{"id":"CVE-2024-55881","title":"KVM: x86: Play nice with protected guests in complete_hypercall_exit()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Play nice with protected guests in complete_hypercall_exit()\n\nUse is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit\nhypercall when completi…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 5969e2435cbd7f0ce8c28d717bfc39987ee8d8f1 < 0840d360a8909c722fb62459f42836afe32ededb","Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 7ed4db315094963de0678a8adfd43c46471b9349","Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 3d2634ec0d1dbe8f4b511cf5261f327c6a76f4b6","Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 22b5c2acd65dbe949032f619d4758a35a82fffc3","Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 9b42d1e8e4fe9dc631162c04caa69b0d1860b0f0","Linux >= 5.15.5 < 5.15.176","Linux 5.16"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-05T20:28:39.976365Z"},"published":"2025-01-11","updated":"2026-11-05","sourceUpdated":"2026-11-05T20:31:23.729Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2024-55881","references":[{"url":"https://git.kernel.org/stable/c/0840d360a8909c722fb62459f42836afe32ededb"},{"url":"https://git.kernel.org/stable/c/7ed4db315094963de0678a8adfd43c46471b9349"},{"url":"https://git.kernel.org/stable/c/3d2634ec0d1dbe8f4b511cf5261f327c6a76f4b6"},{"url":"https://git.kernel.org/stable/c/22b5c2acd65dbe949032f619d4758a35a82fffc3"},{"url":"https://git.kernel.org/stable/c/9b42d1e8e4fe9dc631162c04caa69b0d1860b0f0"}],"tags":["cve.org"],"epss":0.00209,"epssPercentile":0.11066,"ingestedAt":"2026-11-05T22:38:31.832Z","slug":"CVE-2024-55881","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nKVM: x86: Play nice with protected guests in complete_hypercall_exit()\n\nUse is_64_bit_hypercall() instead of is_64_bit_mode() to detect a 64-bit\nhypercall when completing said hypercall.  For guests with protected state,\ne.g. SEV-ES and SEV-SNP, KVM must assume the hypercall was made in 64-bit\nmode as the vCPU state needed to detect 64-bit mode is unavailable.\n\nHacking the sev_smoke_test selftest to generate a KVM_HC_MAP_GPA_RANGE\nhypercall via VMGEXIT trips the WARN:\n\n  ------------[ cut here ]------------\n  WARNING: CPU: 273 PID: 326626 at arch/x86/kvm/x86.h:180 complete_hypercall_exit+0x44/0xe0 [kvm]\n  Modules linked in: kvm_amd kvm ... [last unloaded: kvm]\n  CPU: 273 UID: 0 PID: 326626 Comm: sev_smoke_test Not tainted 6.12.0-smp--392e932fa0f3-feat #470\n  Hardware name: Google Astoria/astoria, BIOS 0.20240617.0-0 06/17/2024\n  RIP: 0010:complete_hypercall_exit+0x44/0xe0 [kvm]\n  Call Trace:\n   <TASK>\n   kvm_arch_vcpu_ioctl_run+0x2400/0x2720 [kvm]\n   kvm_vcpu_ioctl+0x54f/0x630 [kvm]\n   __se_sys_ioctl+0x6b/0xc0\n   do_syscall_64+0x83/0x160\n   entry_SYSCALL_64_after_hwframe+0x76/0x7e\n   </TASK>\n  ---[ end trace 0000000000000000 ]---\n\n## Affected\n\n- `Linux >= 5969e2435cbd7f0ce8c28d717bfc39987ee8d8f1 < 0840d360a8909c722fb62459f42836afe32ededb`\n- `Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 7ed4db315094963de0678a8adfd43c46471b9349`\n- `Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 3d2634ec0d1dbe8f4b511cf5261f327c6a76f4b6`\n- `Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 22b5c2acd65dbe949032f619d4758a35a82fffc3`\n- `Linux >= b5aead0064f33ae5e693a364e3204fe1c0ac9af2 < 9b42d1e8e4fe9dc631162c04caa69b0d1860b0f0`\n- `Linux >= 5.15.5 < 5.15.176`\n- `Linux 5.16`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}