cbcvebase.
CVE-2023-54137
published 2025-12-24

CVE-2023-54137: In the Linux kernel, the following vulnerability has been resolved: vfio/type1: fix cap_migration information leak Fix an information leak where an…

PriorityP420medium5.5
EPSS
0.19%
8.6th percentile
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 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.

Affected

17 ranges
VendorProductVersion rangeFixed in
debianlinux< linux 6.1.55-1 (bookworm)linux 6.1.55-1 (bookworm)
linuxlinux——
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < ad83d83dd891244de0d07678b257dc976db7c132ad83d83dd891244de0d07678b257dc976db7c132
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < 13fd667db999bffb557c5de7adb3c14f1713dd5113fd667db999bffb557c5de7adb3c14f1713dd51
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < f6f300ecc196d243c02adeb9ee0c62c677c24bfbf6f300ecc196d243c02adeb9ee0c62c677c24bfb
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < cbac29a1caa49a34e131394e1f4d924a76d8b0c9cbac29a1caa49a34e131394e1f4d924a76d8b0c9
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < 1b5feb8497cdb5b9962db2700814bffbc030fb4a1b5feb8497cdb5b9962db2700814bffbc030fb4a
linuxlinux>= ad721705d09c62f0d108a6b4f59867ebfd592c90 < cd24e2a60af633f157d7e59c0a6dba64f131c0b1cd24e2a60af633f157d7e59c0a6dba64f131c0b1
linuxlinux_kernel>= 0 < 5.10.197-15.10.197-1
linuxlinux_kernel>= 0 < 6.1.55-16.1.55-1
linuxlinux_kernel>= 0 < 6.5.3-16.5.3-1
linuxlinux_kernel>= 0 < 6.5.3-16.5.3-1
linuxlinux_kernel>= 5.11.0 < 5.15.1325.15.132
linuxlinux_kernel>= 5.16.0 < 6.1.536.1.53
linuxlinux_kernel>= 5.8.0 < 5.10.1955.10.195
linuxlinux_kernel>= 6.2.0 < 6.4.166.4.16
linuxlinux_kernel>= 6.5.0 < 6.5.36.5.3
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