CVE-2025-38056

In the Linux kernel, the following vulnerability has been resolved:

ASoC: SOF: Intel: hda: Fix UAF when reloading module

hda_generic_machine_select() appends -idisp to the tplg filename by allocating a new string with devm_kasprintf(), then stores the string right back into the global variable snd_soc_acpi_intel_hda_machines. When the module is unloaded, this memory is freed, resulting in a global variable pointing to freed memory. Reloading the module then triggers a use-after-free:

BUG: KFENCE: use-after-free read in string+0x48/0xe0

Use-after-free read at 0x00000000967e0109 (in kfence-#99): string+0x48/0xe0 vsnprintf+0x329/0x6e0 devm_kvasprintf+0x54/0xb0 devm_kasprintf+0x58/0x80 hda_machine_select.cold+0x198/0x17a2 [snd_sof_intel_hda_generic] sof_probe_work+0x7f/0x600 [snd_sof] process_one_work+0x17b/0x330 worker_thread+0x2ce/0x3f0 kthread+0xcf/0x100 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30

kfence-#99: 0x00000000198a940f-0x00000000ace47d9d, size=64, cache=kmalloc-64

allocated by task 333 on cpu 8 at 17.798069s (130.453553s ago): devm_kmalloc+0x52/0x120 devm_kvasprintf+0x66/0xb0 devm_kasprintf+0x58/0x80 hda_machine_select.cold+0x198/0x17a2 [snd_sof_intel_hda_generic] sof_probe_work+0x7f/0x600 [snd_sof] process_one_work+0x17b/0x330 worker_thread+0x2ce/0x3f0 kthread+0xcf/0x100 ret_from_fork+0x31/0x50 ret_from_fork_asm+0x1a/0x30

freed by task 1543 on cpu 4 at 141.586686s (6.665010s ago): release_nodes+0x43/0xb0 devres_release_all+0x90/0xf0 device_unbind_cleanup+0xe/0x70 device_release_driver_internal+0x1c1/0x200 driver_detach+0x48/0x90 bus_remove_driver+0x6d/0xf0 pci_unregister_driver+0x42/0xb0 __do_sys_delete_module+0x1d1/0x310 do_syscall_64+0x82/0x190 entry_SYSCALL_64_after_hwframe+0x76/0x7e

Fix it by copying the match array with devm_kmemdup_array() before we modify it.

Affected Software

References

• https://git.kernel.org/stable/c/2b49e68360eb6a1c03dc1642a51f7d9f6784c034
• https://git.kernel.org/stable/c/7dd7f39fce0022b386ef1ea5ffef92ecc7dfc6af
• https://git.kernel.org/stable/c/f9670b2e81e8a3cbf2e1e757190dd0b920a9d43f