{"id":"CVE-2026-98400","title":"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","summary":"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 …","severity":"medium","published":"2026-10-14","updated":"2026-10-14","sourceUpdated":"2026-10-14T14:17:51.010","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-98400","references":[{"url":"https://git.kernel.org/stable/c/030e88812435fc5d6aa42eee41fa77b5ea620327","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/50f9c40768e84f30d374235b3ee3850a94d9ac29","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7f918871112e8e7c581e99eb8e545af4e59c8367","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/92d0829eae257544b6b0faccb6e7079c45e22d48","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98400.json"},{"url":"https://access.redhat.com/security/cve/CVE-2026-98400"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2552215"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98400"},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98400"},{"url":"https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-98400.mbox"}],"tags":["nvd","cve.org","csaf","vex","red-hat"],"ingestedAt":"2026-10-14T15:36:13.980Z","vendor":"Linux","product":"Linux","affected":["Linux >= 3b9678472bab86ae654cf2c18d5dd551558045be < 030e88812435fc5d6aa42eee41fa77b5ea620327","Linux >= 3b9678472bab86ae654cf2c18d5dd551558045be < 92d0829eae257544b6b0faccb6e7079c45e22d48","Linux >= 3b9678472bab86ae654cf2c18d5dd551558045be < 50f9c40768e84f30d374235b3ee3850a94d9ac29","Linux >= 3b9678472bab86ae654cf2c18d5dd551558045be < b6bf82bc5e00afaf836f8bb9a676bffc182a6bbd","Linux >= 3b9678472bab86ae654cf2c18d5dd551558045be < 7f918871112e8e7c581e99eb8e545af4e59c8367","Linux 4.17"],"cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","cvssSource":"vendor","cwe":["CWE-476"],"epss":0.002,"epssPercentile":0.0977,"slug":"CVE-2026-98400","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.\n\n## Vendor advisories\n\n- **Red Hat VEX** · Low · affected: Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, Red Hat OpenShift Container Platform 4 · no fix planned: Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9, … · updated 2026-10-18 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-98400.json)","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":224109,"id":"CVE-2026-98400","ts":1792324925035,"field":"cvss","old":null,"new":"5.5"},{"seq":224108,"id":"CVE-2026-98400","ts":1792324925035,"field":"severity","old":"none","new":"medium"}]}