{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-52969","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","state":"PUBLISHED","assignerShortName":"Linux","dateReserved":"2026-06-09T07:44:35.375Z","datePublished":"2026-06-24T16:28:48.085Z","dateUpdated":"2026-06-30T12:09:43.762Z"},"containers":{"cna":{"providerMetadata":{"orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux","dateUpdated":"2026-06-24T16:28:48.085Z"},"descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: Reject wrapped offset in kvm_reset_dirty_gfn()\n\nkvm_reset_dirty_gfn() guards the gfn range with\n\n\tif (!memslot || (offset + __fls(mask)) >= memslot->npages)\n\t\treturn;\n\nbut offset is u64 and the addition is unchecked.  The check can be\nsilently bypassed by a u64 wrap.\n\nThe dirty ring backing those entries is MAP_SHARED at\nKVM_DIRTY_LOG_PAGE_OFFSET of the vcpu fd, so the VMM can rewrite the\nslot and offset fields of any entry between when the kernel pushes\nthem and when KVM_RESET_DIRTY_RINGS consumes them.  On reset,\nkvm_dirty_ring_reset() re-reads the values via READ_ONCE() and feeds\nthem straight back into this check; only the flags handshake is\ntreated as the handover, the slot/offset payload is taken on trust.\n\nCrafting two entries\n\n\tentry[i].offset   = 0xffffffffffffffc1\n\tentry[i+1].offset = 0\n\nmakes the coalescing loop in kvm_dirty_ring_reset() compute\n\n\tdelta = (s64)(0 - 0xffffffffffffffc1) = 63\n\nwhich falls in [0, BITS_PER_LONG), so it folds entry[i+1] into the\nexisting mask by setting bit 63.  The trailing kvm_reset_dirty_gfn()\ncall then sees offset = 0xffffffffffffffc1 and __fls(mask) = 63;\nthe sum is 0 in u64 and the bounds check passes.\n\nThat offset propagates into kvm_arch_mmu_enable_log_dirty_pt_masked()\nunchanged.  On the legacy MMU path -- kvm_memslots_have_rmaps() ==\ntrue, i.e. shadow paging, any VM that has allocated shadow roots, or\na write-tracked slot -- it reaches gfn_to_rmap(), which indexes\nslot->arch.rmap[0][] with a near-U64_MAX gfn.  That is an\nout-of-bounds load of a kvm_rmap_head, followed by a conditional\nclear of PT_WRITABLE_MASK in whatever the loaded pointer points at.\nThe path is reachable from any process holding /dev/kvm.\n\nRange-check offset on its own first, so the addition cannot wrap.\nmemslot->npages is bounded well below U64_MAX, so once offset <\nnpages holds, offset + __fls(mask) (with __fls(mask) < BITS_PER_LONG)\nstays in range."}],"affected":[{"product":"Linux","vendor":"Linux","defaultStatus":"unaffected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["virt/kvm/dirty_ring.c"],"versions":[{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"74f1a22f7a80f03d28ad8551a2d25d563433addf","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"0eb281eb95b2d4eea4db1da5fe91023aecc97095","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"01b71b930f15728aa8599478a7ce90c19dcd9fc2","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"b315b033a877b1ee6d827810b5d7bb4392ffcf8d","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"0d419c23bb11b5c9664de777c47c1f04a235882d","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"ecf9b3ea7847fe14f34b8c41f00de1eb95c747da","status":"affected","versionType":"git"},{"version":"fb04a1eddb1a65b6588a021bdc132270d5ae48bb","lessThan":"577a8d3bae0531f0e5ccfac919cd8192f920a804","status":"affected","versionType":"git"}]},{"product":"Linux","vendor":"Linux","defaultStatus":"affected","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["virt/kvm/dirty_ring.c"],"versions":[{"version":"5.11","status":"affected"},{"version":"0","lessThan":"5.11","status":"unaffected","versionType":"semver"},{"version":"5.15.209","lessThanOrEqual":"5.15.*","status":"unaffected","versionType":"semver"},{"version":"6.1.175","lessThanOrEqual":"6.1.