vfio/pci: clear vdev->msi_perm after freeing it on init failure
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/v
CVE-2026-89777
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-89777
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "eb84cd81040e58dd05ac190f561f2115e3367249",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "f0eea8f9013676b42289ec35941e848b8a543e19",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "d665a1688af7f8fefd7c0eb04f2a37122ce007f4",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "25cdd2a492d868cff1e519a60fe282909c52d385",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "812f1db7f0755a19ef16ecdc5cec51bcabc5eda5",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "533d0c5feef85ee6404b9f41d5564fac6971a008",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "fda8fb7e8179561693a786a7af593f6b944a21c1",
"versionType": "git"
},
{
"status": "affected",
"version": "30ea32ab1951c80c6113f300fce2c70cd12659e4",
"lessThan": "dc77acfeb979dded39b247b60fef0399536bfa77",
"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"
},
{
"status": "affected",
"version": "4.4.203",
"lessThan": "4.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.9.203",
"lessThan": "4.10",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.14.155",
"lessThan": "4.15",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.85",
"lessThan": "4.20",
"versionType": "semver"
}
],
"programFiles": [
"drivers/vfio/pci/vfio_pci_config.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.20"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"drivers/vfio/pci/vfio_pci_config.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89777
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35243 · Revision 1
- Added to Heist Feed
- Publisher date