{"id":"CVE-2025-71155","state":"PUBLISHED","title":"KVM: s390: Fix gmap_helper_zap_one_page() again","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Fix gmap_helper_zap_one_page() again\n\nA few checks were missing in gmap_helper_zap_one_page(), which can lead\nto memory corruption in the guest under specific circumstances.\n\nAdd the missing checks.","publishedAt":"2026-01-23T14:25:54.663Z","updatedAt":"2026-08-05T12:12:23.055Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5deafa27d9ae040b75d392f60b12e300b42b4792","status":"affected","lessThan":"2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7","versionType":"git"},{"version":"5deafa27d9ae040b75d392f60b12e300b42b4792","status":"affected","lessThan":"2f393c228cc519ddf19b8c6c05bf15723241aa96","versionType":"git"},{"version":"919efcadb63fc3d3a82c3de7194140e0b28903dc","status":"affected","versionType":"git"},{"version":"6.17.4","status":"affected","lessThan":"6.18","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/mm/gmap_helpers.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.4","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/mm/gmap_helpers.c"]}],"references":["https://git.kernel.org/stable/c/2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7","https://git.kernel.org/stable/c/2f393c228cc519ddf19b8c6c05bf15723241aa96"],"weaknesses":[],"ingestedAt":"2026-10-29T20:10:04.440Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/71xxx/CVE-2025-71155.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-71155","state":"PUBLISHED","datePublished":"2026-01-23T14:25:54.663Z","dateUpdated":"2026-08-05T12:12:23.055Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:30:19.663Z"},"containers":{"cna":{"title":"KVM: s390: Fix gmap_helper_zap_one_page() again","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Fix gmap_helper_zap_one_page() again\n\nA few checks were missing in gmap_helper_zap_one_page(), which can lead\nto memory corruption in the guest under specific circumstances.\n\nAdd the missing checks."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"5deafa27d9ae040b75d392f60b12e300b42b4792","status":"affected","lessThan":"2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7","versionType":"git"},{"version":"5deafa27d9ae040b75d392f60b12e300b42b4792","status":"affected","lessThan":"2f393c228cc519ddf19b8c6c05bf15723241aa96","versionType":"git"},{"version":"919efcadb63fc3d3a82c3de7194140e0b28903dc","status":"affected","versionType":"git"},{"version":"6.17.4","status":"affected","lessThan":"6.18","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/mm/gmap_helpers.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.18","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.18","versionType":"semver"},{"version":"6.18.4","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/s390/mm/gmap_helpers.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/2af2abbcbf8573100288e8f8aea2dab8a2a0ceb7"},{"url":"https://git.kernel.org/stable/c/2f393c228cc519ddf19b8c6c05bf15723241aa96"}],"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 - An unprivileged process inside an s390 KVM guest can drive the vulnerable path through ordinary page allocation and freeing, which invokes ESSA and reaches handle_essa(), __gmap_zap(), and gmap_helper_zap_one_page().\nAC:L - The attacker can use concurrent memory churn across vCPUs to control the relevant page-state transitions and can induce host backing-memory pressure by touching guest RAM, making repeated race attempts practical.\nPR:L - Although ESSA is privileged, unprivileged guest activity invokes it indirectly through arch_alloc_page() and arch_free_page() without requiring guest administrative capabilities.\nUI:N - Exploitation requires no action by another user once the attacker runs the memory-churning workload.\nS:U - The corruption affects memory within the same guest security authority and does not provide a demonstrated guest-to-host or cross-VM escape.\nC:H - Incorrectly discarding a stable swapped guest page can corrupt attacker-groomed guest kernel memory; successful exploitation could yield guest-kernel execution and unrestricted access to guest secrets.\nI:H - The flaw can replace preserved guest-page contents with a newly faulted page, enabling whole-page corruption of sensitive data or control structures and potentially guest-kernel code execution.\nA:H - Corruption of arbitrary guest data, page tables, or kernel control structures can panic, hang, or otherwise render the guest unavailable."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T12:12:23.055Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.18.4"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18","versionEndExcluding":"6.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.17.4"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}