CVE-2026-98400
Received
Received - Intake
NULL Pointer Dereference in Linux Kernel kdump
Vulnerability report for CVE-2026-98400, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-14
Last updated on: 2026-10-14
Assigner: kernel.org
Description
Description
In the Linux kernel, the following vulnerability has been resolved:
s390/ipl: Fix NULL deref in kdump without re-IPL parm block
Some IPL types, like HMC FTP boot or QEMU direct kernel boot, might
not provide an IPL parameter block. In this case, reipl_type_init()
selects IPL_TYPE_UNKNOWN, and reipl_block_actual remains NULL.
kdump passes the re-IPL parameter block to the dump kernel through
os_info. Before commit 3b9678472bab ("s390/ipl: correct kdump reipl
block checksum calculation"), the os_info entry was added only for
IPL types which initialized reipl_block_actual. That commit moved the
os_info update to machine_crash_shutdown(), making it unconditional. As
a result, set_os_info_reipl_block() dereferences reipl_block_actual for
IPL_TYPE_UNKNOWN. This may happen to work by chance when address zero
contains readable lowcore data and the resulting empty os_info entry is
ignored by the dump kernel.
Skip the os_info update when no re-IPL parameter block is available.
Kdump then collect the dump and reboot without setting re-IPL parameter
block.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 3b9678472bab86ae654cf2c18d5dd551558045be |
| Linux | Linux | 3b9678472bab86ae654cf2c18d5dd551558045be |
| Linux | Linux | 3b9678472bab86ae654cf2c18d5dd551558045be |
| Linux | Linux | 3b9678472bab86ae654cf2c18d5dd551558045be |
| Linux | Linux | 3b9678472bab86ae654cf2c18d5dd551558045be |
| Linux | Linux | 4.17 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
