (semver)
Unaffected: 7.1 , ≤ * (original_commit_for_fix)
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  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

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Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.