*","status":"unaffected","versionType":"semver"},{"version":"6.6.141","lessThanOrEqual":"6.6.*","status":"unaffected","versionType":"semver"},{"version":"6.12.91","lessThanOrEqual":"6.12.*","status":"unaffected","versionType":"semver"},{"version":"6.18.33","lessThanOrEqual":"6.18.*","status":"unaffected","versionType":"semver"},{"version":"7.0.10","lessThanOrEqual":"7.0.*","status":"unaffected","versionType":"semver"},{"version":"7.1","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":"5.11","versionEndExcluding":"5.15.209"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.1.175"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.6.141"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.12.91"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"6.18.33"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.0.10"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.11","versionEndExcluding":"7.1"}]}]}],"references":[{"url":"https://git.kernel.org/stable/c/74f1a22f7a80f03d28ad8551a2d25d563433addf"},{"url":"https://git.kernel.org/stable/c/0eb281eb95b2d4eea4db1da5fe91023aecc97095"},{"url":"https://git.kernel.org/stable/c/01b71b930f15728aa8599478a7ce90c19dcd9fc2"},{"url":"https://git.kernel.org/stable/c/b315b033a877b1ee6d827810b5d7bb4392ffcf8d"},{"url":"https://git.kernel.org/stable/c/0d419c23bb11b5c9664de777c47c1f04a235882d"},{"url":"https://git.kernel.org/stable/c/ecf9b3ea7847fe14f34b8c41f00de1eb95c747da"},{"url":"https://git.kernel.org/stable/c/577a8d3bae0531f0e5ccfac919cd8192f920a804"}],"title":"KVM: Reject wrapped offset in kvm_reset_dirty_gfn()","x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"cpes":["cpe:/o:redhat:enterprise_linux:10"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 10","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:6"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 6","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:7"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 7","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:8"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 8","vendor":"Red Hat"},{"cpes":["cpe:/o:redhat:enterprise_linux:9"],"defaultStatus":"unaffected","product":"Red Hat Enterprise Linux 9","vendor":"Red Hat"}],"datePublic":"2026-06-24T00:00:00.000Z","descriptions":[{"lang":"en","value":"A flaw was found in the Linux kernel's Kernel-based Virtual Machine (KVM) component. A local attacker with access to /dev/kvm could exploit an integer overflow vulnerability in the kvm_reset_dirty_gfn() function. By manipulating dirty ring entries, the attacker can bypass a bounds check, leading to an out-of-bounds memory access. This could result in information disclosure or potentially cause a denial of service."}],"metrics":[{"other":{"content":{"namespace":"https://access.redhat.com/security/updates/classification/","value":"Important"},"type":"Red Hat severity rating"}},{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","description":"Integer Overflow or Wraparound","lang":"en","type":"CWE"}]}],"references":[{"tags":["vdb-entry","x_refsource_REDHAT"],"url":"https://access.redhat.com/security/cve/CVE-2026-52969"},{"name":"RHBZ#2492434","tags":["issue-tracking","x_refsource_REDHAT"],"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2492434"},{"tags":["x_sadp-csaf-vex"],"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-52969.json"}],"timeline":[{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Reported to Red Hat."},{"lang":"en","time":"2026-06-24T00:00:00.000Z","value":"Made public."}],"title":"kernel: KVM: Reject wrapped offset in kvm_reset_dirty_gfn()","x_adpType":"supplier","x_generator":{"engine":"sadp-cli 1.0.0"},"providerMetadata":{"orgId":"0b0ca135-0b70-47e7-9f44-1890c2a1c46c","shortName":"redhat-SADP","dateUpdated":"2026-06-30T12:09:43.762Z"}}]}}