firmware: dmi-sysfs: Fix null-ptr-deref in dmi_sysfs_register_handle

Summary

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.

Timeline

1. Sep 15, 2025, 2:46 PM UTCCVE published
2. Jan 14, 2026, 6:00 PM UTCCISA SSVC assessment

   Exploitation: none · Automatable: no · Technical impact: partial

3. May 23, 2026, 3:28 PM UTCRecord last updated

Affected versions

• Linux Linux

  From 5.15.47 · fixed in 5.15.99; From 4.9.318 · fixed in 4.10; From 4.14.283 · fixed in 4.15; From 4.19.247 · fixed in 4.20; From 5.4.198 · fixed in 5.5; From 5.10.122 · fixed in 5.11; From 5.17.15 · fixed in 5.18; From 5.18.4 · fixed in 5.19

• Linux Linux

  5.19

References 4