Action not permitted
Modal body text goes here.
Modal Title
Modal Body
EUVD-2026-369406
European Vulnerability Database identifier assigned by ENISAReserved
2026-10-02 08:37
Assigner
ENISA
Alias of
a CVE record, shown under related vulnerabilities.
This identifier carries no description, severity or references of its own:
they belong to that CVE.
{
"assigner": "ENISA",
"date_reserved": "2026-10-02T08:37:17.859833+00:00",
"id": "EUVD-2026-369406"
}
CVE-2026-89777 (GCVE-0-2026-89777)
Vulnerability from cvelistv5 – Published: 2026-09-16 08:48 – Updated: 2026-09-16 14:38
VLAI
EPSS
VEX
Title
vfio/pci: clear vdev->msi_perm after freeing it on init failure
Summary
In the Linux kernel, the following vulnerability has been resolved:
vfio/pci: clear vdev->msi_perm after freeing it on init failure
vfio_msi_cap_len() lazily allocates the per-device MSI permission table:
vdev->msi_perm = kmalloc_obj(struct perm_bits, GFP_KERNEL_ACCOUNT);
if (!vdev->msi_perm)
return -ENOMEM;
ret = init_pci_cap_msi_perm(vdev->msi_perm, len, flags);
if (ret) {
kfree(vdev->msi_perm);
return ret; /* vdev->msi_perm left dangling */
}
When init_pci_cap_msi_perm() -> alloc_perm_bits() fails with -ENOMEM, the
error path frees vdev->msi_perm but leaves the freed pointer stored in
it. vdev->msi_perm is not re-zeroed later because struct
vfio_pci_core_device is per-device and persists across open/close cycles,
and the vfio_config_init() error path returns without calling
vfio_config_free(). So the dangling pointer outlives the failed open.
That leads to two use-after-frees on the same device:
1. Reuse. The next vfio_config_init() sees the stale pointer at
"if (vdev->msi_perm) return len;" and reuses the freed object. MSI
config accesses in vfio_pci_config_rw_single() then dereference and
call the freed perm->readfn / perm->writefn function pointers.
2. Double free. A later vfio_config_free() runs free_perm_bits() and
kfree() on the already-freed object.
Fix it by NULLing vdev->msi_perm after the kfree(), matching the
NULL-after-free discipline already used in free_perm_bits() and
vfio_config_free().
BUG: KASAN: slab-use-after-free in vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)
Read of size 8 at addr ffff88800fcc88d0 by task exploit/143
Call Trace:
...
kasan_report (mm/kasan/report.c:595)
vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)
vfio_pci_config_rw (drivers/vfio/pci/vfio_pci_config.c:1986)
vfio_pci_rw (drivers/vfio/pci/vfio_pci_core.c:1599)
vfs_read (fs/read_write.c:572)
__x64_sys_pread64 (fs/read_write.c:764)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
...
Followed on device close by a double free of the same object:
Oops: general protection fault, probably for non-canonical address
0x1f63e0e8000008: 0000 [#1] SMP KASAN NOPTI
RIP: 0010:kfree (mm/slub.c:6711)
Call Trace:
vfio_config_free (drivers/vfio/pci/vfio_pci_config.c:1861)
vfio_pci_core_disable (drivers/vfio/pci/vfio_pci_core.c:685)
vfio_pci_core_close_device (drivers/vfio/pci/vfio_pci_core.c:777)
vfio_df_close (drivers/vfio/vfio_main.c:602)
vfio_device_fops_release (drivers/vfio/vfio_main.c:648)
__fput (fs/file_table.c:512)
__x64_sys_close (fs/open.c:1496)
do_syscall_64 (arch/x86/entry/syscall_64.c:94)
...
