CVE-2026-31592
Estado: AnalizadaMedia (5.5)—
In the Linux kernel, the following vulnerability has been resolved:
KVM: SEV: Protect *all* of sev_mem_enc_register_region() with kvm->lock
Take and hold kvm->lock for before checking sev_guest() in sev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock is held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't rollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to a not-yet-initialized sev->regions_list, e.g. triggering a #GP
with a syzlang reproducer that looks like:
Opportunistically use guard() to avoid having to define a new error label and goto usage.
Detalles técnicos trazas, registros y código del informe original
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE
Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE
Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024
RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83
Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00
RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256
RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000
RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000
RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000
R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000
R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000
FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0
Call Trace:
<TASK>
kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371
kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363
__se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51
do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x76/0x7e
RIP: 0033:0x7f34e9f7e9a9
Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9
RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007
RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8
</TASK>
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)
syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB="..."], 0x4f}) (async)
r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)
r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)
r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)
r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)
ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)
ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)
ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)
r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)
openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)
ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)
r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)
close(r0) (async)
openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)
ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)
ioctl$KVM_RUN(r5, 0xae80, 0x0)CVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- Puntuación base: 5.5
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.16%
- Percentil entre todas las CVEs puntuadas: 5
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
Tecnologías afectadas (1)
CWE
- CWE-476
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-31592",
"cveTags": [],
"metrics": {
"cvssMetricV31": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"cvssData": {
"scope": "UNCHANGED",
"version": "3.1",
"baseScore": 5.5,
"attackVector": "LOCAL",
"baseSeverity": "MEDIUM",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
"integrityImpact": "NONE",
"userInteraction": "NONE",
"attackComplexity": "LOW",
"availabilityImpact": "HIGH",
"privilegesRequired": "LOW",
"confidentialityImpact": "NONE"
},
"impactScore": 3.6,
"exploitabilityScore": 1.8
}
]
},
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1e80fdc09d121d8327cdf62eefbb5abadddca792",
"lessThan": "35a0963d361f98bba798fd15d229dcb166c04684",
"versionType": "git"
},
{
"status": "affected",
"version": "1e80fdc09d121d8327cdf62eefbb5abadddca792",
"lessThan": "ab725ac3022469ecd4d7aa7d5646712e98b249d8",
"versionType": "git"
},
{
"status": "affected",
"version": "1e80fdc09d121d8327cdf62eefbb5abadddca792",
"lessThan": "0ff93ff0ba82e9511770e175fa50682a1ab14fb6",
"versionType": "git"
},
{
"status": "affected",
"version": "1e80fdc09d121d8327cdf62eefbb5abadddca792",
"lessThan": "b6408b6cec5df76a165575777800ef2aba12b109",
"versionType": "git"
}
],
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.16"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.16",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.18.24",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.14",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0.1",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"arch/x86/kvm/svm/sev.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-04-24T15:16:36.667",
"references": [
{
