CVE-2026-43459

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 sndsocdapmstreamevent(), called from the closedelayedwork workqueue handler.

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

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

Add a flush in soccleanupcardresources() after sndcarddisconnectsync() (after which no new PCM closes can schedule further delayed work) and before socremovelinkdais() and socremovelinkcomponents() (which tear down the structures the delayed work accesses).