Kernel panic - not syncing: Fatal exception
Severity
8.8 (High)
Assigner
References
8 references
Impacted products
2 products
| Vendor | Product | Version | |
|---|---|---|---|
| Linux | Linux |
Affected:
30ea32ab1951c80c6113f300fce2c70cd12659e4 , < eb84cd81040e58dd05ac190f561f2115e3367249
(git)
Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < f0eea8f9013676b42289ec35941e848b8a543e19 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < d665a1688af7f8fefd7c0eb04f2a37122ce007f4 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < 25cdd2a492d868cff1e519a60fe282909c52d385 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < 812f1db7f0755a19ef16ecdc5cec51bcabc5eda5 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < 533d0c5feef85ee6404b9f41d5564fac6971a008 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < fda8fb7e8179561693a786a7af593f6b944a21c1 (git) Affected: 30ea32ab1951c80c6113f300fce2c70cd12659e4 , < dc77acfeb979dded39b247b60fef0399536bfa77 (git) Affected: ac370e3d1f3b01519d2705cd5815d1c9d0a8812b (git) Affected: be363e27ec3c3a99793da2be6c07eafb95709c6b (git) Affected: f1b10ba5739440ca51d66f0b2949cead88d2dd02 (git) Affected: dde3433de9a067a33d67d65b9093cad3e043e49e (git) Affected: 4.4.203 , < 4.5 (semver) Affected: 4.9.203 , < 4.10 (semver) Affected: 4.14.155 , < 4.15 (semver) Affected: 4.19.85 , < 4.20 (semver) |
|
| Linux | Linux |
Affected:
4.20
Unaffected: 0 , < 4.20 (semver) Unaffected: 5.10.270 , ≤ 5.10.* (semver) Unaffected: 5.15.221 , ≤ 5.15.* (semver) Unaffected: 6.1.188 , ≤ 6.1.* (semver) Unaffected: 6.6.157 , ≤ 6.6.* (semver) Unaffected: 6.12.110 , ≤ 6.12.* (semver) Unaffected: 6.18.52 , ≤ 6.18.* (semver) Unaffected: 7.2.6 , ≤ 7.2.* (semver) Unaffected: 7.3-rc1 , ≤ * (original_commit_for_fix) |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/vfio/pci/vfio_pci_config.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "eb84cd81040e58dd05ac190f561f2115e3367249",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "f0eea8f9013676b42289ec35941e848b8a543e19",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "d665a1688af7f8fefd7c0eb04f2a37122ce007f4",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "25cdd2a492d868cff1e519a60fe282909c52d385",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "812f1db7f0755a19ef16ecdc5cec51bcabc5eda5",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "533d0c5feef85ee6404b9f41d5564fac6971a008",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "fda8fb7e8179561693a786a7af593f6b944a21c1",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"lessThan": "dc77acfeb979dded39b247b60fef0399536bfa77",
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"versionType": "git"
},
{
"status": "affected",
"version": "ac370e3d1f3b01519d2705cd5815d1c9d0a8812b",
"versionType": "git"
},
{
"status": "affected",
"version": "be363e27ec3c3a99793da2be6c07eafb95709c6b",
"versionType": "git"
},
{
"status": "affected",
"version": "f1b10ba5739440ca51d66f0b2949cead88d2dd02",
"versionType": "git"
},
{
"status": "affected",
"version": "dde3433de9a067a33d67d65b9093cad3e043e49e",
"versionType": "git"
},
{
"lessThan": "4.5",
"status": "affected",
"version": "4.4.203",
"versionType": "semver"
},
{
"lessThan": "4.10",
"status": "affected",
"version": "4.9.203",
"versionType": "semver"
},
{
"lessThan": "4.15",
"status": "affected",
"version": "4.14.155",
"versionType": "semver"
},
{
"lessThan": "4.20",
"status": "affected",
"version": "4.19.85",
"versionType": "semver"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/vfio/pci/vfio_pci_config.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"lessThan": "4.20",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.10.*",
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.6.*",
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.12.*",
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.2.*",
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.3-rc1",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.10.270",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.221",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.188",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.6.157",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.12.110",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.52",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2.6",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.3-rc1",
"versionStartIncluding": "4.20",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.4.203",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.9.203",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.14.155",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionStartIncluding": "4.19.85",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvfio/pci: clear vdev-\u003emsi_perm after freeing it on init failure\n\nvfio_msi_cap_len() lazily allocates the per-device MSI permission table:\n\n\tvdev-\u003emsi_perm = kmalloc_obj(struct perm_bits, GFP_KERNEL_ACCOUNT);\n\tif (!vdev-\u003emsi_perm)\n\t\treturn -ENOMEM;\n\n\tret = init_pci_cap_msi_perm(vdev-\u003emsi_perm, len, flags);\n\tif (ret) {\n\t\tkfree(vdev-\u003emsi_perm);\n\t\treturn ret;\t\t/* vdev-\u003emsi_perm left dangling */\n\t}\n\nWhen init_pci_cap_msi_perm() -\u003e alloc_perm_bits() fails with -ENOMEM, the\nerror path frees vdev-\u003emsi_perm but leaves the freed pointer stored in\nit. vdev-\u003emsi_perm is not re-zeroed later because struct\nvfio_pci_core_device is per-device and persists across open/close cycles,\nand the vfio_config_init() error path returns without calling\nvfio_config_free(). So the dangling pointer outlives the failed open.