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TI-2024-23740 Aliases CVE-2024-35875GHSA-43j5-9vgx-7g7j

x86/coco: Require seeding RNG with RDRAND on CoCo systems

Priority LOW 36Published · 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: 10 fixed, 2 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: x86/coco: Require seeding RNG with RDRAND on CoCo systems There are few uses of CoCo that don't rely on working cryptography and hence a working RNG. Unfortunately, the CoCo threat model means that the VM host cannot be trusted and may actively work against guests to extract secrets or manipulate computation. Since a malicious host can modify or observe nearly all inputs to guests, the only remaining source of entropy for CoCo guests is RDRAND. If RDRAND is broken -- due to CPU hardware fault -- the RNG as a whole is meant to gracefully continue on gathering entropy from other sources, but since there aren't other sources on CoCo, this is catastrophic. This is mostly a concern at boot time when initially seeding the RNG, as after that the consequences of a broken RDRAND are much more theoretical. So, try at boot to seed the RNG using 256 bits of RDRAND output. If this fails, panic(). This will also trigger if the system is booted without RDRAND, as RDRAND is essential for a safe CoCo boot. Add this deliberately to be "just a CoCo x86 driver feature" and not part of the RNG itself. Many device drivers and platforms have some desire to contribute something to the RNG, and add_device_randomness() is specifically meant for this purpose. Any driver can call it with seed data of any quality, or even garbage quality, and it can only possibly make the quality of the RNG better or have no effect, but can never make it worse. Rather than trying to build something into the core of the RNG, consider the particular CoCo issue just a CoCo issue, and therefore separate it all out into driver (well, arch/platform) code. [ bp: Massage commit message. ]

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00252 16th percentileScored 2026-11-07
Fix Partial Linux (Linux): 6.1.85, 6.6.26, 6.8.5 +1Red Hat: 3 advisoriesRed Hat: 10 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
LinuxLinux4.15 and later6.1.85, 6.6.26, 6.8.5, 6.9Patch availableCNA
  • Linux VendorLinux Affected 4.15 and later Fixed in 6.1.85, 6.6.26, 6.8.5, 6.9 Patch available CNA

CPE configurations NVD · 3

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*before 6.1.85; 6.2 to before 6.6.26; 6.7 to before 6.8.5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:*6.9 rc1VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:*6.9 rc2VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 6.1.85; 6.2 to before 6.6.26; 6.7 to before 6.8.5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.9:rc1:*:*:*:*:*:* Versions 6.9 rc1 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.9:rc2:*:*:*:*:*:* Versions 6.9 rc2 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 6.1.85, 6.6.26, 6.8.5, 6.9

Red Hat 3 advisories

  • RHSA-2024:6567 Released 2024-09-11 · Red Hat rating Moderate
    kernel security update
    • Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-427.35.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.35.1.el9_4, kernel-64k-devel-5.14.0-427.35.1.el9_4 +11
    • Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.3.0-427.35.1.el9_4, kernel-5.14.0-427.35.1.el9_4, kernel-64k-5.14.0-427.35.1.el9_4 +29
    • Red Hat Enterprise Linux CRB (v. 9) kernel-tools-libs-devel-5.14.0-427.35.1.el9_4, libperf-5.14.0-427.35.1.el9_4
    • Red Hat Enterprise Linux NFV (v. 9) kernel-rt-5.14.0-427.35.1.el9_4, kernel-rt-core-5.14.0-427.35.1.el9_4, kernel-rt-debug-5.14.0-427.35.1.el9_4 +11
    • Red Hat Enterprise Linux RT (v. 9) kernel-rt-5.14.0-427.35.1.el9_4, kernel-rt-core-5.14.0-427.35.1.el9_4, kernel-rt-debug-5.14.0-427.35.1.el9_4 +9
  • RHSA-2024:6267 Released 2024-09-04 · Red Hat rating Moderate
    kernel security update
    • Red Hat CodeReady Linux Builder EUS (v.9.2) kernel-tools-libs-devel-5.14.0-284.82.1.el9_2
    • Red Hat Enterprise Linux AppStream EUS (v.9.2) kernel-64k-debug-devel-5.14.0-284.82.1.el9_2, kernel-64k-debug-devel-matched-5.14.0-284.82.1.el9_2, kernel-64k-devel-5.14.0-284.82.1.el9_2 +9
    • Red Hat Enterprise Linux BaseOS EUS (v.9.2) bpftool-7.0.0-284.82.1.el9_2, kernel-5.14.0-284.82.1.el9_2, kernel-64k-5.14.0-284.82.1.el9_2 +29
  • RHSA-2024:6268 Released 2024-09-04 · Red Hat rating Moderate
    kernel-rt security update
    • Red Hat Enterprise Linux Real Time EUS (v.9.2) kernel-rt-5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-core-5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-5.14.0-284.82.1.rt14.367.el9_2 +9
    • Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2) kernel-rt-5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-core-5.14.0-284.82.1.rt14.367.el9_2, kernel-rt-debug-5.14.0-284.82.1.rt14.367.el9_2 +11

Vendor assessments

Red Hat

Red Hat rating: Moderate. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat Enterprise Linux 8AffectedNo fix planned: Will not fix
Red Hat Enterprise Linux 9AffectedNo fix yet
Red Hat CodeReady Linux Builder EUS (v.9.2)Fixed RHSA-2024:6267
Red Hat Enterprise Linux AppStream (v. 9)Fixed RHSA-2024:6567
Red Hat Enterprise Linux AppStream EUS (v.9.2)Fixed RHSA-2024:6267
Red Hat Enterprise Linux BaseOS (v. 9)Fixed RHSA-2024:6567
Red Hat Enterprise Linux BaseOS EUS (v.9.2)Fixed RHSA-2024:6267
Red Hat Enterprise Linux CRB (v. 9)Fixed RHSA-2024:6567
Red Hat Enterprise Linux NFV (v. 9)Fixed RHSA-2024:6567
Red Hat Enterprise Linux RT (v. 9)Fixed RHSA-2024:6567
Red Hat Enterprise Linux Real Time EUS (v.9.2)Fixed RHSA-2024:6268
Red Hat Enterprise Linux Real Time for NFV EUS (v.9.2)Fixed RHSA-2024:6268
Not affected: 3 products
  • Red Hat Enterprise Linux 6
  • Red Hat Enterprise Linux 7
  • Red Hat Enterprise Linux AppStream EUS (v.9.2)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-35875
  2. 2026-10-03 Alias added: GHSA-43j5-9vgx-7g7j

References

Patch 4

  • TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
  • TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
  • TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
  • TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
  • TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
  • TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
See all 15278 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences