CVE-2025-40038
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: KVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid Skip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP isn't valid, e.g. because KVM is running with nrips=false. SVM must decode and emulate to skip the instruction if the CPU doesn't provide the next RIP, and getting the instruction bytes to decode requires reading guest memory. Reading guest memory through the emulator can fault, i.e. can sleep, which is disallowed since the fastpath handlers run with IRQs disabled. BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106 in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu preempt_count: 1, expected: 0 INFO: lockdep is turned off. irq event stamp: 30580 hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm] hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0 softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210 CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE Tainted: [U]=USER Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025 Call Trace: <TASK> dump_stack_lvl+0x7d/0xb0 __might_resched+0x271/0x290 __might_fault+0x28/0x80 kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm] kvm_fetch_guest_virt+0x92/0xc0 [kvm] __do_insn_fetch_bytes+0xf3/0x1e0 [kvm] x86_decode_insn+0xd1/0x1010 [kvm] x86_emulate_instruction+0x105/0x810 [kvm] __svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd] handle_fastpath_invd+0xc4/0x1a0 [kvm] vcpu_run+0x11a1/0x1db0 [kvm] kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm] kvm_vcpu_ioctl+0x578/0x6a0 [kvm] __se_sys_ioctl+0x6d/0xb0 do_syscall_64+0x8a/0x2c0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7f479d57a94b </TASK> Note, this is essentially a reapply of commit 5c30e8101e8d ("KVM: SVM: Skip WRMSR fastpath on VM-Exit if next RIP isn't valid"), but with different justification (KVM now grabs SRCU when skipping the instruction for other reasons).
View original CVE JSON
{
"id": "CVE-2025-40038",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2025-10-28T12:15:37.733",
"lastModified": "2026-10-19T21:10:00.160",
"vulnStatus": "Deferred",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Skip fastpath emulation on VM-Exit if next RIP isn't valid\n\nSkip the WRMSR and HLT fastpaths in SVM's VM-Exit handler if the next RIP\nisn't valid, e.g. because KVM is running with nrips=false. SVM must\ndecode and emulate to skip the instruction if the CPU doesn't provide the\nnext RIP, and getting the instruction bytes to decode requires reading\nguest memory. Reading guest memory through the emulator can fault, i.e.\ncan sleep, which is disallowed since the fastpath handlers run with IRQs\ndisabled.\n\n BUG: sleeping function called from invalid context at ./include/linux/uaccess.h:106\n in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu\n preempt_count: 1, expected: 0\n INFO: lockdep is turned off.\n irq event stamp: 30580\n hardirqs last enabled at (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm]\n hardirqs last disabled at (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0\n softirqs last enabled at (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210\n softirqs last disabled at (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210\n CPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE\n Tainted: [U]=USER\n Hardware name: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 01/17/2025\n Call Trace:\n <TASK>\n dump_stack_lvl+0x7d/0xb0\n __might_resched+0x271/0x290\n __might_fault+0x28/0x80\n kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm]\n kvm_fetch_guest_virt+0x92/0xc0 [kvm]\n __do_insn_fetch_bytes+0xf3/0x1e0 [kvm]\n x86_decode_insn+0xd1/0x1010 [kvm]\n x86_emulate_instruction+0x105/0x810 [kvm]\n __svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd]\n handle_fastpath_invd+0xc4/0x1a0 [kvm]\n vcpu_run+0x11a1/0x1db0 [kvm]\n kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm]\n kvm_vcpu_ioctl+0x578/0x6a0 [kvm]\n __se_sys_ioctl+0x6d/0xb0\n do_syscall_64+0x8a/0x2c0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f479d57a94b\n </TASK>\n\nNote, this is essentially a reapply of commit 5c30e8101e8d (\"KVM: SVM:\nSkip WRMSR fastpath on VM-Exit if next RIP isn't valid\"), but with\ndifferent justification (KVM now grabs SRCU when skipping the instruction\nfor other reasons)."