"url": "https://git.kernel.org/stable/c/0ff93ff0ba82e9511770e175fa50682a1ab14fb6",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/35a0963d361f98bba798fd15d229dcb166c04684",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/ab725ac3022469ecd4d7aa7d5646712e98b249d8",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/b6408b6cec5df76a165575777800ef2aba12b109",
"tags": [
"Patch"
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Analyzed",
"weaknesses": [
{
"type": "Primary",
"source": "nvd@nist.gov",
"description": [
{
"lang": "en",
"value": "CWE-476"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Protect *all* of sev_mem_enc_register_region() with kvm->lock\n\nTake and hold kvm->lock for before checking sev_guest() in\nsev_mem_enc_register_region(), as sev_guest() isn't stable unless kvm->lock\nis held (or KVM can guarantee KVM_SEV_INIT{2} has completed and can't\nrollack state). If KVM_SEV_INIT{2} fails, KVM can end up trying to add to\na not-yet-initialized sev->regions_list, e.g. triggering a #GP\n\n Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI\n KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]\n CPU: 110 UID: 0 PID: 72717 Comm: syz.15.11462 Tainted: G U W O 6.16.0-smp-DEV #1 NONE\n Tainted: [U]=USER, [W]=WARN, [O]=OOT_MODULE\n Hardware name: Google, Inc. Arcadia_IT_80/Arcadia_IT_80, BIOS 12.52.0-0 10/28/2024\n RIP: 0010:sev_mem_enc_register_region+0x3f0/0x4f0 ../include/linux/list.h:83\n Code: <41> 80 3c 04 00 74 08 4c 89 ff e8 f1 c7 a2 00 49 39 ed 0f 84 c6 00\n RSP: 0018:ffff88838647fbb8 EFLAGS: 00010256\n RAX: dffffc0000000000 RBX: 1ffff92015cf1e0b RCX: dffffc0000000000\n RDX: 0000000000000000 RSI: 0000000000001000 RDI: ffff888367870000\n RBP: ffffc900ae78f050 R08: ffffea000d9e0007 R09: 1ffffd4001b3c000\n R10: dffffc0000000000 R11: fffff94001b3c001 R12: 0000000000000000\n R13: ffff8982ab0bde00 R14: ffffc900ae78f058 R15: 0000000000000000\n FS: 00007f34e9dc66c0(0000) GS:ffff89ee64d33000(0000) knlGS:0000000000000000\n CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033\n CR2: 00007fe180adef98 CR3: 000000047210e000 CR4: 0000000000350ef0\n Call Trace:\n <TASK>\n kvm_arch_vm_ioctl+0xa72/0x1240 ../arch/x86/kvm/x86.c:7371\n kvm_vm_ioctl+0x649/0x990 ../virt/kvm/kvm_main.c:5363\n __se_sys_ioctl+0x101/0x170 ../fs/ioctl.c:51\n do_syscall_x64 ../arch/x86/entry/syscall_64.c:63 [inline]\n do_syscall_64+0x6f/0x1f0 ../arch/x86/entry/syscall_64.c:94\n entry_SYSCALL_64_after_hwframe+0x76/0x7e\n RIP: 0033:0x7f34e9f7e9a9\n Code: <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48\n RSP: 002b:00007f34e9dc6038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010\n RAX: ffffffffffffffda RBX: 00007f34ea1a6080 RCX: 00007f34e9f7e9a9\n RDX: 0000200000000280 RSI: 000000008010aebb RDI: 0000000000000007\n RBP: 00007f34ea000d69 R08: 0000000000000000 R09: 0000000000000000\n R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000\n R13: 0000000000000000 R14: 00007f34ea1a6080 R15: 00007ffce77197a8\n </TASK>\n\nwith a syzlang reproducer that looks like:\n\n syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000040)={0x0, &(0x7f0000000180)=ANY=[], 0x70}) (async)\n syz_kvm_add_vcpu$x86(0x0, &(0x7f0000000080)={0x0, &(0x7f0000000180)=ANY=[@ANYBLOB=\"...\"], 0x4f}) (async)\n r0 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000200), 0x0, 0x0)\n r1 = ioctl$KVM_CREATE_VM(r0, 0xae01, 0x0)\n r2 = openat$kvm(0xffffffffffffff9c, &(0x7f0000000240), 0x0, 0x0)\n r3 = ioctl$KVM_CREATE_VM(r2, 0xae01, 0x0)\n ioctl$KVM_SET_CLOCK(r3, 0xc008aeba, &(0x7f0000000040)={0x1, 0x8, 0x0, 0x5625e9b0}) (async)\n ioctl$KVM_SET_PIT2(r3, 0x8010aebb, &(0x7f0000000280)={[...], 0x5}) (async)\n ioctl$KVM_SET_PIT2(r1, 0x4070aea0, 0x0) (async)\n r4 = ioctl$KVM_CREATE_VM(0xffffffffffffffff, 0xae01, 0x0)\n openat$kvm(0xffffffffffffff9c, 0x0, 0x0, 0x0) (async)\n ioctl$KVM_SET_USER_MEMORY_REGION(r4, 0x4020ae46, &(0x7f0000000400)={0x0, 0x0, 0x0, 0x2000, &(0x7f0000001000/0x2000)=nil}) (async)\n r5 = ioctl$KVM_CREATE_VCPU(r4, 0xae41, 0x2)\n close(r0) (async)\n openat$kvm(0xffffffffffffff9c, &(0x7f0000000000), 0x8000, 0x0) (async)\n ioctl$KVM_SET_GUEST_DEBUG(r5, 0x4048ae9b, &(0x7f0000000300)={0x4376ea830d46549b, 0x0, [0x46, 0x0, 0x0, 0x0, 0x0, 0x1000]}) (async)\n ioctl$KVM_RUN(r5, 0xae80, 0x0)\n\nOpportunistically use guard() to avoid having to define a new error label\nand goto usage."
}
],
"lastModified": "2026-06-17T10:34:02.770",
"configurations": [
{
"nodes": [
{
"negate": false,
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "4B2F764F-84E7-49EF-8E7A-C811DB6A0345",
"versionEndExcluding": "6.18.24",
"versionStartIncluding": "4.16"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "D6A8A074-BBF4-4803-ABED-519A839435BB",
"versionEndExcluding": "6.19.14",
"versionStartIncluding": "6.19"
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"vulnerable": true,
"matchCriteriaId": "9B5888AB-7403-4335-89E4-21CC0B48366A",
"versionEndExcluding": "7.0.1",
"versionStartIncluding": "7.0"
}
],
"operator": "OR"
}
]
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}