Linux Kernel up to 6.12.109/6.18.50/7.2.4 kexec powerpc/kexec_file kexec_extra_fdt_size_ppc64 rmem null pointer dereference

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4.2	$0-$5k	0.00-

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. It has been rated as problematic. Affected is the function kexec_extra_fdt_size_ppc64 of the file powerpc/kexec_file of the component kexec. This manipulation of the argument rmem causes null pointer dereference. This vulnerability is handled as CVE-2026-89963. It is possible to launch the attack on the local host. There is not any exploit available. Upgrading the affected component is advised.

Detailsinfo

A vulnerability classified as problematic was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4. Affected by this vulnerability is the function kexec_extra_fdt_size_ppc64 of the file powerpc/kexec_file of the component kexec. The manipulation of the argument rmem with an unknown input leads to a null pointer dereference vulnerability. The CWE definition for the vulnerability is CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. As an impact it is known to affect availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: powerpc/kexec_file: Fix null-ptr-def in extra size calculation A static Sashiko AI review identified a potential NULL pointer dereference in kexec_extra_fdt_size_ppc64(). On platforms without any reserved memory regions, get_reserved_memory_ranges() can return 0 while leaving 'rmem' unallocated as NULL. Passing it directly leads to a kernel panic when evaluating 'rmem->nr_ranges'. Add a NULL check for 'rmem' to prevent this crash.

It is possible to read the advisory at git.kernel.org. This vulnerability is known as CVE-2026-89963 since 09/11/2026. The exploitation appears to be easy. Attacking locally is a requirement. The exploitation needs additional levels of successful authentication. Technical details of the vulnerability are known, but there is no available exploit.

Upgrading to version 6.12.110, 6.18.51, 7.2.5 or 7.3-rc1 eliminates this vulnerability. Applying the patch 11ef1c2a5dbe0bd8c1345f59bab7331d352f02cf/df45337587db21c502fe5251d3bcc7887428f4fb/4ff3d9fd71c7bc2fc81afdac1970d9c55a5c0dea/761eda315a6e1fda3e8e2185b28430771fb1ac29 is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

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Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.109
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 4.4
VulDB Meta Temp Score: 4.2

VulDB Base Score: 4.4
VulDB Temp Score: 4.2
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
CAPEC: 🔒
ATT&CK: 🔒

Physical: Partially
Local: Yes
Remote: No

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.51/7.2.5/7.3-rc1
Patch: 11ef1c2a5dbe0bd8c1345f59bab7331d352f02cf/df45337587db21c502fe5251d3bcc7887428f4fb/4ff3d9fd71c7bc2fc81afdac1970d9c55a5c0dea/761eda315a6e1fda3e8e2185b28430771fb1ac29

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-89963 (🔒)
GCVE (CVE): GCVE-0-2026-89963
GCVE (VulDB): GCVE-100-405811

Entryinfo

Created: 09/16/2026 15:06
Changes: 09/16/2026 15:06 (61)
Complete: 🔍
Cache ID: 216::103

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