CVE-2023-54137
Vulnérabilité non évaluée dans Linux (Linux)
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.
Gravité et risque d'exploitation
CVE-2023-54137 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.21 %, ce qui la place devant 11.1 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <=6.1.*, <cd24e2a60af633f157d7e59c0a6dba64f131c0b1, 0, <5.8, 6.5.3, <=5.10.*, <1b5feb8497cdb5b9962db2700814bffbc030fb4a, 6.4.16, 6.6, <13fd667db999bffb557c5de7adb3c14f1713dd51, 5.15.132, ad721705d09c62f0d108a6b4f59867ebfd592c90, 5.10.195, <cbac29a1caa49a34e131394e1f4d924a76d8b0c9, <=*, <=5.15.*, <=6.5.*, <f6f300ecc196d243c02adeb9ee0c62c677c24bfb, <ad83d83dd891244de0d07678b257dc976db7c132, 5.8, 6.1.53, <=6.4.*) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://git.kernel.org/stable/c/ad83d83dd891244de0d07678b257dc976db7c132
- https://git.kernel.org/stable/c/13fd667db999bffb557c5de7adb3c14f1713dd51
- https://git.kernel.org/stable/c/f6f300ecc196d243c02adeb9ee0c62c677c24bfb
- https://git.kernel.org/stable/c/cbac29a1caa49a34e131394e1f4d924a76d8b0c9
- https://git.kernel.org/stable/c/1b5feb8497cdb5b9962db2700814bffbc030fb4a
- https://git.kernel.org/stable/c/cd24e2a60af633f157d7e59c0a6dba64f131c0b1
