CVE-2023-53480: kobject: Add sanity check for kset->kobj.ktype in kset_register()

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-10-01 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: kobject: Add sanity check for kset->kobj.ktype in kset_register() When I register a kset in the following way: static struct kset my_kset; kobject_set_name(&my_kset.kobj, "my_kset"); ret = kset_register(&my_kset); A null pointer dereference exception is occurred: [ 4453.568337] Unable to handle kernel NULL pointer dereference at \ virtual address 0000000000000028 ... ... [ 4453.810361] Call trace: [ 4453.813062] kobject_get_ownership+0xc/0x34 [ 4453.817493] kobject_add_internal+0x98/0x274 [ 4453.822005] kset_register+0x5c/0xb4 [ 4453.825820] my_kobj_init+0x44/0x1000 [my_kset] ... ... Because I didn't initialize my_kset.kobj.ktype. According to the description in Documentation/core-api/kobject.rst: - A ktype is the type of object that embeds a kobject. Every structure that embeds a kobject needs a corresponding ktype. So add sanity check to make sure kset->kobj.ktype is not NULL.

Affected products

Linux kernel: from 4.19 before 4.19.295; from 4.20 before 5.4.257; from 5.5 before 5.10.197; from 5.11 before 5.15.133; from 5.16 before 6.1.55; from 6.2 before 6.5.5 — fixed in 4.19.295, 5.10.197, 5.15.133, 5.4.257, 6.1.55, 6.5.5

How to fix

Upgrade to a fixed version: Linux kernel 4.19.295, 5.10.197, 5.15.133, 5.4.257. Check the vendor advisory for mitigations.

References

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