{"id":"CVE-2026-98400","revision":"e0d4dbab834a4f5da02d0d79fbcf3f6b","records":[{"revision":"e0d4dbab834a4f5da02d0d79fbcf3f6b","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98400","aliases":[],"title":"s390/ipl: Fix NULL deref in kdump without re-IPL parm block","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ns390/ipl: Fix NULL deref in kdump without re-IPL parm block\n\nSome IPL types, like HMC FTP boot or QEMU direct kernel boot, might\nnot provide an IPL parameter block. In this case, reipl_type_init()\nselects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.\n\nkdump passes the re-IPL parameter block to the dump kernel through\nos_info. Before commit 3b9678472bab (\"s390/ipl: correct kdump reipl\nblock checksum calculation\"), the os_info entry was added only for\nIPL types which initialized reipl_block_actual. That commit moved the\nos_info update to machine_crash_shutdown(), making it unconditional. As\na result, set_os_info_reipl_block() dereferences reipl_block_actual for\nIPL_TYPE_UNKNOWN. This may happen to work by chance when address zero\ncontains readable lowcore data and the resulting empty os_info entry is\nignored by the dump kernel.\n\nSkip the os_info update when no re-IPL parameter block is available.\nKdump then collect the dump and reboot without setting re-IPL parameter\nblock.","state":0,"publishedAt":"2026-10-14T13:26:00.872+00:00","modifiedAt":"2026-10-19T09:18:53.762+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/kernel/ipl.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"3b9678472bab86ae654cf2c18d5dd551558045be\",\n                            \"lessThan\": \"030e88812435fc5d6aa42eee41fa77b5ea620327\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b9678472bab86ae654cf2c18d5dd551558045be\",\n                            \"lessThan\": \"92d0829eae257544b6b0faccb6e7079c45e22d48\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b9678472bab86ae654cf2c18d5dd551558045be\",\n                            \"lessThan\": \"50f9c40768e84f30d374235b3ee3850a94d9ac29\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b9678472bab86ae654cf2c18d5dd551558045be\",\n                            \"lessThan\": \"b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"3b9678472bab86ae654cf2c18d5dd551558045be\",\n                            \"lessThan\": \"7f918871112e8e7c581e99eb8e545af4e59c8367\",\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/kernel/ipl.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"4.17\",\n                            \"status\": \"affected\"\n                        },\n                        {\n                            \"version\": \"0\",\n                            \"lessThan\": \"4.17\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.6.158\",\n                            \"lessThanOrEqual\": \"6.6.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.12.111\",\n                            \"lessThanOrEqual\": \"6.12.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"6.18.53\",\n                            \"lessThanOrEqual\": \"6.18.*\",\n                            \"status\": \"unaffected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.7\",\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/030e88812435fc5d6aa42eee41fa77b5ea620327","https://git.kernel.org/stable/c/92d0829eae257544b6b0faccb6e7079c45e22d48","https://git.kernel.org/stable/c/50f9c40768e84f30d374235b3ee3850a94d9ac29","https://git.kernel.org/stable/c/b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd","https://git.kernel.org/stable/c/7f918871112e8e7c581e99eb8e545af4e59c8367"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98400","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98400","identifiers":["CVE-2026-98400"]},"retained":false,"historicalAffected":[]}],"coverage":[]}