net: mana: Fix TOCTOU double-fetch of hwc_msg_id from DMA buffer
Priority MEDIUM 41CWE-367Published · Updated
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 16 fixed, 1 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
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().
Why it matters now
Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00115 1st percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.209, 6.1.175, 6.6.142 +4Red Hat: 4 advisoriesRed Hat: 16 fixed, 1 without a fix
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 5.13 and later | 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 | Patch available | CNA |
- Linux VendorLinux Affected 5.13 and later Fixed in 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 5.13 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* | 7.1 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* | 7.1 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* | 7.1 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* | 7.1 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.13 to before 5.15.209; 5.16 to before 6.1.175; 6.2 to before 6.6.142; 6.7 to before 6.12.92; 6.13 to before 6.18.34; 6.19 to before 7.0.11 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc1:*:*:*:*:*:* Versions 7.1 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc2:*:*:*:*:*:* Versions 7.1 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc3:*:*:*:*:*:* Versions 7.1 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:7.1:rc4:*:*:*:*:*:* Versions 7.1 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.15.209, 6.1.175, 6.6.142, 6.12.92, 6.18.34, 7.0.11, 7.1
Red Hat 4 advisories
- RHSA-2026:75576 Released 2026-10-05 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- 10Base-SMTV kernel-modules-internal-6.12.0-211.62.1.el10_2
- Red Hat Enterprise Linux AppStream (v. 10) kernel-64k-debug-devel-6.12.0-211.62.1.el10_2, kernel-64k-debug-devel-matched-6.12.0-211.62.1.el10_2, kernel-64k-devel-6.12.0-211.62.1.el10_2 +12
- Red Hat Enterprise Linux BaseOS (v. 10) kernel-6.12.0-211.62.1.el10_2, kernel-64k-6.12.0-211.62.1.el10_2, kernel-64k-core-6.12.0-211.62.1.el10_2 +29
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) kernel-tools-libs-devel-6.12.0-211.62.1.el10_2, libperf-6.12.0-211.62.1.el10_2
- Red Hat Enterprise Linux Hidden (v. 10) kernel-modules-internal-6.12.0-211.62.1.el10_2
- Red Hat Enterprise Linux Real Time (v. 10) kernel-rt-6.12.0-211.62.1.el10_2, kernel-rt-64k-6.12.0-211.62.1.el10_2, kernel-rt-64k-core-6.12.0-211.62.1.el10_2 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 10) kernel-rt-6.12.0-211.62.1.el10_2, kernel-rt-core-6.12.0-211.62.1.el10_2, kernel-rt-debug-6.12.0-211.62.1.el10_2 +9
- RHSA-2026:72468 Released 2026-09-28 · Red Hat rating Importantkernel security update
- Red Hat Enterprise Linux BaseOS (v. 8) bpftool-4.18.0-553.169.1.el8_10, kernel-4.18.0-553.169.1.el8_10, kernel-abi-stablelists-4.18.0-553.169.1.el8_10 +19
- Red Hat Enterprise Linux CRB (v. 8) kernel-tools-libs-devel-4.18.0-553.169.1.el8_10
- RHSA-2026:72467 Released 2026-09-28 · Red Hat rating Importantkernel-rt security update
- Red Hat Enterprise Linux NFV (v. 8) kernel-rt-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-core-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-debug-4.18.0-553.169.1.rt7.510.el8_10 +9
- Red Hat Enterprise Linux RT (v. 8) kernel-rt-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-core-4.18.0-553.169.1.rt7.510.el8_10, kernel-rt-debug-4.18.0-553.169.1.rt7.510.el8_10 +7
Show 1 more Red Hat advisories
- RHSA-2026:66180 Released 2026-09-10 · Red Hat rating Importantkernel security, bug fix, and enhancement update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-687.46.1.el9_8, kernel-64k-debug-devel-matched-5.14.0-687.46.1.el9_8, kernel-64k-devel-5.14.0-687.46.1.el9_8 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-687.46.1.el9_8, kernel-64k-5.14.0-687.46.1.el9_8, kernel-64k-core-5.14.0-687.46.1.el9_8 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-687.46.1.el9_8, libperf-5.14.0-687.46.1.el9_8
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-64k-5.14.0-687.46.1.el9_8, kernel-rt-64k-core-5.14.0-687.46.1.el9_8 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-687.46.1.el9_8, kernel-rt-core-5.14.0-687.46.1.el9_8, kernel-rt-debug-5.14.0-687.46.1.el9_8 +9
Vendor assessments
Red Hat
Red Hat rating: Important. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 9 | Affected | No fix yet |
| 10Base-SMTV | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux AppStream (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux BaseOS (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux BaseOS (v. 8) | Fixed | RHSA-2026:72468 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux CRB (v. 8) | Fixed | RHSA-2026:72468 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Hidden (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux NFV (v. 8) | Fixed | RHSA-2026:72467 |
| Red Hat Enterprise Linux RT (v. 8) | Fixed | RHSA-2026:72467 |
| Red Hat Enterprise Linux Real Time (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2026:66180 |
| Red Hat Enterprise Linux Real Time for NFV (v. 10) | Fixed | RHSA-2026:75576 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2026:66180 |
Not affected: 2 products
- Red Hat Enterprise Linux 6
- Red Hat Enterprise Linux 7
Timeline
- 2026-10-02 Threatist record created from CVE-2026-64034
- 2026-10-03 Alias added: GHSA-r5hj-4chx-57cx
- 2026-10-05 Fix available: RHSA-2026:75576 · Red Hat
- 2026-10-05 Fix available: 10Base-SMTV, Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux BaseOS (v. 10) +4 · Red Hat
- 2026-10-13 Affected versions changed · Red Hat
- 2026-10-13 Weakness changed · NVD
- 2026-10-16 CISA SSVC decision points changed
- 2026-10-16 Priority changed: LOW → MEDIUM
- 2026-10-19 Weakness changed · CISA ADP
References
Patch 7
- https://git.kernel.org/stable/c/a201c66edf2ebc6cfdc3813a889ba20fecebfae3
- https://git.kernel.org/stable/c/70ad2dff8d052a85dfef15715b531f38a29108cf
- https://git.kernel.org/stable/c/566f42fb67a7ebfed6650e407e5b72e6b3e83bf7
- https://git.kernel.org/stable/c/6180a06bbc99fd9114b8db4be6c4d46e40f046ef
- https://git.kernel.org/stable/c/09ec063d87c2dd3fa6f3561361a017bd882e9f37
- https://git.kernel.org/stable/c/3c4db56ccd13dd020fbf43afabaee74a40ec75e4
- https://git.kernel.org/stable/c/35f0f0a2536a4d604b4dbad92c85c4a8fdebb870
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Sources
- CVE-2026-64034 · CVE Program
- CVE-2026-64034 · NVD
- FIRST EPSS
- GHSA-r5hj-4chx-57cx · GitHub Advisory Database · CC BY 4.0
- CVE-2026-64034 · Red Hat security data · CC BY 4.0
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