{"dataType":"CVE_RECORD","cveMetadata":{"cveId":"CVE-2024-35791","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2024-05-17T12:19:12.339Z","datePublished":"2024-05-17T12:24:49.520Z","dateUpdated":"2026-08-05T11:29:57.222Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-08-05T11:29:57.222Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()\n\nDo the cache flush of converted pages in svm_register_enc_region() before\ndropping kvm->lock to fix use-after-free issues where region and/or its\narray of pages could be freed by a different task, e.g. if userspace has\n__unregister_enc_region_locked() already queued up for the region.\n\nNote, the \"obvious\" alternative of using local variables doesn't fully\nresolve the bug, as region->pages is also dynamically allocated.  I.e. the\nregion structure itself would be fine, but region->pages could be freed.\n\nFlushing multiple pages under kvm->lock is unfortunate, but the entire\nflow is a rare slow path, and the manual flush is only needed on CPUs that\nlack coherency for encrypted memory."}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerable code is reached only through the `KVM_MEMORY_ENCRYPT_REG_REGION`/`KVM_MEMORY_ENCRYPT_UNREG_REGION` ioctls on a local KVM VM file descriptor obtained from /dev/kvm. There is no remote or network-facing path to `sev_mem_enc_register_region()`.\nAC:L - The attacker controls both sides of the race, issuing the register and unregister ioctls from two threads it owns, and can widen the window arbitrarily by registering a large region since `sev_clflush_pages()` loops per page with `cond_resched()` after the lock is dropped. Nothing about winning the race depends on conditions outside the attacker's influence.\nPR:L - No capability check exists on the path — neither `kvm_arch_vm_ioctl()`'s `KVM_MEMORY_ENCRYPT_*_REGION` cases nor `sev_guest_init()` require CAP_SYS_ADMIN — so any local user with access to /dev/kvm (commonly granted via the `kvm` group or permissive device modes on virtualization hosts) can create an SEV VM and trigger the UAF.\nUI:N - The attacking process performs both ioctls itself; no action by any other user or victim process is needed.\nS:U - The attacker is host userspace (the VMM process) corrupting host kernel memory, so the vulnerable component and impacted component share the same security authority. This is not a guest-to-host escape, as the guest cannot issue these ioctls.\nC:H - The use-after-free reads a freed, sprayable kvmalloc'd `struct page *` array and then maps and flushes those attacker-influenceable pointers via `kmap_local_page()`, exposing arbitrary kernel/physical memory and enabling information disclosure once the freed slabs are reallocated.\nI:H - Two heap objects (`region` and `region->pages`) are used after being freed and can be reallocated with attacker-controlled contents, giving the heap-spray primitives typical of exploitable UAFs; `clflush_cache_range()` on a bogus mapping additionally acts on memory outside the intended range.\nA:H - Dereferencing freed `region->npages`/`region->pages` and calling `kmap_local_page()` on garbage `struct page` pointers reliably produces an oops or panic, taking the host kernel down."}]}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/svm/sev.c"],"versions":[{"version":"4f627ecde7329e476a077bb0590db8f27bb8f912","lessThan":"2d13b79640b147bd77c34a5998533b2021a4122d","status":"affected","versionType":"git"},{"version":"19a23da53932bc8011220bd8c410cb76012de004","lessThan":"e126b508ed2e616d679d85fca2fbe77bb48bbdd7","status":"affected","versionType":"git"},{"version":"19a23da53932bc8011220bd8c410cb76012de004","lessThan":"4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865","status":"affected","versionType":"git"},{"version":"19a23da53932bc8011220bd8c410cb76012de004","lessThan":"12f8e32a5a389a5d58afc67728c76e61beee1ad4","status":"affected","versionType":"git"},{"version":"19a23da53932bc8011220bd8c410cb76012de004","lessThan":"f6d53d8a2617dd58c89171a6b9610c470ebda38a","status":"affected","versionType":"git"},{"version":"19a23da53932bc8011220bd8c410cb76012de004","lessThan":"5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807","status":"affected","versionType":"git"},{"version":"f1ecde00ce1694597f923f0d25f7a797c5243d99","status":"affected","versionType":"git"},{"version":"848bcb0a1d96f67d075465667d3a1ad4af56311e","status":"affected","versionType":"git"},{"version":"5.10.15","lessThan":"5.10.215","status":"affected","versionType":"semver"},{"version":"4.19.176","lessThan":"4.20","status":"affected","versionType":"semver"},{"version":"5.4.98","lessThan":"5.5","status":"affected","versionType":"semver"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/x86/kvm/svm/sev.c"],"versions":[{"version":"5.11","status":"affected"},{"version":"0","lessThan":"5.11","status":"unaffected","versionType":"semver"},{"version":"5.10.215","lessThanOrEqual":"5.10.*","status":"unaffected","versionType":"semver"},{"version":"5.15.154","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.84","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.24","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.7.12","lessThanOrEqual":"6.7.*","status":"unaffected","versionType":"semver"},{"version":"6.8","lessThanOrEqual":"*","status":"unaffected","versionType":"original_commit_for_fix"}]}],"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.15","versionEndExcluding":"5.10.215"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"5.15.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.84"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.24"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.7.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.8"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.19.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.4.98"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/2d13b79640b147bd77c34a5998533b2021a4122d"},{"url":"https://git.kernel.org/stable/c/e126b508ed2e616d679d85fca2fbe77bb48bbdd7"},{"url":"https://git.kernel.org/stable/c/4868c0ecdb6cfde7c70cf478c46e06bb9c7e5865"},{"url":"https://git.kernel.org/stable/c/12f8e32a5a389a5d58afc67728c76e61beee1ad4"},{"url":"https://git.kernel.org/stable/c/f6d53d8a2617dd58c89171a6b9610c470ebda38a"},{"url":"https://git.kernel.org/stable/c/5ef1d8c1ddbf696e47b226e11888eaf8d9e8e807"}],"title":"KVM: SVM: Flush pages under kvm->lock to fix UAF in svm_register_enc_region()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"providerMetadata":{"orgId":"af854a3a-2127-422b-91ae-364da2661108","shortName":"CVE","dateUpdated":"2024-08-02T03:21:47.497Z"},"title":"CVE Program 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