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CVE-2026-53360: Linux, грешка в паметта

8.8

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се локално, без особени условия, с обикновен потребителски вход и без действие от потребителя.

CVE радар: още уязвимости от този вид

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Require in-GHCB scratch area if GHCB v2+ is in use As per the GHCB spec, when using GHCB v2+ require the software scratch area to reside in the GHCB's shared buffer. Note, things like Page State Change (PSC) requests _rely_ on this behavior, as the guest can't provide a length when making the request, i.e. the size of the guest payload is bounded by the size of the shared buffer. Failure to force usage of the GHCB, and a slew of other flaws, lets a malicious SNP guest corrupt host kernel heap memory, and leak host heap layout information. setup_vmgexit_scratch() allocates a buffer via kvzalloc(exit_info_2), where exit_info_2 is guest-controlled. With exit_info_2=24, this yields a 24-byte allocation in kmalloc-cg-32 (32-byte slab objects). The buffer holds an 8-byte psc_hdr followed by 8-byte psc_entry structs, so only entries[0] and entries[1] are in-bounds. snp_begin_psc() validates end_entry against VMGEXIT_PSC_MAX_COUNT (253) but NOT against the actual buffer size: idx_end = hdr->end_entry; if (idx_end >= VMGEXIT_PSC_MAX_COUNT) { // checks 253, not buffer snp_complete_psc(svm, ...); return 1; } for (idx = idx_start; idx <= idx_end; idx++) { entry_start = entries[idx]; // OOB when idx >= 2 The guest sets end_entry=10+, causing the host to iterate entries[2+] which are OOB into adjacent slab objects. For each OOB entry: - The host reads 8 bytes (OOB READ / info leak oracle) - If the data passes PSC validation, __snp_complete_one_psc() writes cur_page = 1 or 512 into the entry (OOB WRITE, sev.c:3806) - If validation fails, the error response reveals whether adjacent memory is zero vs non-zero (information disclosure to guest) The guest controls allocation size (exit_info_2), entry range (cur_entry/end_entry), and can fire unlimited VMGEXITs to repeatedly hit different slab positions. By exploiting

Засегнати продукти

  • Linux Linux: 4af663c2f64a8d252e690c60cf8b8abf22dc2951 преди bf9ba093fbb83c0c9a3dedd50efec29424eca2fc; 4af663c2f64a8d252e690c60cf8b8abf22dc2951 преди c9b4198fbc6ed99a9da4bee9f74bb730f926c9ae; 4af663c2f64a8d252e690c60cf8b8abf22dc2951 преди b328ede59ac34e7998e1eee5e5f0cc26c2a91846; 4af663c2f64a8d252e690c60cf8b8abf22dc2951 преди db3f2195d29344a3cf1e9dd9ab7f21ced7308cf7
  • Linux Linux: 6.10; преди 6.10; 6.12.93 до 6.12.*; 6.18.35 до 6.18.*; 7.0.12 до 7.0.*; от 7.1 нататък

Вид слабост

История

  • 4 юли 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-53360: Linux, грешка в паметта | freedomonline.bg