CVE-2026-64457 (GCVE-0-2026-64457)
Vulnerability from cvelistv5
Published
2026-07-25 08:51
Modified
2026-08-17 04:56
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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:
echo virtio0 > /sys/bus/virtio/drivers/virtio_balloon/unbind
triggers a NULL pointer dereference. The dmesg says:
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>
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. 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.
References
| URL | Tags | |
|---|---|---|
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/virtio/virtio_pci_common.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "41e6dc1a10036c9f47057033f19af7e52ec464b6",
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"versionType": "git"
},
{
"lessThan": "075bc3c779e1ea7294afabdcb7e0a49536959b28",
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"versionType": "git"
},
{
"lessThan": "64a4c0befa77bcc01076aec9f93863ffd4ed06b7",
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"versionType": "git"
},
{
"lessThan": "f7d380fb525c13bdd114369a1979c80c346e6abc",
"status": "affected",
"version": "89a1c435aec269d109ed46ca7bbb10fa8edf7ace",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/virtio/virtio_pci_common.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.11"
},
{
"lessThan": "6.11",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.96",
"versionStartIncluding": "6.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.39",
"versionStartIncluding": "6.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.4",
"versionStartIncluding": "6.11",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.11",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"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 \u003e /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 \u003cTASK\u003e\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 \u003c/TASK\u003e\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-\u003evqs[i], where \u0027i\u0027\nis the caller\u0027s sparse array index. However, the virtqueue itself gets\nvq-\u003eindex assigned from queue_idx, a dense index that skips NULL\nentries. When holes exist, \u0027i\u0027 and queue_idx diverge. Later,\nvp_del_vqs() looks up info via vp_dev-\u003evqs[vq-\u003eindex] using the dense\nindex into the sparsely-populated array, and hits NULL.\n\nFix this by storing info at vp_dev-\u003evqs[queue_idx] instead of\nvp_dev-\u003evqs[i], so the store index matches the lookup index\n(vq-\u003eindex). Apply the fix to both the MSIX and INTX paths."
}
],
"providerMetadata": {
"dateUpdated": "2026-08-17T04:56:01.747Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/41e6dc1a10036c9f47057033f19af7e52ec464b6"
},
{
"url": "https://git.kernel.org/stable/c/075bc3c779e1ea7294afabdcb7e0a49536959b28"
},
{
"url": "https://git.kernel.org/stable/c/64a4c0befa77bcc01076aec9f93863ffd4ed06b7"
},
{
"url": "https://git.kernel.org/stable/c/f7d380fb525c13bdd114369a1979c80c346e6abc"
}
],
"title": "virtio_pci: fix vq info pointer lookup via wrong index",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-64457",
"datePublished": "2026-07-25T08:51:25.364Z",
"dateReserved": "2026-07-19T15:36:31.789Z",
"dateUpdated": "2026-08-17T04:56:01.747Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Loading…
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
Loading…
Loading…