In the Linux kernel, the following vulnerability has been resolved:

vfio/type1: fix cap_migration information leak

Fix an information leak where an uninitialized hole in struct
vfio_iommu_type1_info_cap_migration on the stack is exposed to userspace.

The definition of struct vfio_iommu_type1_info_cap_migration contains a hole as
shown in this pahole(1) output:

struct vfio_iommu_type1_info_cap_migration {
struct vfio_info_cap_header header; /* 0 8 */
__u32 flags; /* 8 4 */

/* XXX 4 bytes hole, try to pack */

__u64 pgsize_bitmap; /* 16 8 */
__u64 max_dirty_bitmap_size; /* 24 8 */

/* size: 32, cachelines: 1, members: 4 */
/* sum members: 28, holes: 1, sum holes: 4 */
/* last cacheline: 32 bytes */
};

The cap_mig variable is filled in without initializing the hole:

static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
struct vfio_info_cap *caps)
{
struct vfio_iommu_type1_info_cap_migration cap_mig;

cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
cap_mig.header.version = 1;

cap_mig.flags = 0;
/* support minimum pgsize */
cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;

return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
}

The structure is then copied to a temporary location on the heap. At this point
it's already too late and ioctl(VFIO_IOMMU_GET_INFO) copies it to userspace
later:

int vfio_info_add_capability(struct vfio_info_cap *caps,
struct vfio_info_cap_header *cap, size_t size)
{
struct vfio_info_cap_header *header;

header = vfio_info_cap_add(caps, size, cap->id, cap->version);
if (IS_ERR(header))
return PTR_ERR(header);

memcpy(header + 1, cap + 1, size - sizeof(*header));

return 0;
}

This issue was found by code inspection.

No CVSS v4.0

Attack Vector Local

Attack Complexity Low

Privileges Required Low

Scope Unchanged

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00036.

Key SSVC decision points have not yet been added.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions
Linux Linux unaffected
Version Status Constraints
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < ad83d83dd891244de0d07678b257dc976db7c132
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < 13fd667db999bffb557c5de7adb3c14f1713dd51
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < f6f300ecc196d243c02adeb9ee0c62c677c24bfb
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < cbac29a1caa49a34e131394e1f4d924a76d8b0c9
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < 1b5feb8497cdb5b9962db2700814bffbc030fb4a
ad721705d09c62f0d108a6b4f59867ebfd592c90 affected < cd24e2a60af633f157d7e59c0a6dba64f131c0b1
Linux Linux affected
Version Status Constraints
5.8 affected —
0 unaffected < 5.8
5.10.195 unaffected ≤ 5.10.*
5.15.132 unaffected ≤ 5.15.*
6.1.53 unaffected ≤ 6.1.*
6.4.16 unaffected ≤ 6.4.*
6.5.3 unaffected ≤ 6.5.*
6.6 unaffected ≤ *

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References
Link Providers
https://git.kernel.org/stable/c/13fd667db999bffb557c5de7adb3c14f1713dd51 cve-icon cve-icon
https://git.kernel.org/stable/c/1b5feb8497cdb5b9962db2700814bffbc030fb4a cve-icon cve-icon
https://git.kernel.org/stable/c/ad83d83dd891244de0d07678b257dc976db7c132 cve-icon cve-icon
https://git.kernel.org/stable/c/cbac29a1caa49a34e131394e1f4d924a76d8b0c9 cve-icon cve-icon
https://git.kernel.org/stable/c/cd24e2a60af633f157d7e59c0a6dba64f131c0b1 cve-icon cve-icon
https://git.kernel.org/stable/c/f6f300ecc196d243c02adeb9ee0c62c677c24bfb cve-icon cve-icon
https://lore.kernel.org/linux-cve-announce/2025122422-CVE-2023-54137-1873@gregkh/T cve-icon
https://nvd.nist.gov/vuln/detail/CVE-2023-54137 cve-icon
https://www.cve.org/CVERecord?id=CVE-2023-54137 cve-icon
History

Thu, 25 Dec 2025 00:15:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

 cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Low

Wed, 24 Dec 2025 13:15:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: vfio/type1: fix cap_migration information leak Fix an information leak where an uninitialized hole in struct vfio_iommu_type1_info_cap_migration on the stack is exposed to userspace. The definition of struct vfio_iommu_type1_info_cap_migration contains a hole as shown in this pahole(1) output: struct vfio_iommu_type1_info_cap_migration { struct vfio_info_cap_header header; /* 0 8 */ __u32 flags; /* 8 4 */ /* XXX 4 bytes hole, try to pack */ __u64 pgsize_bitmap; /* 16 8 */ __u64 max_dirty_bitmap_size; /* 24 8 */ /* size: 32, cachelines: 1, members: 4 */ /* sum members: 28, holes: 1, sum holes: 4 */ /* last cacheline: 32 bytes */ }; The cap_mig variable is filled in without initializing the hole: static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu, struct vfio_info_cap *caps) { struct vfio_iommu_type1_info_cap_migration cap_mig; cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION; cap_mig.header.version = 1; cap_mig.flags = 0; /* support minimum pgsize */ cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap); cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX; return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig)); } The structure is then copied to a temporary location on the heap. At this point it's already too late and ioctl(VFIO_IOMMU_GET_INFO) copies it to userspace later: int vfio_info_add_capability(struct vfio_info_cap *caps, struct vfio_info_cap_header *cap, size_t size) { struct vfio_info_cap_header *header; header = vfio_info_cap_add(caps, size, cap->id, cap->version); if (IS_ERR(header)) return PTR_ERR(header); memcpy(header + 1, cap + 1, size - sizeof(*header)); return 0; } This issue was found by code inspection.
Title vfio/type1: fix cap_migration information leak
First Time appeared Linux
Linux linux Kernel
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
References

Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2025-12-24T13:06:52.689Z

Reserved: 2025-12-24T13:02:52.522Z

Link: CVE-2023-54137

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-12-24T13:16:15.693

Modified: 2025-12-29T15:58:13.147

Link: CVE-2023-54137

cve-icon Redhat

Severity : Low

Publid Date: 2025-12-24T00:00:00Z

Links: CVE-2023-54137 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses

No weakness.