\n\nThat leads to two use-after-frees on the same device:\n\n1. Reuse. The next vfio_config_init() sees the stale pointer at\n \"if (vdev-\u003emsi_perm) return len;\" and reuses the freed object. MSI\n config accesses in vfio_pci_config_rw_single() then dereference and\n call the freed perm-\u003ereadfn / perm-\u003ewritefn function pointers.\n\n2. Double free. A later vfio_config_free() runs free_perm_bits() and\n kfree() on the already-freed object.\n\nFix it by NULLing vdev-\u003emsi_perm after the kfree(), matching the\nNULL-after-free discipline already used in free_perm_bits() and\nvfio_config_free().\n\n BUG: KASAN: slab-use-after-free in vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)\n Read of size 8 at addr ffff88800fcc88d0 by task exploit/143\n Call Trace:\n ...\n kasan_report (mm/kasan/report.c:595)\n vfio_pci_config_rw_single (drivers/vfio/pci/vfio_pci_config.c:1961)\n vfio_pci_config_rw (drivers/vfio/pci/vfio_pci_config.c:1986)\n vfio_pci_rw (drivers/vfio/pci/vfio_pci_core.c:1599)\n vfs_read (fs/read_write.c:572)\n __x64_sys_pread64 (fs/read_write.c:764)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n ...\n\nFollowed on device close by a double free of the same object:\n\n Oops: general protection fault, probably for non-canonical address\n 0x1f63e0e8000008: 0000 [#1] SMP KASAN NOPTI\n RIP: 0010:kfree (mm/slub.c:6711)\n Call Trace:\n vfio_config_free (drivers/vfio/pci/vfio_pci_config.c:1861)\n vfio_pci_core_disable (drivers/vfio/pci/vfio_pci_core.c:685)\n vfio_pci_core_close_device (drivers/vfio/pci/vfio_pci_core.c:777)\n vfio_df_close (drivers/vfio/vfio_main.c:602)\n vfio_device_fops_release (drivers/vfio/vfio_main.c:648)\n __fput (fs/file_table.c:512)\n __x64_sys_close (fs/open.c:1496)\n do_syscall_64 (arch/x86/entry/syscall_64.c:94)\n ...\n Kernel panic - not syncing: Fatal exception"
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 8.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The UAF is reached only via local VFIO char-device operations: open of /dev/vfio/$GROUP or /dev/vfio/devices/vfioN, then pread/pwrite of the PCI config region through vfio_pci_core_read/write into vfio_pci_config_rw_single(). There is no network or packet path into vfio_msi_cap_len().\nAC:L - After any failed vfio_config_init() plants the dangling vdev-\u003emsi_perm, the attacker retries GET_DEVICE_FD/BIND_IOMMUFD on the same persistent vdev and deterministically calls the freed perm-\u003ereadfn/writefn via MSI config accesses. The attacker controls that open/read sequence; no victim race or uncontrolled layout is required.\nPR:L - vfio_pci_core_enable() and vfio_pci_config_rw() have no capable() check on the normal IOMMU path (CAP_SYS_RAWIO is only for noiommu). Access is gated by /dev/vfio node permissions, which libvirt, kubevirt, and cloud GPU/NIC passthrough routinely grant to an unprivileged qemu user or tenant.\nUI:N - The attacker performs the VFIO open, retry, and MSI config-space pread/pwrite themselves. Prior admin binding of the PCI device to vfio-pci is deployment configuration, not victim interaction during exploitation.\nS:C - struct vfio_pci_core_device persists across open/close, so a failed open can leave a dangling msi_perm that a later tenant VM reuses. QEMU services guest PCI config cycles with VFIO pread/pwrite, so a passthrough guest can invoke the freed host function pointers and cross the VFIO/IOMMU guest-to-host boundary.\nC:H - The next successful open reuses the freed perm_bits and MSI config reads call perm-\u003ereadfn on that object. Reclaiming the slab slot yields an arbitrary kernel-read primitive, which CVSS kernel guidance scores High for use-after-free.\nI:H - MSI config writes call the freed perm-\u003ewritefn, and a later close double-frees the same object in vfio_config_free(). That UAF/double-free of a structure with function pointers is exploitable for arbitrary kernel write and control-flow hijack.\nA:H - The report shows a KASAN slab-use-after-free in vfio_pci_config_rw_single() followed by a general-protection fault in kfree() during vfio_config_free() that panics the host, so availability impact is a kernel oops/panic."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-09-16T14:38:28.611Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/eb84cd81040e58dd05ac190f561f2115e3367249"
},
{
"url": "https://git.kernel.org/stable/c/f0eea8f9013676b42289ec35941e848b8a543e19"
},
{
"url": "https://git.kernel.org/stable/c/d665a1688af7f8fefd7c0eb04f2a37122ce007f4"
},
{
"url": "https://git.kernel.org/stable/c/25cdd2a492d868cff1e519a60fe282909c52d385"
},
{
"url": "https://git.kernel.org/stable/c/812f1db7f0755a19ef16ecdc5cec51bcabc5eda5"
},
{
"url": "https://git.kernel.org/stable/c/533d0c5feef85ee6404b9f41d5564fac6971a008"
},
{
"url": "https://git.kernel.org/stable/c/fda8fb7e8179561693a786a7af593f6b944a21c1"
},
{
"url": "https://git.kernel.org/stable/c/dc77acfeb979dded39b247b60fef0399536bfa77"
}
],
"title": "vfio/pci: clear vdev-\u003emsi_perm after freeing it on init failure",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-89777",
"datePublished": "2026-09-16T08:48:17.754Z",
"dateReserved": "2026-09-11T19:38:34.765Z",
"dateUpdated": "2026-09-16T14:38:28.611Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
Loading…
Trend slope:
-
(linear fit over daily sighting counts)
Show additional events:
Loading…
Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
Loading…
Loading…
The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
Loading…
Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
Loading…
Loading…