{"id":"CVE-2026-89923","revision":"0ec24edee6cf4bb5a1c010dd80eaf0f4","records":[{"revision":"0ec24edee6cf4bb5a1c010dd80eaf0f4","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-89923","aliases":[],"title":"KVM: s390: Free guest debug data on vcpu destroy","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: s390: Free guest debug data on vcpu destroy\n\nkvm_s390_clear_bp_data() is only called from\nkvm_arch_vcpu_ioctl_set_guest_debug(), i.e. when user space changes or\ndisables debugging. A vCPU that is destroyed while hardware breakpoints\nare still armed - the normal case when the VMM just exits or crashes -\nleaks hw_bp_info, hw_wp_info and all old_data buffers, since generic KVM\nfrees the vCPU right after kvm_arch_vcpu_destroy().\n\nThat is bounded by MAX_BP_COUNT entries, so roughly 8 KiB per vCPU, but\nit is unbounded over VM lifetimes. The allocations are\nGFP_KERNEL_ACCOUNT, so the charge also outlives the exiting process and\npins dying memcgs.\n\nFix by clearing the debug data on vCPU destruction. Calling it\nunconditionally is fine: struct kvm_vcpu is zero allocated, so for a vCPU\nthat never enabled debugging the counters are 0 and the pointers NULL.","state":0,"publishedAt":"2026-09-16T10:32:16.765+00:00","modifiedAt":"2026-10-19T08:54:58.219+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/s390/kvm/kvm-s390.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"053f2068cf9b0654b651fed5ad7649d3deb982bf\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"6c996b12bbe4a6023076e8eee3cfaf2cc99db76c\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"d6280fc540d8f4653c9b54a78cb747e128070f5e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"544a5a665019cef394ce8bda97fa7a2cab253781\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"b5acacfdb8966abff91836c1c5bd7da59d8a526e\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"e4d8b7f176b976474e0800ba71ee2dfa3ce263c9\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"27291e2165b6de70c476b7b675308113edd69a60\",\n                            \"lessThan\": \"e7f698b09d4a7c36b299acf680fc50fe868e2bcd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"affected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/s390/kvm/kvm-s390.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3.16\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"3.16\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.10.270\",\n                            \"lessThanOrEqual\": \"5.10.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"5.15.221\",\n                            \"lessThanOrEqual\": \"5.15.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.1.188\",\n                            \"lessThanOrEqual\": \"6.1.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.157\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.110\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.51\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.5\",\n                            \"lessThanOrEqual\": \"7.2.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.3\",\n                            \"lessThanOrEqual\": \"*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"original_commit_for_fix\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/053f2068cf9b0654b651fed5ad7649d3deb982bf","https://git.kernel.org/stable/c/6c996b12bbe4a6023076e8eee3cfaf2cc99db76c","https://git.kernel.org/stable/c/d6280fc540d8f4653c9b54a78cb747e128070f5e","https://git.kernel.org/stable/c/544a5a665019cef394ce8bda97fa7a2cab253781","https://git.kernel.org/stable/c/9a32c4c6a6c23b7f5bf765eb5b83ba7f64a8ec63","https://git.kernel.org/stable/c/b5acacfdb8966abff91836c1c5bd7da59d8a526e","https://git.kernel.org/stable/c/e4d8b7f176b976474e0800ba71ee2dfa3ce263c9","https://git.kernel.org/stable/c/e7f698b09d4a7c36b299acf680fc50fe868e2bcd"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-89923","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-89923","identifiers":["CVE-2026-89923"]},"retained":false,"historicalAffected":[]}],"coverage":[]}