},
{
"lang": "es",
"value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nKVM: SVM: Omitir la emulación de ruta rápida en VM-Exit si el siguiente RIP no es válido\n\nOmitir las rutas rápidas de WRMSR y HLT en el gestor de VM-Exit de SVM si el siguiente RIP no es válido, p. ej., porque KVM se está ejecutando con nrips=false. SVM debe decodificar y emular para omitir la instrucción si la CPU no proporciona el siguiente RIP, y obtener los bytes de la instrucción para decodificar requiere leer la memoria invitada. La lectura de la memoria invitada a través del emulador puede fallar, es decir, puede entrar en suspensión, lo cual no está permitido ya que los gestores de ruta rápida se ejecutan con las IRQ deshabilitadas.\n\nBUG: función en suspensión llamada desde un contexto no válido en ./include/linux/uaccess.h:106\nin_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 32611, name: qemu\npreempt_count: 1, esperado: 0\nINFO: lockdep está desactivado.\nmarca de tiempo de evento irq: 30580\nhardirqs habilitadas por última vez en (30579): [<ffffffffc08b2527>] vcpu_run+0x1787/0x1db0 [kvm]\nhardirqs deshabilitadas por última vez en (30580): [<ffffffffb4f62e32>] __schedule+0x1e2/0xed0\nsoftirqs habilitadas por última vez en (30570): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210\nsoftirqs deshabilitadas por última vez en (30568): [<ffffffffb4247a64>] fpu_swap_kvm_fpstate+0x44/0x210\nCPU: 298 UID: 0 PID: 32611 Comm: qemu Tainted: G U 6.16.0-smp--e6c618b51cfe-sleep #782 NONE\nTainted: [U]=USER\nNombre del hardware: Google Astoria-Turin/astoria, BIOS 0.20241223.2-0 17/01/2025\nTraza de llamada:\n <TAREA>\n dump_stack_lvl+0x7d/0xb0\n __might_resched+0x271/0x290\n __might_fault+0x28/0x80\n kvm_vcpu_read_guest_page+0x8d/0xc0 [kvm]\n kvm_fetch_guest_virt+0x92/0xc0 [kvm]\n __do_insn_fetch_bytes+0xf3/0x1e0 [kvm]\n x86_decode_insn+0xd1/0x1010 [kvm]\n x86_emulate_instruction+0x105/0x810 [kvm]\n __svm_skip_emulated_instruction+0xc4/0x140 [kvm_amd]\n handle_fastpath_invd+0xc4/0x1a0 [kvm]\n vcpu_run+0x11a1/0x1db0 [kvm]\n kvm_arch_vcpu_ioctl_run+0x5cc/0x730 [kvm]\n kvm_vcpu_ioctl+0x578/0x6a0 [kvm]\n __se_sys_ioctl+0x6d/0xb0\n do_syscall_64+0x8a/0x2c0\n entry_SYSCALL_64_after_hwframe+0x4b/0x53\n RIP: 0033:0x7f479d57a94b\n </TAREA>\n\nTenga en cuenta que esto es esencialmente una reaplicación del commit 5c30e8101e8d ('KVM: SVM: Omitir la ruta rápida de WRMSR en VM-Exit si el siguiente RIP no es válido'), pero con una justificación diferente (KVM ahora toma SRCU al omitir la instrucción por otras razones)."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"arch/x86/kvm/svm/svm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "b439eb8ab578557263815ba8581d02c1b730e348",
"lessThan": "cd3efb93677c4b0cf76348882fb429165fee33fd",
"versionType": "git",
"status": "affected"
},
{
"version": "b439eb8ab578557263815ba8581d02c1b730e348",
"lessThan": "f994e9c790ce97d3cf01af4d0a1b9add0c955aee",
"versionType": "git",
"status": "affected"
},
{
"version": "b439eb8ab578557263815ba8581d02c1b730e348",
"lessThan": "da2a3c231f7f2a5ac146d972b8c1d7d84aff6d70",
"versionType": "git",
"status": "affected"
},
{
"version": "b439eb8ab578557263815ba8581d02c1b730e348",
"lessThan": "0910dd7c9ad45a2605c45fd2bf3d1bcac087687c",
"versionType": "git",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"arch/x86/kvm/svm/svm.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "6.5",
"status": "affected"
},
{
"version": "0",
"lessThan": "6.5",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.113",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.53",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.17.3",
"lessThanOrEqual": "6.17.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H",
"baseScore": 7.1,
"baseSeverity": "HIGH",
"attackVector": "LOCAL",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "CHANGED",
"confidentialityImpact": "NONE",
"integrityImpact": "NONE",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 2.5,
"impactScore": 4.0
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-15T21:56:18.073513Z",
"id": "CVE-2025-40038",
"options": [
{
"exploitation": "none"
},
{
"automatable": "no"
},
{
"technicalImpact": "partial"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"references": [
{
"url": "https://git.kernel.org/stable/c/0910dd7c9ad45a2605c45fd2bf3d1bcac087687c",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/cd3efb93677c4b0cf76348882fb429165fee33fd",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/da2a3c231f7f2a5ac146d972b8c1d7d84aff6d70",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f994e9c790ce97d3cf01af4d0a1b9add0c955aee",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
]
}