CVE-2023-53250: firmware: dmi-sysfs: Fix null-ptr-deref in dmi_sysfs_register_handle

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-09-15 · updated 2026-06-17
Weakness: CWE-476

Description

In the Linux kernel, the following vulnerability has been resolved: firmware: dmi-sysfs: Fix null-ptr-deref in dmi_sysfs_register_handle KASAN reported a null-ptr-deref error: KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f] CPU: 0 PID: 1373 Comm: modprobe Hardware name: QEMU Standard PC (i440FX + PIIX, 1996) RIP: 0010:dmi_sysfs_entry_release ... Call Trace: <TASK> kobject_put dmi_sysfs_register_handle (drivers/firmware/dmi-sysfs.c:540) dmi_sysfs dmi_decode_table (drivers/firmware/dmi_scan.c:133) dmi_walk (drivers/firmware/dmi_scan.c:1115) dmi_sysfs_init (drivers/firmware/dmi-sysfs.c:149) dmi_sysfs do_one_initcall (init/main.c:1296) ... Kernel panic - not syncing: Fatal exception Kernel Offset: 0x4000000 from 0xffffffff81000000 ---[ end Kernel panic - not syncing: Fatal exception ]--- It is because previous patch added kobject_put() to release the memory which will call dmi_sysfs_entry_release() and list_del(). However, list_add_tail(entry->list) is called after the error block, so the list_head is uninitialized and cannot be deleted. Move error handling to after list_add_tail to fix this.

Affected products

Linux kernel: from 4.9.318 before 4.10; from 4.14.283 before 4.15; from 4.19.247 before 4.20; from 5.4.198 before 5.5; from 5.10.122 before 5.11; from 5.15.47 before 5.15.99 — fixed in 4.10, 4.15, 4.20, 5.11, 5.15.99, 5.18

How to fix

Upgrade to a fixed version: Linux kernel 4.10, 4.15, 4.20, 5.11. Check the vendor advisory for mitigations.

References

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