CVE-2026-98399
Received
Received - Intake
Null Pointer Dereference in Linux Kernel s390 IPL
Vulnerability report for CVE-2026-98399, 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 dump_reipl without re-IPL parm block
Unlike kdump, which passes the re-IPL parameter block through os_info,
the stand-alone dump passes it through the IPL parm block address and
checksum in lowcore.
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. Nevertheless,
dump_reipl_run() unconditionally dereferences it when preparing the
lowcore fields. This may happen to work by chance when address zero
contains readable lowcore data. A zero IPL parameter block address is
then stored in lowcore, causing the stand-alone dumper to enter disabled
wait after completing the dump.
Explicitly store a zero IPL parameter block address and checksum when no
re-IPL parameter block is available. This does not change the behavior:
the stand-alone dumper completes the dump and halts, while valid re-IPL
parameter blocks continue to be handled as before.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| Linux | Linux | 099b765139929efdcf232f8870804accf8c4cdc5 |
| Linux | Linux | 099b765139929efdcf232f8870804accf8c4cdc5 |
| Linux | Linux | 099b765139929efdcf232f8870804accf8c4cdc5 |
| Linux | Linux | 099b765139929efdcf232f8870804accf8c4cdc5 |
| Linux | Linux | 099b765139929efdcf232f8870804accf8c4cdc5 |
| Linux | Linux | 2.6.30 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
