vfio/pci: clear vdev->msi_perm after freeing it on init failure

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-89777
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-16 09:17:08 UTC
Updated2026-09-16 15:18:06 UTC
DescriptionIn 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

Risk And Classification

Primary CVSS: v3.1 8.8 HIGH from 416baaa9-dc9f-4396-8d5f-8c081fb06d67

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS: 0.002100000 probability, percentile 0.114460000 (date 2026-09-16)

VersionSourceTypeScoreSeverityVector
3.1416baaa9-dc9f-4396-8d5f-8c081fb06d67Secondary8.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
3.1CNADECLARED8.8HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

CVSS v3.1 Breakdown

Attack Vector
Local
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 eb84cd81040e58dd05ac190f561f2115e3367249 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 f0eea8f9013676b42289ec35941e848b8a543e19 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 d665a1688af7f8fefd7c0eb04f2a37122ce007f4 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 25cdd2a492d868cff1e519a60fe282909c52d385 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 812f1db7f0755a19ef16ecdc5cec51bcabc5eda5 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 533d0c5feef85ee6404b9f41d5564fac6971a008 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 fda8fb7e8179561693a786a7af593f6b944a21c1 git Not specified
CNA Linux Linux affected 30ea32ab1951c80c6113f300fce2c70cd12659e4 dc77acfeb979dded39b247b60fef0399536bfa77 git Not specified
CNA Linux Linux affected ac370e3d1f3b01519d2705cd5815d1c9d0a8812b git Not specified
CNA Linux Linux affected be363e27ec3c3a99793da2be6c07eafb95709c6b git Not specified
CNA Linux Linux affected f1b10ba5739440ca51d66f0b2949cead88d2dd02 git Not specified
CNA Linux Linux affected dde3433de9a067a33d67d65b9093cad3e043e49e git Not specified
CNA Linux Linux affected 4.4.203 4.5 semver Not specified
CNA Linux Linux affected 4.9.203 4.10 semver Not specified
CNA Linux Linux affected 4.14.155 4.15 semver Not specified
CNA Linux Linux affected 4.19.85 4.20 semver Not specified
CNA Linux Linux affected 4.20 Not specified
CNA Linux Linux unaffected 4.20 semver Not specified
CNA Linux Linux unaffected 5.10.270 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.221 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.188 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.157 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.110 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.52 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.6 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3-rc1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/25cdd2a492d868cff1e519a60fe282909c52d385 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/fda8fb7e8179561693a786a7af593f6b944a21c1 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/d665a1688af7f8fefd7c0eb04f2a37122ce007f4 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/533d0c5feef85ee6404b9f41d5564fac6971a008 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/812f1db7f0755a19ef16ecdc5cec51bcabc5eda5 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/dc77acfeb979dded39b247b60fef0399536bfa77 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/f0eea8f9013676b42289ec35941e848b8a543e19 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/eb84cd81040e58dd05ac190f561f2115e3367249 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

© CVE.report 2026

Use of this information constitutes acceptance for use in an AS IS condition. There are NO warranties, implied or otherwise, with regard to this information or its use. Any use of this information is at the user's risk. It is the responsibility of user to evaluate the accuracy, completeness or usefulness of any information, opinion, advice or other content. EACH USER WILL BE SOLELY RESPONSIBLE FOR ANY consequences of his or her direct or indirect use of this web site. ALL WARRANTIES OF ANY KIND ARE EXPRESSLY DISCLAIMED. This site will NOT BE LIABLE FOR ANY DIRECT, INDIRECT or any other kind of loss.

CVE, CWE, and OVAL are registred trademarks of The MITRE Corporation and the authoritative source of CVE content is MITRE's CVE web site. This site includes MITRE data granted under the following license.

Free CVE JSON API cve.report/api

CVE.report and Source URL Uptime Status status.cve.report