CVE-2026-43459

Summary

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

ASoC: soc-core: flush delayed work before removing DAIs and widgets

When a sound card is unbound while a PCM stream is open, a use-after-free can occur in snd_soc_dapm_stream_event(), called from the close_delayed_work workqueue handler.

During unbind, snd_soc_unbind_card() flushes delayed work and then calls soc_cleanup_card_resources(). Inside cleanup, snd_card_disconnect_sync() releases all PCM file descriptors, and the resulting PCM close path can call snd_soc_dapm_stream_stop() which schedules new delayed work with a pmdown_time timer delay. Since this happens after the flush in snd_soc_unbind_card(), the new work is not caught. soc_remove_link_components() then frees DAPM widgets before this work fires, leading to the use-after-free.

The existing flush in soc_free_pcm_runtime() also cannot help as it runs after soc_remove_link_components() has already freed the widgets.

Add a flush in soc_cleanup_card_resources() after snd_card_disconnect_sync() (after which no new PCM closes can schedule further delayed work) and before soc_remove_link_dais() and soc_remove_link_components() (which tear down the structures the delayed work accesses).

Affected Software

Weaknesses

References

• https://git.kernel.org/stable/c/bf80a89da97285d9b877e0c6995e870d46b8025c
• https://git.kernel.org/stable/c/3887e514978d28216246360b46a9cb534969eb5a
• https://git.kernel.org/stable/c/231568afbc0cd25b8fb2a94ebf9738eabe1cf007
• https://git.kernel.org/stable/c/317a9298c54bb00319da73e5a7179f00e67fcbdf
• https://git.kernel.org/stable/c/eab71e11ce2447c1e01809cbc11eab4234cf8dc8
• https://git.kernel.org/stable/c/7d33e6140945482a07f8089ee86e13e02553ffdb
• https://git.kernel.org/stable/c/c054f0607c8bb1b1aa529bc109e4149298a1cccd
• https://git.kernel.org/stable/c/95bc5c225513fc3c4ce169563fb5e3929fbb938b

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