CVE-2026-64457
In the Linux kernel, the following vulnerability has been resolved:
virtio_pci: fix vq info pointer lookup via wrong index
Unbinding a virtio balloon device:
triggers a NULL pointer dereference. The dmesg says:
The virtio_balloon device registers 5 queues (inflate, deflate, stats, free_page, reporting) but only the first two are unconditional. The stats, free_page and reporting queues are each conditional on their respective feature bits. When any of these features are absent, the corresponding vqs_info entry has name == NULL, creating holes in the array.
The root cause is an indexing mismatch introduced when vq info storage was changed to be passed as an argument. vp_find_vqs_msix() and vp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i' is the caller's sparse array index.
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However, the virtqueue itself gets vq->index assigned from queue_idx, a dense index that skips NULL entries. When holes exist, 'i' and queue_idx diverge. Later, vp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense index into the sparsely-populated array, and hits NULL.
Fix this by storing info at vp_dev->vqs[queue_idx] instead of vp_dev->vqs[i], so the store index matches the lookup index (vq->index). Apply the fix to both the MSIX and INTX paths.
Detalles técnicos trazas, registros y código del informe original
echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind
BUG: kernel NULL pointer dereference, address: 0000000000000008
[...]
RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0
Call Trace:
<TASK>
vp_del_vqs+0x121/0x230
remove_common+0x135/0x150
virtballoon_remove+0xee/0x100
virtio_dev_remove+0x3b/0x80
device_release_driver_internal+0x187/0x2c0
unbind_store+0xb9/0xe0
kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180
vfs_write+0x2a9/0x3b0
ksys_write+0x5c/0xd0
do_syscall_64+0x54/0x230
entry_SYSCALL_64_after_hwframe+0x29/0x31
[...]
</TASK>CVSS
NVD no ha asignado puntuación CVSS a esta CVE (habitual desde el cambio de política de abril de 2026).
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.21%
- Percentil entre todas las CVEs puntuadas: 10
- 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)
⚠ Inferidas por IA a partir de la descripción — NVD aún no ha analizado esta CVE; no son CPE verificados.
Referencias
JSON original (NVD)
Mostrar
{
"id": "CVE-2026-64457",
"cveTags": [],
"metrics": {},
"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": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"lessThan": "41e6dc1a10036c9f47057033f19af7e52ec464b6",
"versionType": "git"
},
{
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"lessThan": "075bc3c779e1ea7294afabdcb7e0a49536959b28",
"versionType": "git"
},
{
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"lessThan": "64a4c0befa77bcc01076aec9f93863ffd4ed06b7",
"versionType": "git"
},
{
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"lessThan": "f7d380fb525c13bdd114369a1979c80c346e6abc",
"versionType": "git"
}
],
"programFiles": [
"drivers/virtio/virtio_pci_common.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/virtio/virtio_pci_common.c"
],
"defaultStatus": "affected"
}
]
}
],
"published": "2026-07-25T10:17:30.830",
"references": [
{
"url": "https://git.kernel.org/stable/c/075bc3c779e1ea7294afabdcb7e0a49536959b28",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/41e6dc1a10036c9f47057033f19af7e52ec464b6",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/64a4c0befa77bcc01076aec9f93863ffd4ed06b7",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
},
{
"url": "https://git.kernel.org/stable/c/f7d380fb525c13bdd114369a1979c80c346e6abc",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"vulnStatus": "Received",
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirtio_pci: fix vq info pointer lookup via wrong index\n\nUnbinding a virtio balloon device:\n\n echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind\n\ntriggers a NULL pointer dereference. The dmesg says:\n\n BUG: kernel NULL pointer dereference, address: 0000000000000008\n [...]\n RIP: 0010:__list_del_entry_valid_or_report+0x5/0xf0\n Call Trace:\n <TASK>\n vp_del_vqs+0x121/0x230\n remove_common+0x135/0x150\n virtballoon_remove+0xee/0x100\n virtio_dev_remove+0x3b/0x80\n device_release_driver_internal+0x187/0x2c0\n unbind_store+0xb9/0xe0\n kernfs_fop_write_iter.llvm.11660790530567441834+0xf6/0x180\n vfs_write+0x2a9/0x3b0\n ksys_write+0x5c/0xd0\n do_syscall_64+0x54/0x230\n entry_SYSCALL_64_after_hwframe+0x29/0x31\n [...]\n </TASK>\n\nThe virtio_balloon device registers 5 queues (inflate, deflate, stats,\nfree_page, reporting) but only the first two are unconditional. The\nstats, free_page and reporting queues are each conditional on their\nrespective feature bits. When any of these features are absent, the\ncorresponding vqs_info entry has name == NULL, creating holes in the\narray.\n\nThe root cause is an indexing mismatch introduced when vq info storage\nwas changed to be passed as an argument. vp_find_vqs_msix() and\nvp_find_vqs_intx() store the info pointer at vp_dev->vqs[i], where 'i'\nis the caller's sparse array index. However, the virtqueue itself gets\nvq->index assigned from queue_idx, a dense index that skips NULL\nentries. When holes exist, 'i' and queue_idx diverge. Later,\nvp_del_vqs() looks up info via vp_dev->vqs[vq->index] using the dense\nindex into the sparsely-populated array, and hits NULL.\n\nFix this by storing info at vp_dev->vqs[queue_idx] instead of\nvp_dev->vqs[i], so the store index matches the lookup index\n(vq->index). Apply the fix to both the MSIX and INTX paths."
}
],
"lastModified": "2026-08-17T05:17:50.867",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}