CVE-2026-53348
Received Received - Intake

NULL Pointer Dereference in Linux Kernel ASoC SDCA

Publication date: 2026-07-01

Last updated on: 2026-07-01

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: ASoC: SDCA: fix NULL pointer dereference in sdca_dev_unregister_functions sdca_dev_unregister_functions() iterates over all SDCA function descriptors and calls sdca_dev_unregister() on each func_dev without checking for NULL. When a function registration has failed partway through, or the device cleanup races with probe deferral, func_dev entries may be NULL, leading to a kernel oops: BUG: kernel NULL pointer dereference, address: 0000000000000040 RIP: 0010:device_del+0x1e/0x3e0 Call Trace: sdca_dev_unregister_functions+0x37/0x60 [snd_soc_sdca] release_nodes+0x35/0xb0 devres_release_all+0x90/0x100 device_unbind_cleanup+0xe/0x80 device_release_driver_internal+0x1c1/0x200 bus_remove_device+0xc6/0x130 device_del+0x161/0x3e0 device_unregister+0x17/0x60 sdw_delete_slave+0xb6/0xd0 [soundwire_bus] sdw_bus_master_delete+0x1e/0x50 [soundwire_bus] ... sof_probe_work+0x19/0x30 [snd_sof] This was observed on a Lenovo ThinkPad X1 Carbon G14 (Panther Lake) with the SOF audio driver probe failing due to missing Panther Lake firmware, causing the subsequent cleanup of SoundWire devices to trigger the crash. Fix this with three changes: 1) Add a NULL guard in sdca_dev_unregister() so that callers do not need to pre-validate the pointer (defense in depth). 2) In sdca_dev_unregister_functions(), skip NULL func_dev entries and clear func_dev to NULL after unregistration, making the function idempotent and safe against double-invocation. 3) In sdca_dev_register_functions(), roll back all previously registered functions when a later one fails, so the function array is never left in a partially-populated state.

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Meta Information

Published
2026-07-01
Last Modified
2026-07-01
Generated
2026-07-01
AI Q&A
2026-07-01
EPSS Evaluated
N/A
NVD
CVE-2026-53348
EUVD
EUVD-2026-40982

Affected Vendors & Products

Showing 1 associated CPE
Vendor Product Version / Range
linux linux_kernel *

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Exploitability

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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability exists in the Linux kernel's ASoC SDCA component, specifically in the function sdca_dev_unregister_functions. The function iterates over all SDCA function descriptors and calls sdca_dev_unregister on each without checking if the pointer is NULL. If a function registration fails partway or if device cleanup races with probe deferral, some func_dev entries may be NULL. This leads to a NULL pointer dereference and causes a kernel crash (kernel oops).

The issue was observed on a Lenovo ThinkPad X1 Carbon G14 where the SOF audio driver probe failed due to missing firmware, triggering the crash during SoundWire device cleanup.

The fix involved adding NULL pointer checks, skipping NULL entries during unregistration, clearing entries after unregistration to prevent double calls, and rolling back partially registered functions to avoid leaving the function array in an inconsistent state.

Impact Analysis

This vulnerability can cause a kernel crash (kernel oops) on affected Linux systems when certain audio driver functions fail to register properly or during device cleanup. This can lead to system instability, unexpected reboots, or loss of functionality related to audio devices.

Detection Guidance

This vulnerability manifests as a kernel NULL pointer dereference leading to a kernel oops. Detection involves monitoring kernel logs for crash messages related to sdca_dev_unregister_functions or device_del.

Look for kernel oops messages similar to: "BUG: kernel NULL pointer dereference, address: 0000000000000040" and call traces involving sdca_dev_unregister_functions, device_del, or soundwire_bus modules.

You can check kernel logs using commands like:

  • dmesg | grep -i 'sdca_dev_unregister_functions'
  • journalctl -k | grep -i 'NULL pointer dereference'
  • journalctl -k | grep -i 'device_del'

Additionally, monitoring for failed audio driver probes or SoundWire device cleanup failures may indicate the issue.

Mitigation Strategies

To mitigate this vulnerability, update the Linux kernel to a version that includes the fix for the NULL pointer dereference in sdca_dev_unregister_functions.

The fix involves:

  • Adding a NULL pointer check in sdca_dev_unregister() to prevent dereferencing NULL pointers.
  • Skipping NULL func_dev entries in sdca_dev_unregister_functions() and clearing them after unregistration to make the function safe and idempotent.
  • Rolling back all previously registered functions if a later registration fails to avoid partially populated function arrays.

Until the kernel is updated, avoid using affected audio drivers or devices that trigger the SoundWire device cleanup process, such as those requiring Panther Lake firmware, to reduce the risk of kernel crashes.

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