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TI-2024-36949 Aliases CVE-2024-55881GHSA-h4p6-vxwp-4w5q

KVM: x86: Play nice with protected guests in complete_hypercall_exit()

Priority LOW 24Published · Updated

Key facts

Attack vector
Local
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
—
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 4 without a fix

Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.

Summary

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Play nice with protected guests in complete_hypercall_exit() Use is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit hypercall when completing said hypercall. For guests with protected state, e.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit mode as the vCPU state needed to detect 64-bit mode is unavailable. Hacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE hypercall via VMGEXIT trips the WARN: ------------[ cut here ]------------ WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm] Modules linked in: kvm_amd kvm ... [last unloaded: kvm] CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470 Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024 RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm] Call Trace: <TASK> kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm] kvm_vcpu_ioctl+0x54f/0x630 [kvm] __se_sys_ioctl+0x6b/0xc0 do_syscall_64+0x83/0x160 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> ---[ end trace 0000000000000000 ]---

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00209 11th percentileScored 2026-11-07
Fix Partial Linux (Linux): 5.15.176, 6.1.122, 6.6.68 +2Red Hat: 4 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
LinuxLinux5.15.5 to before 5.15.1765.15.176Patch availableCNA
LinuxLinux5.16 and later5.15.176, 6.1.122, 6.6.68, 6.12.7, 6.13Patch availableCNA
  • Linux VendorLinux Affected 5.15.5 to before 5.15.176 Fixed in 5.15.176 Patch available CNA
  • Linux VendorLinux Affected 5.16 and later Fixed in 5.15.176, 6.1.122, 6.6.68, 6.12.7, 6.13 Patch available CNA

CPE configurations NVD · 12

CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*5.15.5 to before 5.15.176; 5.16.1 to before 6.1.122; 6.2 to before 6.6.68; 6.7 to before 6.12.7VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:-:*:*:*:*:*:*5.16VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:*5.16 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:*5.16 rc3VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:*5.16 rc4VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:*5.16 rc5VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:*5.16 rc6VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc7:*:*:*:*:*:*5.16 rc7VulnerableLinux
cpe:2.3:o:linux:linux_kernel:5.16:rc8:*:*:*:*:*:*5.16 rc8VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:*6.13 rc1VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 5.15.5 to before 5.15.176; 5.16.1 to before 6.1.122; 6.2 to before 6.6.68; 6.7 to before 6.12.7 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:-:*:*:*:*:*:* Versions 5.16 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc2:*:*:*:*:*:* Versions 5.16 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc3:*:*:*:*:*:* Versions 5.16 rc3 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc4:*:*:*:*:*:* Versions 5.16 rc4 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc5:*:*:*:*:*:* Versions 5.16 rc5 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc6:*:*:*:*:*:* Versions 5.16 rc6 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc7:*:*:*:*:*:* Versions 5.16 rc7 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:5.16:rc8:*:*:*:*:*:* Versions 5.16 rc8 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* Versions 6.13 rc1 Vulnerable ·Linux
Show 2 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:*6.13 rc2VulnerableLinux
cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:*6.13 rc3VulnerableLinux
  • cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* Versions 6.13 rc2 Vulnerable ·Linux
  • cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* Versions 6.13 rc3 Vulnerable ·Linux

Remediation

  • Fix · CNA Linux (Linux) Fixed in 5.15.176
  • Fix · CNA Linux (Linux) Fixed in 5.15.176, 6.1.122, 6.6.68, 6.12.7, 6.13

Vendor assessments

Red Hat

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

ProductStatusPlan or fix
Red Hat Enterprise Linux 6AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 7AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 8AffectedNo fix planned: Out of support scope
Red Hat Enterprise Linux 9AffectedNo fix yet: Fix deferred

Timeline

  1. 2026-10-02 Threatist record created from CVE-2024-55881
  2. 2026-10-03 Alias added: GHSA-h4p6-vxwp-4w5q
  3. 2026-11-05 CISA SSVC decision points changed

References

Patch 5

  • 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